2023
E. Arpa Yeşiltepe M., M. Ekinci
Sigma vector calculations in nodal aberration theory and experimental validation using a Cassegrain telescope Journal Article
In: Optic Express, vol. 31, iss. 25, pp. 42373, 2023, ISBN: 1094-4087.
Abstract | Links | BibTeX | Tags: CeFO related, metrology
@article{M.2023,
title = {Sigma vector calculations in nodal aberration theory and experimental validation using a Cassegrain telescope},
author = {Yeşiltepe M., E. Arpa, M. Ekinci, O. Karci, J.P. Rolland},
doi = {10.1364/OE.502744},
isbn = {1094-4087},
year = {2023},
date = {2023-12-01},
journal = {Optic Express},
volume = {31},
issue = {25},
pages = {42373},
abstract = {Nodal Aberration Theory (NAT) was developed to explain the field dependency of aberration field centers in the image plane of nominally rotationally symmetric optical systems that have lost their symmetry through misalignments. A new insight into the theory led to calculating the sigma vectors, which locate the aberration field centers, using the angle between a real-ray trace of the optical axis ray (OAR) and the normal of the local surface where “local” refers to the object and image optical spaces of that surface. Here, we detail the sigma vector calculations for general optical systems and provide an experimental investigation of a misaligned system with a high-precision customized Cassegrain telescope. In the simulations, a Newtonian telescope, a Cassegrain telescope, and a three-mirror anastigmat telescope were misaligned intentionally in ray-tracing software. The sigma vectors were calculated analytically for the third-order aberrations of astigmatism and coma. Experimentally, the same perturbations were implemented for the Cassegrain telescope system, and the aberrations were quantified through interferometric measurements on a grid of field points in the image plane that verified the analytical derivation and simulations.},
keywords = {CeFO related, metrology},
pubstate = {published},
tppubtype = {article}
}
Nodal Aberration Theory (NAT) was developed to explain the field dependency of aberration field centers in the image plane of nominally rotationally symmetric optical systems that have lost their symmetry through misalignments. A new insight into the theory led to calculating the sigma vectors, which locate the aberration field centers, using the angle between a real-ray trace of the optical axis ray (OAR) and the normal of the local surface where “local” refers to the object and image optical spaces of that surface. Here, we detail the sigma vector calculations for general optical systems and provide an experimental investigation of a misaligned system with a high-precision customized Cassegrain telescope. In the simulations, a Newtonian telescope, a Cassegrain telescope, and a three-mirror anastigmat telescope were misaligned intentionally in ray-tracing software. The sigma vectors were calculated analytically for the third-order aberrations of astigmatism and coma. Experimentally, the same perturbations were implemented for the Cassegrain telescope system, and the aberrations were quantified through interferometric measurements on a grid of field points in the image plane that verified the analytical derivation and simulations.
Yesiltepe, M.; Bauer, A.; Karci, O.; Rolland, J. P.
Sigma vector calculations in nodal aberration theory and experimental validation using a Cassegrain telescope Journal Article
In: Optics Express, vol. 31, iss. 25, pp. 42373-42387, 2023.
Abstract | Links | BibTeX | Tags: CeFO related, design
@article{Yesiltepe2023,
title = {Sigma vector calculations in nodal aberration theory and experimental validation using a Cassegrain telescope},
author = {M. Yesiltepe and A. Bauer and O. Karci and J. P. Rolland},
doi = {https://doi.org/10.1364/OE.502744},
year = {2023},
date = {2023-12-01},
urldate = {2023-12-01},
journal = {Optics Express},
volume = {31},
issue = {25},
pages = {42373-42387},
abstract = {Nodal Aberration Theory (NAT) was developed to explain the field dependency of aberration field centers in the image plane of nominally rotationally symmetric optical systems that have lost their symmetry through misalignments. A new insight into the theory led to calculating the sigma vectors, which locate the aberration field centers, using the angle between a real-ray trace of the optical axis ray (OAR) and the normal of the local surface where “local” refers to the object and image optical spaces of that surface. Here, we detail the sigma vector calculations for general optical systems and provide an experimental investigation of a misaligned system with a high-precision customized Cassegrain telescope. In the simulations, a Newtonian telescope, a Cassegrain telescope, and a three-mirror anastigmat telescope were misaligned intentionally in ray-tracing software. The sigma vectors were calculated analytically for the third-order aberrations of astigmatism and coma. Experimentally, the same perturbations were implemented for the Cassegrain telescope system, and the aberrations were quantified through interferometric measurements on a grid of field points in the image plane that verified the analytical derivation and simulations.},
keywords = {CeFO related, design},
pubstate = {published},
tppubtype = {article}
}
Nodal Aberration Theory (NAT) was developed to explain the field dependency of aberration field centers in the image plane of nominally rotationally symmetric optical systems that have lost their symmetry through misalignments. A new insight into the theory led to calculating the sigma vectors, which locate the aberration field centers, using the angle between a real-ray trace of the optical axis ray (OAR) and the normal of the local surface where “local” refers to the object and image optical spaces of that surface. Here, we detail the sigma vector calculations for general optical systems and provide an experimental investigation of a misaligned system with a high-precision customized Cassegrain telescope. In the simulations, a Newtonian telescope, a Cassegrain telescope, and a three-mirror anastigmat telescope were misaligned intentionally in ray-tracing software. The sigma vectors were calculated analytically for the third-order aberrations of astigmatism and coma. Experimentally, the same perturbations were implemented for the Cassegrain telescope system, and the aberrations were quantified through interferometric measurements on a grid of field points in the image plane that verified the analytical derivation and simulations.
Xiong, P.; Nikolov, D. K.; Cheng, F.; Rolland, J. P.; Vamivakas, A. N.
All-dielectric hybrid VIS-NIR dual-function metasurface Journal Article
In: ArXiv, vol. 2310, pp. 09393, 2023.
Abstract | Links | BibTeX | Tags: CeFO related, design
@article{Xiong2023,
title = {All-dielectric hybrid VIS-NIR dual-function metasurface},
author = {P. Xiong and D. K. Nikolov and F. Cheng and J. P. Rolland and A. N. Vamivakas },
url = {https://arxiv.org/abs/2310.09393},
doi = {https://doi.org/10.48550/arXiv.2310.09393},
year = {2023},
date = {2023-10-13},
urldate = {2023-10-13},
journal = {ArXiv},
volume = {2310},
pages = {09393},
abstract = {Metasurfaces are a promising technology that can serve as a compact alternative to conventional optics while providing multiple functions depending on the properties of the incident light, such as the wavelength, polarization, and incident angle. Here, we demonstrate a hybrid VIS-NIR dielectriac metasurface that can reflect 940 nm light into a specified direction while transmitting visible light (450-750 nm). The dual functionality is realized by combining an aperiodic distributed Bragg reflector with dielectric meta-tokens. Experimental demonstration is also reported, showing an anomalous reflection of near-infrared (NIR) light within a 20o full field-of-view (FOV) and the transmission of wavelengths from 450 nm to 750 nm.},
keywords = {CeFO related, design},
pubstate = {published},
tppubtype = {article}
}
Metasurfaces are a promising technology that can serve as a compact alternative to conventional optics while providing multiple functions depending on the properties of the incident light, such as the wavelength, polarization, and incident angle. Here, we demonstrate a hybrid VIS-NIR dielectriac metasurface that can reflect 940 nm light into a specified direction while transmitting visible light (450-750 nm). The dual functionality is realized by combining an aperiodic distributed Bragg reflector with dielectric meta-tokens. Experimental demonstration is also reported, showing an anomalous reflection of near-infrared (NIR) light within a 20o full field-of-view (FOV) and the transmission of wavelengths from 450 nm to 750 nm.
J. Steidle, J. Howard; J. Papa; Rolland, J. P.
Controlling First-order Pupil Location Conference
2023.
Abstract | Links | BibTeX | Tags: CeFO related, Optical design
@conference{Steidle2023,
title = {Controlling First-order Pupil Location},
author = {Steidle, J., J. Howard; J. Papa, and J. P. Rolland},
doi = {doi.org/10.1117/12.2692122},
year = {2023},
date = {2023-09-14},
journal = {SPIE},
abstract = {We consider the requirements for first-order pupil location control using the matrix method for both finite-conjugate systems and afocal systems at infinite imaging conjugates. We show that two-element systems allow for only limited pupil location control, while with three elements or more the first-order pupil locations can be freely and independently controlled.},
keywords = {CeFO related, Optical design},
pubstate = {published},
tppubtype = {conference}
}
We consider the requirements for first-order pupil location control using the matrix method for both finite-conjugate systems and afocal systems at infinite imaging conjugates. We show that two-element systems allow for only limited pupil location control, while with three elements or more the first-order pupil locations can be freely and independently controlled.
M.; D. K. Nikolov Ferguson, M. Pomerantz
Development of a Process Chain to Measure Freeform Optics using an Optical Coordinate Measuring Machine Conference
Optica Publishing Group, Québec City, Québec Canada, 2023, ISBN: 978-1-957171-22-7.
@conference{Ferguson2023,
title = {Development of a Process Chain to Measure Freeform Optics using an Optical Coordinate Measuring Machine},
author = {Ferguson, M.; D. K. Nikolov, M. Pomerantz, F. Wolfs, S. Novak, C. Lee, J. Lau, M. Davies, J. P. Rolland},
isbn = {978-1-957171-22-7},
year = {2023},
date = {2023-06-04},
publisher = {Optica Publishing Group},
address = {Québec City, Québec Canada},
abstract = {A process chain for measuring and analyzing freeform optics is developed for the OptiPro UltraSurf 5x 400 optical coordinate measuring machine. A test case of molded BD6 Alvarez lenses demonstrates measurement repeatability and reproducibility.},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
A process chain for measuring and analyzing freeform optics is developed for the OptiPro UltraSurf 5x 400 optical coordinate measuring machine. A test case of molded BD6 Alvarez lenses demonstrates measurement repeatability and reproducibility.
Shanmugam, Prithiviraj; Lambropoulos, John C.; Davies, Matthew A.
Grinding of silicon carbide for optical surface fabrication. Part II. Subsurface damage Journal Article
In: Applied Optics, vol. 62, iss. 14, pp. 3778-3796, 2023.
@article{Davies2023,
title = {Grinding of silicon carbide for optical surface fabrication. Part II. Subsurface damage},
author = {Prithiviraj Shanmugam and John C. Lambropoulos and Matthew A. Davies},
year = {2023},
date = {2023-06-01},
urldate = {2023-06-01},
journal = {Applied Optics},
volume = {62},
issue = {14},
pages = {3778-3796},
abstract = {This paper is the second part of a study of the grinding of three different grades of silicon carbide (SiC) under the same conditions. In this paper, subsurface damage is analyzed using magnetorheological finishing (MRF). The MRF ribbon is brought into contact with the surface and allowed to dwell for different lengths of time to produce dimples or spots at different depths. The roughness parameters are evaluated at the base of the spots. As the spot depth increases the roughness parameters decrease, eventually saturating at a steady-state value. The depth at which saturation occurs is much greater than the initial peak-to-value roughness of the surface and is therefore assumed to be correlated to the depth of subsurface damage in the material. Estimates of the damage depth are comparable to other estimates given in the literature. The validity of this technique is assessed across different grades of SiC under different grinding conditions, and limitations are identified. The study shows that the microstructure of the SiC grade is a major factor that affects the validity of the technique. The technique is suitable for SiC grades that have a more homogeneous microstructure such as chemical vapor deposited or chemical vapor composite grades. The presence of porosity as in the direct sintered grade, or the presence of a secondary phase, for example, silicon in the reaction-bonded and silicon-infiltrated grades, could hinder the technique from providing conclusive results.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This paper is the second part of a study of the grinding of three different grades of silicon carbide (SiC) under the same conditions. In this paper, subsurface damage is analyzed using magnetorheological finishing (MRF). The MRF ribbon is brought into contact with the surface and allowed to dwell for different lengths of time to produce dimples or spots at different depths. The roughness parameters are evaluated at the base of the spots. As the spot depth increases the roughness parameters decrease, eventually saturating at a steady-state value. The depth at which saturation occurs is much greater than the initial peak-to-value roughness of the surface and is therefore assumed to be correlated to the depth of subsurface damage in the material. Estimates of the damage depth are comparable to other estimates given in the literature. The validity of this technique is assessed across different grades of SiC under different grinding conditions, and limitations are identified. The study shows that the microstructure of the SiC grade is a major factor that affects the validity of the technique. The technique is suitable for SiC grades that have a more homogeneous microstructure such as chemical vapor deposited or chemical vapor composite grades. The presence of porosity as in the direct sintered grade, or the presence of a secondary phase, for example, silicon in the reaction-bonded and silicon-infiltrated grades, could hinder the technique from providing conclusive results.
J. Goodsell, A. Urbas; Rolland, J. P.
Design, fabrication, and characterization of large metalenses Conference
SPIE, 2023, ISBN: 9781510663664.
Abstract | Links | BibTeX | Tags: CeFO related, metrology
@conference{Goodsell2023b,
title = {Design, fabrication, and characterization of large metalenses},
author = {Goodsell, J., A. Urbas, J. Leger, and J.P. Rolland},
editor = {Fan, Jonathan A; Chang-Hasnain, Connie J; Zhou, Weimin},
url = {San Fransisco, CA, USA},
doi = {10.1117/12.2649327},
isbn = {9781510663664},
year = {2023},
date = {2023-03-17},
pages = {25},
publisher = {SPIE},
abstract = {This work demonstrates the utility of a design, fabrication, and testing loop on 10 mm diameter metalenses to accelerate large-scale production of flat optics. By enabling rapid measurement and analysis of metalenses, it is possible to identify differences between designed performance and as-built performance quickly and correlate those to process characteristics. This accelerated feedback between the design, fabrication, and testing is expected to enable higher yields of better-performing metalenses.},
keywords = {CeFO related, metrology},
pubstate = {published},
tppubtype = {conference}
}
This work demonstrates the utility of a design, fabrication, and testing loop on 10 mm diameter metalenses to accelerate large-scale production of flat optics. By enabling rapid measurement and analysis of metalenses, it is possible to identify differences between designed performance and as-built performance quickly and correlate those to process characteristics. This accelerated feedback between the design, fabrication, and testing is expected to enable higher yields of better-performing metalenses.
Y. Fan, D. K. Nikolov; Rolland, J. P.
Automated generation of high-accuracy CAD models for metaform design, fabrication, and testing Conference
SPIE, 2023, ISBN: 9781510660038.
Abstract | Links | BibTeX | Tags: CeFO related, design, fabrication
@conference{Fan2023b,
title = {Automated generation of high-accuracy CAD models for metaform design, fabrication, and testing},
author = {Fan, Y., D.K. Nikolov, A.N. Vamivakas, and J.P. Rolland},
editor = {Kress, Bernard C; Peroz, Christophe},
url = {San Francisco, CA, USA},
doi = {10.1117/12.2647769},
isbn = {9781510660038},
year = {2023},
date = {2023-03-16},
pages = {107},
publisher = {SPIE},
abstract = {Metaforms are novel optical components formed by conforming a metasurface to a freeform substrate. Metaforms can be a powerful solution when designing compact imaging systems such as augmented reality displays. Given the rotationally variant nature of the metaform substrate and the difficulty of metasurface fabrication on curved substrates, the proper alignment of the metasurface nanofeatures to the freeform substrate is essential. Thus, to seamlessly bridge the metaform design, manufacturing, and metrology, we developed a software tool that automatically generates ISO standard highaccuracy CAD models for the designed metaform components},
keywords = {CeFO related, design, fabrication},
pubstate = {published},
tppubtype = {conference}
}
Metaforms are novel optical components formed by conforming a metasurface to a freeform substrate. Metaforms can be a powerful solution when designing compact imaging systems such as augmented reality displays. Given the rotationally variant nature of the metaform substrate and the difficulty of metasurface fabrication on curved substrates, the proper alignment of the metasurface nanofeatures to the freeform substrate is essential. Thus, to seamlessly bridge the metaform design, manufacturing, and metrology, we developed a software tool that automatically generates ISO standard highaccuracy CAD models for the designed metaform components
P. Xiong, J. Goodsell; Vamivakas, A. N
Efficient all-dielectric metasurface in-coupler for waveguide-based near-eye display Conference
SPIE, San Fransisco, CA, USA, 2023, ISBN: 9781510660038.
Abstract | Links | BibTeX | Tags: CeFO related, Optical design
@conference{Xiong2023b,
title = {Efficient all-dielectric metasurface in-coupler for waveguide-based near-eye display},
author = {Xiong, P., J. Goodsell, D.K. Nikolov, J.P. Rolland, and A.N Vamivakas},
editor = {Kress, Bernard C; Peroz, Christophe},
doi = {doi.org/10.1117/12.2646494},
isbn = {9781510660038},
year = {2023},
date = {2023-03-16},
urldate = {2023-03-16},
pages = {3},
publisher = {SPIE},
address = {San Fransisco, CA, USA},
abstract = {The creation of new see-through near-eye displays (NEDs) architectures is a topic of intense research focus. A fundamental problem that each design must address is the field of view (FOV) and eyebox of NEDs are limited by etendue conservation for a fixed display optics size. Waveguide architecture provides the solution to increasing the eyebox in NEDs without increasing the optics size through exit pupil expansion. Brightness and uniformity are two key features of waveguide architecture. In this work, we focus on the brightness of the waveguide since the image uniformity can be compensated by the display engine. We show that the geometry of the waveguide sets a fundamental limit on the in-coupling efficiency for a given FOV. This limit can be used as a tool for waveguide designers to benchmark the in-coupling efficiency of their incoupler gratings. With this derived limit, we designed and optimized a metasurface-based grating (metagrating) and a surface relief grating (SRG) as in-couplers. The diffractive efficiencies of the two types of in-couplers were then compared to the theoretical efficiency limit. The metagrating's 28% efficiency surpasses the SRG's 20% efficiency and nearly matches the geometry-based limit of 29% due to the superior angular response control of metasurfaces compared to SRGs. This work provides a new understanding of the brightness efficiency limit of waveguide-based combiners and paves a novel path toward implementing metasurfaces in efficient waveguide AR displays.},
keywords = {CeFO related, Optical design},
pubstate = {published},
tppubtype = {conference}
}
The creation of new see-through near-eye displays (NEDs) architectures is a topic of intense research focus. A fundamental problem that each design must address is the field of view (FOV) and eyebox of NEDs are limited by etendue conservation for a fixed display optics size. Waveguide architecture provides the solution to increasing the eyebox in NEDs without increasing the optics size through exit pupil expansion. Brightness and uniformity are two key features of waveguide architecture. In this work, we focus on the brightness of the waveguide since the image uniformity can be compensated by the display engine. We show that the geometry of the waveguide sets a fundamental limit on the in-coupling efficiency for a given FOV. This limit can be used as a tool for waveguide designers to benchmark the in-coupling efficiency of their incoupler gratings. With this derived limit, we designed and optimized a metasurface-based grating (metagrating) and a surface relief grating (SRG) as in-couplers. The diffractive efficiencies of the two types of in-couplers were then compared to the theoretical efficiency limit. The metagrating's 28% efficiency surpasses the SRG's 20% efficiency and nearly matches the geometry-based limit of 29% due to the superior angular response control of metasurfaces compared to SRGs. This work provides a new understanding of the brightness efficiency limit of waveguide-based combiners and paves a novel path toward implementing metasurfaces in efficient waveguide AR displays.
Y Fan, D. K. Nikolov; Rolland, J. P.
Freeform Manufacturing Process Optimized by Automatically Generated CAD Model Conference
SPIE, 2023.
Abstract | Links | BibTeX | Tags: CeFO related, fabrication
@conference{Fan2023,
title = {Freeform Manufacturing Process Optimized by Automatically Generated CAD Model},
author = {Fan, Y, D.K. Nikolov, M. Pomerantz, A.N. Vamivakas, and J.P. Rolland},
doi = {10.1117/12.2647769},
year = {2023},
date = {2023-03-16},
urldate = {2023-03-16},
publisher = {SPIE},
abstract = {Metaforms are novel optical components formed by conforming a metasurface to a freeform substrate. Metaforms can be a powerful solution when designing compact imaging systems such as augmented reality displays. Given the rotationally variant nature of the metaform substrate and the difficulty of metasurface fabrication on curved substrates, the proper alignment of the metasurface nanofeatures to the freeform substrate is essential. Thus, to seamlessly bridge the metaform design, manufacturing, and metrology, we developed a software tool that automatically generates ISO standard highaccuracy CAD models for the designed metaform components},
keywords = {CeFO related, fabrication},
pubstate = {published},
tppubtype = {conference}
}
Metaforms are novel optical components formed by conforming a metasurface to a freeform substrate. Metaforms can be a powerful solution when designing compact imaging systems such as augmented reality displays. Given the rotationally variant nature of the metaform substrate and the difficulty of metasurface fabrication on curved substrates, the proper alignment of the metasurface nanofeatures to the freeform substrate is essential. Thus, to seamlessly bridge the metaform design, manufacturing, and metrology, we developed a software tool that automatically generates ISO standard highaccuracy CAD models for the designed metaform components
Goodsell, J.; Xiong, P.; Nikolov, D. K.; Vamivakas, A. N.; Rolland, J. P.
Metagrating meets the geometry-based efficiency limit for AR waveguide in-couplers Journal Article
In: Optics Express, vol. 31, iss. 3, pp. 4599-4614, 2023.
Abstract | Links | BibTeX | Tags: CeFO related, design
@article{Goodsell2023,
title = {Metagrating meets the geometry-based efficiency limit for AR waveguide in-couplers},
author = {J. Goodsell and P. Xiong and D. K. Nikolov and A. N. Vamivakas and J. P. Rolland},
doi = {https://doi.org/10.1364/OE.480092},
year = {2023},
date = {2023-01-24},
urldate = {2023-01-24},
journal = {Optics Express},
volume = {31},
issue = {3},
pages = {4599-4614},
abstract = {Recently, augmented reality (AR) displays have attracted considerable attention due to the highly immersive and realistic viewer experience they can provide. One key challenge of AR displays is the fundamental trade-off between the extent of the field-of-view (FOV) and the size of the eyebox, set by the conservation of etendue sets this trade-off. Exit-pupil expansion (EPE) is one possible solution to this problem. However, it comes at the cost of distributing light over a larger area, decreasing the overall system's brightness. In this work, we show that the geometry of the waveguide and the in-coupler sets a fundamental limit on how efficient the combiner can be for a given FOV. This limit can be used as a tool for waveguide designers to benchmark the in-coupling efficiency of their in-coupler gratings. We design a metasurface-based grating (metagrating) and a commonly used SRG as in-couplers using the derived limit to guide optimization. We then compare the diffractive efficiencies of the two types of in-couplers to the theoretical efficiency limit. For our chosen waveguide geometry, the metagrating's 28% efficiency surpasses the SRG's 20% efficiency and nearly matches the geometry-based limit of 29% due to the superior angular response control of metasurfaces compared to SRGs. This work provides new insight into the efficiency limit of waveguide-based combiners and paves a novel path toward implementing metasurfaces in efficient waveguide AR displays.},
keywords = {CeFO related, design},
pubstate = {published},
tppubtype = {article}
}
Recently, augmented reality (AR) displays have attracted considerable attention due to the highly immersive and realistic viewer experience they can provide. One key challenge of AR displays is the fundamental trade-off between the extent of the field-of-view (FOV) and the size of the eyebox, set by the conservation of etendue sets this trade-off. Exit-pupil expansion (EPE) is one possible solution to this problem. However, it comes at the cost of distributing light over a larger area, decreasing the overall system's brightness. In this work, we show that the geometry of the waveguide and the in-coupler sets a fundamental limit on how efficient the combiner can be for a given FOV. This limit can be used as a tool for waveguide designers to benchmark the in-coupling efficiency of their in-coupler gratings. We design a metasurface-based grating (metagrating) and a commonly used SRG as in-couplers using the derived limit to guide optimization. We then compare the diffractive efficiencies of the two types of in-couplers to the theoretical efficiency limit. For our chosen waveguide geometry, the metagrating's 28% efficiency surpasses the SRG's 20% efficiency and nearly matches the geometry-based limit of 29% due to the superior angular response control of metasurfaces compared to SRGs. This work provides new insight into the efficiency limit of waveguide-based combiners and paves a novel path toward implementing metasurfaces in efficient waveguide AR displays.
2022
Buralli, D.
Freeform Optics for AR/VR Glasses, Metasurfaces and Metaforms Online
2022.
Links | BibTeX | Tags: CeFO related
@online{AOS_2022,
title = {Freeform Optics for AR/VR Glasses, Metasurfaces and Metaforms},
author = {D. Buralli},
url = {https://www.apollooptical.com/freeform-optics-for-ar-vr-glasses-metasurfaces-metaforms/},
year = {2022},
date = {2022-12-15},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {online}
}
Steidle, J.; Zuraski, S.; Rolland, J. P.
Effects of Sub-Aperture Pupil Aberrations for Sparse Aperture Coherent Phasing Presentation
15.11.2022.
Abstract | BibTeX | Tags: CeFO related
@misc{steidle_2022_MTD,
title = {Effects of Sub-Aperture Pupil Aberrations for Sparse Aperture Coherent Phasing},
author = {J. Steidle and S. Zuraski and J. P. Rolland},
year = {2022},
date = {2022-11-15},
abstract = {2022 Mirror Technology Days},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {presentation}
}
2022 Mirror Technology Days
Rolland, J. P.
Shaping the future with freeform optics and metaform Presentation
28.10.2022.
Abstract | BibTeX | Tags: CeFO related
@misc{rolland_IMT_2022,
title = {Shaping the future with freeform optics and metaform},
author = {J. P. Rolland},
year = {2022},
date = {2022-10-28},
abstract = {IMT Atlantique, France},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {presentation}
}
IMT Atlantique, France
Sullivan, Frost
Imprinting Nanostructures on Freeform Optics for High Quality Imagery and Compact Design In AR/VR Glasses Technical Report
2022.
BibTeX | Tags: CeFO related
@techreport{frost_sullivan_2022,
title = {Imprinting Nanostructures on Freeform Optics for High Quality Imagery and Compact Design In AR/VR Glasses},
author = {Frost Sullivan},
year = {2022},
date = {2022-08-15},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {techreport}
}
Shanmugam, Prithiviraj; Lambropoulos, John C.; Matthew A, Davies
Grinding of silicon carbide for optical surface fabrication, Part 1: surface analysis Journal Article
In: Applied Optics, vol. 61, iss. 15, pp. 4579-4590, 2022.
@article{Davies2022,
title = {Grinding of silicon carbide for optical surface fabrication, Part 1: surface analysis},
author = {Prithiviraj Shanmugam and John C. Lambropoulos and Matthew A, Davies},
year = {2022},
date = {2022-06-01},
urldate = {2022-06-01},
journal = {Applied Optics},
volume = {61},
issue = {15},
pages = {4579-4590},
abstract = {This paper presents a study of the grinding of three different grades of silicon carbide (SiC) under the same conditions. Surface topography is analyzed using coherent scanning interferometry and scanning electron microscopy. The study provides a baseline understanding of the process mechanics and targets effective selection of process parameters for grinding SiC optics with near optical level surface roughness, thus reducing the need for post-polishing. Samples are raster and spiral ground on conventional precision machines with metal and copper-resin bonded wheels under rough, medium, and finish grinding conditions. Material microstructure and grinding conditions affect attainable surface roughness. Local surface roughness of less than 3 nm RMS was attained in both chemical vapor deposition (CVD) and chemical vapor composite (CVC) SiC. The tool footprint is suitable for sub-aperture machining of a large freeform optics possibly without the need for surface finish correction by post-polishing. Subsurface damage will be assessed in Part 2 of this paper series.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This paper presents a study of the grinding of three different grades of silicon carbide (SiC) under the same conditions. Surface topography is analyzed using coherent scanning interferometry and scanning electron microscopy. The study provides a baseline understanding of the process mechanics and targets effective selection of process parameters for grinding SiC optics with near optical level surface roughness, thus reducing the need for post-polishing. Samples are raster and spiral ground on conventional precision machines with metal and copper-resin bonded wheels under rough, medium, and finish grinding conditions. Material microstructure and grinding conditions affect attainable surface roughness. Local surface roughness of less than 3 nm RMS was attained in both chemical vapor deposition (CVD) and chemical vapor composite (CVC) SiC. The tool footprint is suitable for sub-aperture machining of a large freeform optics possibly without the need for surface finish correction by post-polishing. Subsurface damage will be assessed in Part 2 of this paper series.
Goodsell, J.; Blahnik, V.; Rolland, J. P.
Method for minimizing lens breathing with one moving group Journal Article
In: Optics Express, vol. 30, iss. 11, pp. 19494-19509, 2022.
Abstract | Links | BibTeX | Tags:
@article{goodsell_2022,
title = {Method for minimizing lens breathing with one moving group},
author = {J. Goodsell and V. Blahnik and J. P. Rolland},
doi = {https://doi.org/10.1364/OE.457420},
year = {2022},
date = {2022-05-23},
journal = {Optics Express},
volume = {30},
issue = {11},
pages = {19494-19509},
abstract = {Lens breathing in movie cameras is the change in the overall content of a scene while bringing subjects located at different depths into focus. This paper presents a method for minimizing lens breathing or changing angular field-of-view while maintaining perspective by moving only one lens group. To maintain perspective, the stop is placed in a fixed position where no elements between the scene and the stop can move, thus fixing the entrance pupil in one location relative to the object fields. The result is perspective invariance while refocusing the lens. Using paraxial optics, we solve for the moving group's position to focus on every object position and eliminate breathing between the minimum and maximum object distances. We investigate the solution space for optical systems with two positive groups or a positive and a negative group (i.e., retrofocus and telephoto systems). We explain how to apply this paraxial solution to existing systems to minimize breathing. The results for two systems altered using this method are presented. Breathing improved by two orders of magnitude in both cases, and performance specifications were still met when compared to the initial systems.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Lens breathing in movie cameras is the change in the overall content of a scene while bringing subjects located at different depths into focus. This paper presents a method for minimizing lens breathing or changing angular field-of-view while maintaining perspective by moving only one lens group. To maintain perspective, the stop is placed in a fixed position where no elements between the scene and the stop can move, thus fixing the entrance pupil in one location relative to the object fields. The result is perspective invariance while refocusing the lens. Using paraxial optics, we solve for the moving group's position to focus on every object position and eliminate breathing between the minimum and maximum object distances. We investigate the solution space for optical systems with two positive groups or a positive and a negative group (i.e., retrofocus and telephoto systems). We explain how to apply this paraxial solution to existing systems to minimize breathing. The results for two systems altered using this method are presented. Breathing improved by two orders of magnitude in both cases, and performance specifications were still met when compared to the initial systems.
Briefs, Tech (Ed.)
New Optical Component Used to Create AR/VR Headsets and Eyewear Online
Briefs, Tech (Ed.): 2022.
Links | BibTeX | Tags: CeFO related
@online{techBrief_22,
title = {New Optical Component Used to Create AR/VR Headsets and Eyewear},
editor = {Tech Briefs},
url = {https://www.techbriefs.com/component/content/article/tb/pub/briefs/photonics-optics/45762},
year = {2022},
date = {2022-05-01},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {online}
}
Koerber, J.; Boreman, G. D.; Suleski, T. J.
Reduction of retrace error from broadband variable transmission spheres in Fizeau interferometry Journal Article
In: Optics Continuum, vol. 1, no. 5, pp. 1067-1076, 2022.
Links | BibTeX | Tags: CeFO related, metrology
@article{Koerber22b,
title = {Reduction of retrace error from broadband variable transmission spheres in Fizeau interferometry},
author = {J. Koerber and G.D. Boreman and T.J. Suleski},
doi = {https://doi.org/10.1364/OPTCON.458860},
year = {2022},
date = {2022-04-25},
journal = {Optics Continuum},
volume = {1},
number = {5},
pages = {1067-1076},
keywords = {CeFO related, metrology},
pubstate = {published},
tppubtype = {article}
}
Blackman, G.
Scaling challenges of metasurfaces Online
Optics, Electo (Ed.): 2022.
Links | BibTeX | Tags: CeFO related
@online{electro_optics22,
title = {Scaling challenges of metasurfaces},
author = {G. Blackman},
editor = {Electo Optics},
url = {https://www.electrooptics.com/feature/scaling-challenges-metasurfaces},
year = {2022},
date = {2022-04-15},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {online}
}
Rolland, J. P.; Vamivakas, N.; Kitt, A.; Bauer, A.
Freeform nanostructured surface for virtual and augmented reality near eye display Patent
2022.
BibTeX | Tags: CeFO related
@patent{rolland_pat_2022,
title = {Freeform nanostructured surface for virtual and augmented reality near eye display},
author = {J. P. Rolland and N. Vamivakas and A. Kitt and A. Bauer},
year = {2022},
date = {2022-04-05},
issue = {EP 3278169},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {patent}
}
Karci, O.; Yesiltepe, M.; Arpa, E.; Wu, Y.; Ekinci, M.; Rolland, J. P.
Experimental investigation in nodal aberration theory (NAT): separation of astigmatic figure error from misalignments in a Cassegrain telescope Journal Article
In: Optics Express, vol. 30, iss. 7, pp. 11150-11164, 2022.
Abstract | Links | BibTeX | Tags: CeFO related
@article{karci_2022,
title = {Experimental investigation in nodal aberration theory (NAT): separation of astigmatic figure error from misalignments in a Cassegrain telescope},
author = {O. Karci and M. Yesiltepe and E. Arpa and Y. Wu and M. Ekinci and J. P. Rolland},
doi = {https://doi.org/10.1364/OE.453788},
year = {2022},
date = {2022-03-28},
journal = {Optics Express},
volume = {30},
issue = {7},
pages = {11150-11164},
abstract = {We present simulations and experimental validations for separating astigmatic figure error from misalignments in Nodal Aberration Theory (NAT) with a high-precision Cassegrain telescope. Both the primary mirror figure error and the secondary mirror misalignments induce binodal astigmatism for the telescope systems. The separation of these two aberration factors plays a crucial role in the telescope alignment process. In this study, the figure error of the aspheric primary mirror of the Cassegrain telescope induced by the mirror mounts was measured interferometrically utilizing a computer-generated hologram (CGH). According to the primary mirror figure error, the astigmatic node locations in the image plane were simulated using real raytracing. The center of the nodes was located on the field center, and the nodes were placed symmetrically with respect to the field center in the image plane. The telescope's alignment was performed using the simulation results, and the node locations were measured on a grid of field points interferometrically. Thereafter, secondary mirror misalignments around the coma-free pivot point were introduced into the optical system, and the node's center was shifted from the field center in the image plane as predicted by NAT. The simulations and interferometric field measurements were performed and compared on a grid of field points for the misaligned state in the presence of primary mirror figure error. The experimental results confirm the predictions from NAT. Statistical analysis was also performed to confirm the accuracy and stability of the measurements.},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {article}
}
We present simulations and experimental validations for separating astigmatic figure error from misalignments in Nodal Aberration Theory (NAT) with a high-precision Cassegrain telescope. Both the primary mirror figure error and the secondary mirror misalignments induce binodal astigmatism for the telescope systems. The separation of these two aberration factors plays a crucial role in the telescope alignment process. In this study, the figure error of the aspheric primary mirror of the Cassegrain telescope induced by the mirror mounts was measured interferometrically utilizing a computer-generated hologram (CGH). According to the primary mirror figure error, the astigmatic node locations in the image plane were simulated using real raytracing. The center of the nodes was located on the field center, and the nodes were placed symmetrically with respect to the field center in the image plane. The telescope's alignment was performed using the simulation results, and the node locations were measured on a grid of field points interferometrically. Thereafter, secondary mirror misalignments around the coma-free pivot point were introduced into the optical system, and the node's center was shifted from the field center in the image plane as predicted by NAT. The simulations and interferometric field measurements were performed and compared on a grid of field points for the misaligned state in the presence of primary mirror figure error. The experimental results confirm the predictions from NAT. Statistical analysis was also performed to confirm the accuracy and stability of the measurements.
Koerber, J.; Boreman, G. D.; Suleski, T. J.
Broadband Variable Transmission Sphere for Fizeau Interferometry Journal Article
In: Optics, vol. 3, pp. 88-98, 2022.
Links | BibTeX | Tags: CeFO related, metrology
@article{Koerber22a,
title = {Broadband Variable Transmission Sphere for Fizeau Interferometry},
author = {J. Koerber and G.D. Boreman and T.J. Suleski},
doi = {https://doi.org/10.3390/opt3010011},
year = {2022},
date = {2022-03-10},
journal = {Optics},
volume = {3},
pages = {88-98},
keywords = {CeFO related, metrology},
pubstate = {published},
tppubtype = {article}
}
Falaggis, K.; Rolland, J. P.; Duerr, F.; Sohn, A.
Freeform Optics: Introduction Journal Article
In: Optics Express, vol. 30, iss. 4, pp. 6450-6455, 2022.
Abstract | Links | BibTeX | Tags: CeFO related
@article{falaggis_2022,
title = {Freeform Optics: Introduction},
author = {K. Falaggis and J. P. Rolland and F. Duerr and A. Sohn},
doi = {https://doi.org/10.1364/OE.454788},
year = {2022},
date = {2022-02-14},
journal = {Optics Express},
volume = {30},
issue = {4},
pages = {6450-6455},
abstract = {This feature issue of Optics Express highlights 28 state-of-the-art articles that capture a snapshot of the recent developments in the field of freeform optics. As an introduction, the editors provide an overview of all published articles, which cover a broad range of topics in freeform optics. The wide variety of applications presented here demonstrates that freeform optics is a growing and vibrant field with many more innovations to come.},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {article}
}
This feature issue of Optics Express highlights 28 state-of-the-art articles that capture a snapshot of the recent developments in the field of freeform optics. As an introduction, the editors provide an overview of all published articles, which cover a broad range of topics in freeform optics. The wide variety of applications presented here demonstrates that freeform optics is a growing and vibrant field with many more innovations to come.
Takaki, N.; Forbes, G. W.; Rolland, J. P.
Schemes for cubature over the unit disk found via numerical optimization Journal Article
In: Journal of Computational and Applied Mathematics, vol. 407, pp. 114076, 2022, ISBN: 0377-0427.
Abstract | Links | BibTeX | Tags: CeFO related
@article{takaki_cub2022,
title = {Schemes for cubature over the unit disk found via numerical optimization},
author = {N. Takaki and G. W. Forbes and J.P. Rolland},
doi = {https://doi.org/10.1016/j.cam.2021.114076},
isbn = {0377-0427},
year = {2022},
date = {2022-01-03},
journal = {Journal of Computational and Applied Mathematics},
volume = {407},
pages = {114076},
abstract = {Cubature schemes, in this case for uniformly weighted integration over the unit disk, enable exact evaluation of numerical integrals of polynomials but have been explicitly constructed for only low or moderate degrees. In this paper, cubature formulae are discovered for a wider range of degrees by leveraging numerical optimization. These results include a degree-17 cubature scheme with fewer points than existing solutions and up to a degree-77 solution with 1021 cubature points. Optimization heuristics and patterns in the distributions of cubature points are discussed, which serve as vital guides in this work. For example, these heuristics leverage a connection to circle-packing configurations to facilitate the discovery of fully symmetric cubature schemes.},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {article}
}
Cubature schemes, in this case for uniformly weighted integration over the unit disk, enable exact evaluation of numerical integrals of polynomials but have been explicitly constructed for only low or moderate degrees. In this paper, cubature formulae are discovered for a wider range of degrees by leveraging numerical optimization. These results include a degree-17 cubature scheme with fewer points than existing solutions and up to a degree-77 solution with 1021 cubature points. Optimization heuristics and patterns in the distributions of cubature points are discussed, which serve as vital guides in this work. For example, these heuristics leverage a connection to circle-packing configurations to facilitate the discovery of fully symmetric cubature schemes.
2021
Hu, W.; Kilinc, M.; Gebremichael, W.; C. Dorrer,; Qiao, J.
Morphology and waveguiding properties of ultrafast-laser-inscribed type-II waveguides in IG2 Journal Article
In: Optical Materials Express, vol. 12, no. 1, pp. 360-373, 2021.
Abstract | Links | BibTeX | Tags: manufacturing, related
@article{Hu2021,
title = {Morphology and waveguiding properties of ultrafast-laser-inscribed type-II waveguides in IG2},
author = {W. Hu and M. Kilinc and W. Gebremichael and C. Dorrer, and J. Qiao},
url = {https://opg.optica.org/ome/fulltext.cfm?uri=ome-12-1-360&id=466364},
year = {2021},
date = {2021-12-24},
urldate = {2021-12-24},
journal = {Optical Materials Express},
volume = {12},
number = {1},
pages = {360-373},
abstract = {Ultrafast-laser-inscribed type-II waveguides inside the chalcogenide glass IG2 and the morphology of the inscribed tracks are presented for the first time to our knowledge. Self-organized periodic structures induced by the ultrafast laser in the tracks are characterized. The near-infrared waveguiding properties are studied for various pulse energies, durations, repetition rates, and polarization states, as well as different separations between the two written tracks. A propagation loss of ∼ 2.3 dB/cm is demonstrated in a type-II waveguide formed in IG2.},
keywords = {manufacturing, related},
pubstate = {published},
tppubtype = {article}
}
Ultrafast-laser-inscribed type-II waveguides inside the chalcogenide glass IG2 and the morphology of the inscribed tracks are presented for the first time to our knowledge. Self-organized periodic structures induced by the ultrafast laser in the tracks are characterized. The near-infrared waveguiding properties are studied for various pulse energies, durations, repetition rates, and polarization states, as well as different separations between the two written tracks. A propagation loss of ∼ 2.3 dB/cm is demonstrated in a type-II waveguide formed in IG2.
Feng, T.; Chen, G.; Han, H.; Qiao, J.
Femtosecond-Laser-Ablation Dynamics in Silicon Revealed by Transient Reflectivity Change Journal Article
In: Micromachines, vol. 13, no. 1, 2021.
Abstract | Links | BibTeX | Tags: manufacturing, related
@article{Feng2021,
title = {Femtosecond-Laser-Ablation Dynamics in Silicon Revealed by Transient Reflectivity Change},
author = {T. Feng and G. Chen and H. Han and J. Qiao},
url = {https://www.mdpi.com/2072-666X/13/1/14#
https://centerfreeformoptics.org/wp-content/uploads/2023/02/micromachines-13-00014-v2.pdf},
doi = {https://doi.org/10.3390/mi13010014},
year = {2021},
date = {2021-12-23},
urldate = {2021-12-23},
journal = {Micromachines},
volume = {13},
number = {1},
abstract = {The dynamics of ablation in monocrystalline silicon, from electron-hole plasma generation to material expansion, upon irradiation by a single femtosecond laser pulse (1030 nm, 300 fs pulse duration) at a wide range of fluences is investigated using a time-resolved microscopy technique. The reflectivity evolution obtained from dynamic images in combination with a theoretical Drude model and a Two-Temperature model provides new insights on material excitation and ablation process. For all fluences, the reflectivity increased to a temporary stable state after hundreds of femtoseconds. This behavior was predicted using a temperature-dependent refractive index in the Drude model. The increase in velocity of plasma generation with increasing fluence was theoretically predicted by the Two-Temperature model. Two ablation regimes at high fluences (>0.86 J/cm2) were identified through the measured transient reflectivity and ablation crater profile. The simulation shows that the fluence triggering the second ablation regime produces a boiling temperature (silicon, 2628 K).},
keywords = {manufacturing, related},
pubstate = {published},
tppubtype = {article}
}
The dynamics of ablation in monocrystalline silicon, from electron-hole plasma generation to material expansion, upon irradiation by a single femtosecond laser pulse (1030 nm, 300 fs pulse duration) at a wide range of fluences is investigated using a time-resolved microscopy technique. The reflectivity evolution obtained from dynamic images in combination with a theoretical Drude model and a Two-Temperature model provides new insights on material excitation and ablation process. For all fluences, the reflectivity increased to a temporary stable state after hundreds of femtoseconds. This behavior was predicted using a temperature-dependent refractive index in the Drude model. The increase in velocity of plasma generation with increasing fluence was theoretically predicted by the Two-Temperature model. Two ablation regimes at high fluences (>0.86 J/cm2) were identified through the measured transient reflectivity and ablation crater profile. The simulation shows that the fluence triggering the second ablation regime produces a boiling temperature (silicon, 2628 K).
Rolland, J. P.
Freeform Optics for Imaging and the Concept of the Metaform Presentation
1st International Conference Advances in 3OM: Opto-Mechatronics, Optomechanics, and Optical Metrology, 13.12.2021.
BibTeX | Tags: CeFO related
@misc{rolland_romania21,
title = {Freeform Optics for Imaging and the Concept of the Metaform},
author = {J. P. Rolland},
year = {2021},
date = {2021-12-13},
urldate = {2021-12-13},
howpublished = {1st International Conference Advances in 3OM: Opto-Mechatronics, Optomechanics, and Optical Metrology},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {presentation}
}
Papa, J. C.; Howard, J. M.; Rolland, J. P.
Survey of the four-mirror freeform imager solution space Journal Article
In: Optics Express, vol. 29, iss. 25, pp. 41534-41551, 2021.
Abstract | Links | BibTeX | Tags: CeFO related
@article{papa_OE21,
title = {Survey of the four-mirror freeform imager solution space},
author = {J. C. Papa and J. M. Howard and J. P. Rolland},
doi = {https://doi.org/10.1364/OE.442943},
year = {2021},
date = {2021-12-06},
journal = {Optics Express},
volume = {29},
issue = {25},
pages = {41534-41551},
abstract = {We present the results and methods of a survey of the four-mirror freeform imager solution space. This survey is a grid search over the parameters that remain after reducing the solution space’s degrees of freedom using first-, second-, and third-order aberration theory. We then optimize the systems’ higher-order surface shapes through sixth-order. Finally, we discuss general trends in the systems’ performance versus volume and etendue and their utility in trade studies.},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {article}
}
We present the results and methods of a survey of the four-mirror freeform imager solution space. This survey is a grid search over the parameters that remain after reducing the solution space’s degrees of freedom using first-, second-, and third-order aberration theory. We then optimize the systems’ higher-order surface shapes through sixth-order. Finally, we discuss general trends in the systems’ performance versus volume and etendue and their utility in trade studies.
(Ed.)
Metaform Optics Periodical
2021.
BibTeX | Tags: CeFO related
@periodical{nikolov_OPN,
title = {Metaform Optics},
author = {D. K. Nikolov and A. Bauer and N. Vamivakas and J. P. Rolland},
year = {2021},
date = {2021-12-02},
howpublished = {Optics in 2021 - Optics and Photonics News },
keywords = {CeFO related},
pubstate = {published},
tppubtype = {periodical}
}
Rolland, J. P.; Bauer, A.; Yates, D.; Farsad, M.
Compact Freeform Echelle Spectrometer (US Patent 11,169,024 B2) Patent
2021.
BibTeX | Tags: CeFO related
@patent{PE_patent21,
title = {Compact Freeform Echelle Spectrometer (US Patent 11,169,024 B2)},
author = {J. P. Rolland and A. Bauer and D. Yates and M. Farsad},
year = {2021},
date = {2021-11-09},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {patent}
}
Swain, BR; Dorrer, C.; Qiao, J.
Telephoto-lens-based Optical Differentiation Wavefront Sensor for freeform metrology Journal Article
In: Opt. Express, vol. 29, no. 23, pp. 38395-38403, 2021.
Abstract | Links | BibTeX | Tags: metrology, related
@article{Swain2021,
title = {Telephoto-lens-based Optical Differentiation Wavefront Sensor for freeform metrology},
author = {BR Swain and C. Dorrer and J. Qiao},
url = {https://opg.optica.org/oe/fulltext.cfm?uri=oe-29-23-38395&id=464483},
doi = {https://doi.org/10.1364/OE.443558},
year = {2021},
date = {2021-11-03},
urldate = {2021-11-03},
journal = {Opt. Express},
volume = {29},
number = {23},
pages = {38395-38403},
abstract = {We report an Optical Differentiation Wavefront Sensor based on a telephoto lens system and binary pixelated filters. It provides a five-fold reduction in the system length compared to a 4f system with identical effective focal length. Measurements of phase plates with this system are compared to measurements performed with a commercial low-coherence interferometer. The telephoto-lens-based system can measure wavefronts with accuracy better than λ/10 Root Mean Squared (RMS) at λ=633 nm. Experimental investigation shows that the system has a high tolerance to components alignment errors.},
keywords = {metrology, related},
pubstate = {published},
tppubtype = {article}
}
We report an Optical Differentiation Wavefront Sensor based on a telephoto lens system and binary pixelated filters. It provides a five-fold reduction in the system length compared to a 4f system with identical effective focal length. Measurements of phase plates with this system are compared to measurements performed with a commercial low-coherence interferometer. The telephoto-lens-based system can measure wavefronts with accuracy better than λ/10 Root Mean Squared (RMS) at λ=633 nm. Experimental investigation shows that the system has a high tolerance to components alignment errors.
Rolland, J. P.
Freeform Optics for Imaging & Metaform Optics in Near-Eye Displays Presentation
Stanford Center for Image Systems Engineering, 03.11.2021.
Links | BibTeX | Tags: CeFO related
@misc{rolland_stanford21,
title = {Freeform Optics for Imaging & Metaform Optics in Near-Eye Displays},
author = {J. P. Rolland},
url = {https://ee-archive.stanford.edu/event/seminar/scien-presents-freeform-optics-imaging-and-metaform-optics-near-eye-displays},
year = {2021},
date = {2021-11-03},
urldate = {2021-11-03},
howpublished = {Stanford Center for Image Systems Engineering},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {presentation}
}
Nikolov, D. K; Bauer, A.; Vamivakas, A. N.; Rolland, J. P.
From Freeform to Metaform: Design, Fabrication, and Testing Proceedings
Proc. SPIE 11889, Optifab 2021, 1188903, 2021.
Abstract | Links | BibTeX | Tags: CeFO related
@proceedings{nikolov_optifab21,
title = {From Freeform to Metaform: Design, Fabrication, and Testing},
author = {D. K Nikolov and A. Bauer and A. N. Vamivakas and J. P. Rolland},
doi = {https://doi.org/10.1117/12.2613107},
year = {2021},
date = {2021-11-01},
urldate = {2021-11-01},
issue = {Proc. SPIE 11889, Optifab 2021, 1188903},
abstract = {Freeform optics and metasurfaces are two emerging optical technologies that show promise for addressing the needs of modern consumer devices like augmented and virtual reality (AR/VR) displays and mobile cameras. Recent advances in fabrication and testing have been critical to the success of freeform optics. In parallel, various methods for metasurface fabrication, including electron-beam lithography (EBL), have been researched and well established in the last decade but have been limited to fabrication on flat substrates. Metaform is a new optical component that consists of a metasurface conformed to a freeform substrate. We will explore the advances in nodal aberration theory, freeform design methodology, nanofabrication, and metrology necessary to make metaform optics a reality. To validate the developed processes and highlight the advantages of metaforms, we will examine a compact metaform imager inspired by the needs of AR displays. By leveraging the benefits of both metasurfaces and freeform optics, metaforms can thus be used to navigate critical design tradeoffs between optical performance, system volume, and form factor.},
howpublished = {Proc. SPIE 11889, Optifab 2021, 1188903},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {proceedings}
}
Freeform optics and metasurfaces are two emerging optical technologies that show promise for addressing the needs of modern consumer devices like augmented and virtual reality (AR/VR) displays and mobile cameras. Recent advances in fabrication and testing have been critical to the success of freeform optics. In parallel, various methods for metasurface fabrication, including electron-beam lithography (EBL), have been researched and well established in the last decade but have been limited to fabrication on flat substrates. Metaform is a new optical component that consists of a metasurface conformed to a freeform substrate. We will explore the advances in nodal aberration theory, freeform design methodology, nanofabrication, and metrology necessary to make metaform optics a reality. To validate the developed processes and highlight the advantages of metaforms, we will examine a compact metaform imager inspired by the needs of AR displays. By leveraging the benefits of both metasurfaces and freeform optics, metaforms can thus be used to navigate critical design tradeoffs between optical performance, system volume, and form factor.
Rolland, J. P.; Nikolov, D. K.; Bauer, A.; Vamivakas, A. N.
AR Technology Drives the Emergence of the Metaform Presentation
Frontiers in Optics and Laser Science (FIO LS 2021) , 01.11.2021.
BibTeX | Tags: CeFO related
@misc{rolland_FIO21,
title = {AR Technology Drives the Emergence of the Metaform},
author = {J. P. Rolland and D. K. Nikolov and A. Bauer and A. N. Vamivakas},
year = {2021},
date = {2021-11-01},
howpublished = {Frontiers in Optics and Laser Science (FIO LS 2021) },
keywords = {CeFO related},
pubstate = {published},
tppubtype = {presentation}
}
Koerber, Jonathan; Suleski, Thomas J.
Broadband Variable Transmission Sphere for Fizeau Interferometry of Spherical Surfaces Proceedings
2021, ISBN: ISBN: 978-1-943580-88-0.
Abstract | Links | BibTeX | Tags: CeFO related
@proceedings{Koerber_1,
title = {Broadband Variable Transmission Sphere for Fizeau Interferometry of Spherical Surfaces},
author = {Jonathan Koerber and Thomas J. Suleski},
url = {https://doi.org/10.1364/OFT.2021.OW3B.6},
doi = {https://doi.org/10.1364/OFT.2021.OW3B.6},
isbn = {ISBN: 978-1-943580-88-0},
year = {2021},
date = {2021-07-01},
urldate = {2021-07-01},
abstract = {We present a broadband variable transmission sphere for Fizeau interferometry based on Alvarez lenses. The simulated system performance is compared to conventional transmission spheres for measurement of spherical surfaces.},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {proceedings}
}
We present a broadband variable transmission sphere for Fizeau interferometry based on Alvarez lenses. The simulated system performance is compared to conventional transmission spheres for measurement of spherical surfaces.
Suleski, Thomas J.
Towards Conformally Nanostructured Freeform Optics Proceedings
2021, ISBN: ISBN: 978-1-943580-88-0.
Abstract | Links | BibTeX | Tags: CeFO related
@proceedings{Suleski_1,
title = {Towards Conformally Nanostructured Freeform Optics},
author = {Thomas J. Suleski},
url = {https://doi.org/10.1364/FLATOPTICS.2021.JW3D.1},
doi = {https://doi.org/10.1364/FLATOPTICS.2021.JW3D.1},
isbn = {ISBN: 978-1-943580-88-0},
year = {2021},
date = {2021-07-01},
urldate = {2021-07-01},
abstract = {Conformally nanostructured freeform optics can enable smaller systems and new or improved functionality but are limited by available manufacturing methods. To this end, I review experimental manufacturing approaches and example applications and discuss current fabrication challenges.},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {proceedings}
}
Conformally nanostructured freeform optics can enable smaller systems and new or improved functionality but are limited by available manufacturing methods. To this end, I review experimental manufacturing approaches and example applications and discuss current fabrication challenges.
Nikolov, D. K.; Bauer, A.; Vamivakas, N.; Rolland, J. P.
Metaform Optical Imager Presentation
OSA Optical Design and Fabrication Congress: Joint Flat Optics and Freeform, 30.06.2021.
BibTeX | Tags: CeFO related
@misc{nikolov_OSA_21,
title = {Metaform Optical Imager},
author = {D. K. Nikolov and A. Bauer and N. Vamivakas and J. P. Rolland},
year = {2021},
date = {2021-06-30},
howpublished = {OSA Optical Design and Fabrication Congress: Joint Flat Optics and Freeform},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {presentation}
}
DeMars, Luke A.; Suleski, Thomas J.
Separating and Estimating Impacts of Anisotropic Mid-Spatial Frequency Errors Proceedings
2021, ISBN: 978-1-943580-88-0.
Abstract | Links | BibTeX | Tags: manufacturing, Mid-Spatial Frequency error, related
@proceedings{DeMars2021,
title = {Separating and Estimating Impacts of Anisotropic Mid-Spatial Frequency Errors},
author = {Luke A. DeMars and Thomas J. Suleski },
editor = {OSA Technical Digest (Optica Publishing Group, 2021)},
doi = {10.1364/OFT.2021.OW3B.2},
isbn = {978-1-943580-88-0},
year = {2021},
date = {2021-06-30},
urldate = {2021-06-30},
abstract = {We present a methodology based on the areal power spectral density to separate and
estimate the impacts of multiple anisotropic mid-spatial frequency surface errors on optical
performance.},
keywords = {manufacturing, Mid-Spatial Frequency error, related},
pubstate = {published},
tppubtype = {proceedings}
}
We present a methodology based on the areal power spectral density to separate and
estimate the impacts of multiple anisotropic mid-spatial frequency surface errors on optical
performance.
estimate the impacts of multiple anisotropic mid-spatial frequency surface errors on optical
performance.
Papa, J. C.; Howard, J. M.; Rolland, J. P.
Survey of the Four-Mirror Freeform Imager Solution Space Presentation
OSA Optical Design and Fabrication Congress: Freeform , 29.06.2021.
BibTeX | Tags: CeFO related
@misc{papa_OSA_invited21,
title = {Survey of the Four-Mirror Freeform Imager Solution Space},
author = {J. C. Papa and J. M. Howard and J. P. Rolland},
year = {2021},
date = {2021-06-29},
howpublished = {OSA Optical Design and Fabrication Congress: Freeform },
keywords = {CeFO related},
pubstate = {published},
tppubtype = {presentation}
}
Qiao, Jie
Ultrafast Laser Enabled Optical Fabrication Proceedings
2021, ISBN: 978-1-943580-88-0.
Abstract | Links | BibTeX | Tags: manufacturing, related
@proceedings{Qiao2021,
title = {Ultrafast Laser Enabled Optical Fabrication},
author = {Jie Qiao},
url = {https://opg.optica.org/abstract.cfm?uri=oft-2021-OW4B.1&origin=search},
doi = {https://doi.org/10.1364/OFT.2021.OW4B.1},
isbn = {978-1-943580-88-0},
year = {2021},
date = {2021-06-27},
urldate = {2021-06-27},
abstract = {This paper presents methods, computational models, physical processes, and demonstrations related to femtosecond laser enabled polishing and micro-joining of optical and optomechanical components.},
keywords = {manufacturing, related},
pubstate = {published},
tppubtype = {proceedings}
}
This paper presents methods, computational models, physical processes, and demonstrations related to femtosecond laser enabled polishing and micro-joining of optical and optomechanical components.
Karci, O.; Arpa, E.; Ekinci, M.; Rolland, J. P.
Experimental investigation of binodal astigmatism in nodal aberration theory (NAT) with a Cassegrain telescope system Journal Article
In: Optics Express, vol. 29, iss. 13, pp. 19427-19440, 2021.
Abstract | Links | BibTeX | Tags: CeFO related
@article{karci_NAT21,
title = {Experimental investigation of binodal astigmatism in nodal aberration theory (NAT) with a Cassegrain telescope system},
author = {O. Karci and E. Arpa and M. Ekinci and J. P. Rolland},
doi = {https://doi.org/10.1364/OE.427164},
year = {2021},
date = {2021-06-21},
journal = {Optics Express},
volume = {29},
issue = {13},
pages = {19427-19440},
abstract = {We present simulations and an experimental investigation of binodal astigmatism in
nodal aberration theory (NAT) for a customized, high-precision Cassegrain telescope system. The
telescope system utilizes a five-axis, piezo-actuated flexural mechanism to introduce secondary
mirror misalignments and generate aberrations intentionally. The induced aberrations are
measured interferometrically and quantified for a grid of field points on the telescope system’s
image plane. For this purpose, a coma-free pivot point of the secondary mirror was simulated for
isolating the binodal astigmatism field response. The separation of the nodes is proportional to
the introduced misalignments. A simulation of Fringe Zernike coma and binodal astigmatism
was generated using a real ray trace model of the optical system and analyzed to compare to
the experimental results. A statistical analysis of the measurements was performed to show the
experimental results’ accuracy and stability. The experimental results were consistent with the
simulations, hence experimentally validating NAT for binodal astigmatism for the first time.
},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {article}
}
We present simulations and an experimental investigation of binodal astigmatism in
nodal aberration theory (NAT) for a customized, high-precision Cassegrain telescope system. The
telescope system utilizes a five-axis, piezo-actuated flexural mechanism to introduce secondary
mirror misalignments and generate aberrations intentionally. The induced aberrations are
measured interferometrically and quantified for a grid of field points on the telescope system’s
image plane. For this purpose, a coma-free pivot point of the secondary mirror was simulated for
isolating the binodal astigmatism field response. The separation of the nodes is proportional to
the introduced misalignments. A simulation of Fringe Zernike coma and binodal astigmatism
was generated using a real ray trace model of the optical system and analyzed to compare to
the experimental results. A statistical analysis of the measurements was performed to show the
experimental results’ accuracy and stability. The experimental results were consistent with the
simulations, hence experimentally validating NAT for binodal astigmatism for the first time.
nodal aberration theory (NAT) for a customized, high-precision Cassegrain telescope system. The
telescope system utilizes a five-axis, piezo-actuated flexural mechanism to introduce secondary
mirror misalignments and generate aberrations intentionally. The induced aberrations are
measured interferometrically and quantified for a grid of field points on the telescope system’s
image plane. For this purpose, a coma-free pivot point of the secondary mirror was simulated for
isolating the binodal astigmatism field response. The separation of the nodes is proportional to
the introduced misalignments. A simulation of Fringe Zernike coma and binodal astigmatism
was generated using a real ray trace model of the optical system and analyzed to compare to
the experimental results. A statistical analysis of the measurements was performed to show the
experimental results’ accuracy and stability. The experimental results were consistent with the
simulations, hence experimentally validating NAT for binodal astigmatism for the first time.
Rolland, J. P.; Vamivakas, N.; Kitt, A.; Bauer, A.
Freeform Nanostructured Surface for Virtual and Augmented Reality Near Eye Display (JPN Patent 6892827) Patent
2021.
BibTeX | Tags: CeFO related
@patent{hwd_patentJPN21,
title = {Freeform Nanostructured Surface for Virtual and Augmented Reality Near Eye Display (JPN Patent 6892827)},
author = {J. P. Rolland and N. Vamivakas and A. Kitt and A. Bauer},
year = {2021},
date = {2021-06-01},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {patent}
}
Nikolov, Daniel K.; Bauer, Aaron; Cheng, Fei; Kato, Hitoshi; Vamivakas, A. Nick; Rolland, Jannick P.
Metaform optics: Bridging nanophotonics and freeform optics Journal Article
In: Science Advances, vol. 7, no. 18, pp. eabe5112, 2021.
Abstract | Links | BibTeX | Tags: Aberration correction, augmented reality, CeFO manufacturing, CEFO metrology, freeform, head display, Image quality, Optical design, relay optics, rolland, tomography
@article{nokey,
title = {Metaform optics: Bridging nanophotonics and freeform optics},
author = {Daniel K. Nikolov and Aaron Bauer and Fei Cheng and Hitoshi Kato and A. Nick Vamivakas and Jannick P. Rolland},
url = {https://www.science.org/doi/abs/10.1126/sciadv.abe5112},
doi = {10.1126/sciadv.abe5112},
year = {2021},
date = {2021-04-30},
urldate = {2021-04-30},
journal = {Science Advances},
volume = {7},
number = {18},
pages = {eabe5112},
abstract = {The demand for high-resolution optical systems with a compact form factor, such as augmented reality displays, sensors, and mobile cameras, requires creating new optical component architectures. Advances in the design and fabrication of freeform optics and metasurfaces make them potential solutions to address the previous needs. Here, we introduce the concept of a metaform—an optical surface that integrates the combined benefits of a freeform optic and a metasurface into a single optical component. We experimentally realized a miniature imager using a metaform mirror. The mirror is fabricated via an enhanced electron beam lithography process on a freeform substrate. The design degrees of freedom enabled by a metaform will support a new generation of optical systems.},
keywords = {Aberration correction, augmented reality, CeFO manufacturing, CEFO metrology, freeform, head display, Image quality, Optical design, relay optics, rolland, tomography},
pubstate = {published},
tppubtype = {article}
}
The demand for high-resolution optical systems with a compact form factor, such as augmented reality displays, sensors, and mobile cameras, requires creating new optical component architectures. Advances in the design and fabrication of freeform optics and metasurfaces make them potential solutions to address the previous needs. Here, we introduce the concept of a metaform—an optical surface that integrates the combined benefits of a freeform optic and a metasurface into a single optical component. We experimentally realized a miniature imager using a metaform mirror. The mirror is fabricated via an enhanced electron beam lithography process on a freeform substrate. The design degrees of freedom enabled by a metaform will support a new generation of optical systems.
DeMars, Luke A.; Suleski, Thomas J.
Differentiation of Mid-Spatial Frequency Surface Errors Using Areal Power Spectral Density Presentation
ASPE Spring Topical Meeting: Freeform and Structured Surfaces, 29.04.2021.
BibTeX | Tags: CeFO related, Mid-Spatial Frequency error
@misc{DeMars_2021_2,
title = {Differentiation of Mid-Spatial Frequency Surface Errors Using Areal Power Spectral Density},
author = {Luke A. DeMars and Thomas J. Suleski},
year = {2021},
date = {2021-04-29},
urldate = {2021-04-29},
howpublished = {ASPE Spring Topical Meeting: Freeform and Structured Surfaces},
keywords = {CeFO related, Mid-Spatial Frequency error},
pubstate = {published},
tppubtype = {presentation}
}
Rolland, J. P.; Vamivakas, N.; Kitt, A.; Bauer, A.
Freeform Nanostructured Surface for Virtual and Augmented Reality Near Eye Display Patent
2021.
BibTeX | Tags: CeFO related
@patent{hwd_patent_CN21,
title = {Freeform Nanostructured Surface for Virtual and Augmented Reality Near Eye Display},
author = {J. P. Rolland and N. Vamivakas and A. Kitt and A. Bauer},
year = {2021},
date = {2021-04-06},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {patent}
}
Rolland, J. P.
A (Short) Journey Beyond Freeform Optics Proceedings
Proc. SPIE 11703, 2021.
Links | BibTeX | Tags: CeFO related
@proceedings{rolland_PW21,
title = {A (Short) Journey Beyond Freeform Optics},
author = {J. P. Rolland},
doi = {https://doi.org/10.1117/12.2585085},
year = {2021},
date = {2021-03-05},
urldate = {2021-03-05},
issue = {Proc. SPIE 11703},
howpublished = {Proc. SPIE 11703},
keywords = {CeFO related},
pubstate = {published},
tppubtype = {proceedings}
}
Lakshmanan, Sanjay N.; Lambropoulos, John C.
Twyman effect in thin curved optics: effects of variable thickness and curvature Journal Article
In: Applied Optics, vol. 60, iss. 6, pp. 1780-1789, 2021.
Abstract | BibTeX | Tags: CeFO related, fabrication
@article{nokey,
title = {Twyman effect in thin curved optics: effects of variable thickness and curvature},
author = {Sanjay N. Lakshmanan and John C. Lambropoulos},
year = {2021},
date = {2021-02-19},
urldate = {2021-02-19},
journal = {Applied Optics},
volume = {60},
issue = {6},
pages = {1780-1789},
abstract = {Grinding or finishing of thin curved optics introduces surface-localized stresses that may result in bending deformations, thus affecting optical performance (Twyman effect). The Twyman effect depends on local thickness of the optic as well as its curvature. We use numerical and analytical techniques to assess the effects of these variables for shallow and deeply curved axisymmetric optics. A useful metric of comparison, valid for shallow optics, is the deformation of a similar flat optic (window). This comparison is inadequate for more curved optics, which demonstrate a smaller deformation that is now localized in a boundary layer near the optic-free edge. The effects of thickness variation are also presented. Normal deflection and slope for a positive optic (thickness at the center greater than the tip) are well approximated by a constant thickness optic. This is not the case for a negative optic, where deformations near the apex are more pronounced, thus extending significant deformations through the full optic aperture.},
keywords = {CeFO related, fabrication},
pubstate = {published},
tppubtype = {article}
}
Grinding or finishing of thin curved optics introduces surface-localized stresses that may result in bending deformations, thus affecting optical performance (Twyman effect). The Twyman effect depends on local thickness of the optic as well as its curvature. We use numerical and analytical techniques to assess the effects of these variables for shallow and deeply curved axisymmetric optics. A useful metric of comparison, valid for shallow optics, is the deformation of a similar flat optic (window). This comparison is inadequate for more curved optics, which demonstrate a smaller deformation that is now localized in a boundary layer near the optic-free edge. The effects of thickness variation are also presented. Normal deflection and slope for a positive optic (thickness at the center greater than the tip) are well approximated by a constant thickness optic. This is not the case for a negative optic, where deformations near the apex are more pronounced, thus extending significant deformations through the full optic aperture.
Horvath, Nicholas; Davies, Matthew
Advancing lightweight mirror design: a paradigm shift in mirror preforms by utilizing design for additive manufacturing Journal Article
In: Applied Optics, vol. 60, iss. 3, pp. 681-696, 2021.
Abstract | Links | BibTeX | Tags: CeFO related, manufacturing
@article{Horvath_2021a,
title = {Advancing lightweight mirror design: a paradigm shift in mirror preforms by utilizing design for additive manufacturing},
author = {Nicholas Horvath and Matthew Davies},
doi = {https://doi.org/10.1364/AO.410350},
year = {2021},
date = {2021-01-18},
urldate = {2021-01-18},
journal = {Applied Optics},
volume = {60},
issue = {3},
pages = {681-696},
abstract = {Additive manufacturing is a disruptive technology that can be leveraged by the redesign of components in most engineering fields. Fundamental engineering resources for lightweight mirrors were developed more than 30 years ago with a main design limitation, state of the art manufacturing. Here, we present two design methodologies for the design of lightweight mirrors. The first method utilizes analytical expressions to design a traditional isogrid mirror, which provided the foundation for most lightweight mirrors to date. The second method employs a combination of topology optimization, lattice infill, and analytical estimation to develop an advanced lightweight mirror designed for additive manufacturing. The advanced mirror design outperforms the traditional design for each functional requirement, including a 94% reduction in predicted surface quilting and a higher specific stiffness. The manufacturing of the advanced mirror is only possible with an additive manufacturing process.},
keywords = {CeFO related, manufacturing},
pubstate = {published},
tppubtype = {article}
}
Additive manufacturing is a disruptive technology that can be leveraged by the redesign of components in most engineering fields. Fundamental engineering resources for lightweight mirrors were developed more than 30 years ago with a main design limitation, state of the art manufacturing. Here, we present two design methodologies for the design of lightweight mirrors. The first method utilizes analytical expressions to design a traditional isogrid mirror, which provided the foundation for most lightweight mirrors to date. The second method employs a combination of topology optimization, lattice infill, and analytical estimation to develop an advanced lightweight mirror designed for additive manufacturing. The advanced mirror design outperforms the traditional design for each functional requirement, including a 94% reduction in predicted surface quilting and a higher specific stiffness. The manufacturing of the advanced mirror is only possible with an additive manufacturing process.
2020
Sahoo, Pankaj K.; Feng, Tao; Qiao, Jie
Dynamic pulse propagation modelling for predictive femtosecond-laser-microbonding of transparent materials Journal Article
In: Opt. Express, vol. 28, no. 21, pp. 31103-31118, 2020.
Abstract | Links | BibTeX | Tags: manufacturing, related
@article{Sahoo2020,
title = {Dynamic pulse propagation modelling for predictive femtosecond-laser-microbonding of transparent materials},
author = {Pankaj K. Sahoo and Tao Feng and Jie Qiao},
doi = {https://doi.org/10.1364/OE.402493},
year = {2020},
date = {2020-10-02},
urldate = {2020-10-02},
journal = {Opt. Express},
volume = {28},
number = {21},
pages = {31103-31118},
abstract = {A dynamic pulse propagation modeling for femtosecond laser bonding of Borofloat glass is presented. The temperature evolution and internal modifications are predicted by incorporating the nonlinear electron dynamics along with temperature dependent thermal properties. The modelling predicts the spatial and temporal distribution of absorption coefficient and plasma density that gives quantitative estimations of the heat affected zone and weld geometry. The impact of focusing condition on heat affected zone and weld geometry is investigated, which for the first time to our knowledge allows to numerically determine the desired relative position between the geometrical focus of a femtosecond-laser-pulse and the interface of the two substrates to be welded. The prediction of the modelling on the offset distance is applied to weld Borofloat glass plates having optical contact and can be applied to other dielectric solids.},
keywords = {manufacturing, related},
pubstate = {published},
tppubtype = {article}
}
A dynamic pulse propagation modeling for femtosecond laser bonding of Borofloat glass is presented. The temperature evolution and internal modifications are predicted by incorporating the nonlinear electron dynamics along with temperature dependent thermal properties. The modelling predicts the spatial and temporal distribution of absorption coefficient and plasma density that gives quantitative estimations of the heat affected zone and weld geometry. The impact of focusing condition on heat affected zone and weld geometry is investigated, which for the first time to our knowledge allows to numerically determine the desired relative position between the geometrical focus of a femtosecond-laser-pulse and the interface of the two substrates to be welded. The prediction of the modelling on the offset distance is applied to weld Borofloat glass plates having optical contact and can be applied to other dielectric solids.