CeFO Publications

@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}

}

@article{Aryan2019e,

title = {Simple methods for estimating the performance and specification of optical components with anisotropic mid-spatial frequency surface errors},

author = {Hamidreza Aryan and Glenn D. Boreman and Thomas J. Suleski},

url = {https://doi.org/10.1364/OE.27.032709},

doi = {https://doi.org/10.1364/OE.27.032709},

year  = {2019},

date = {2019-10-25},

journal = {Optics Express},

volume = {27},

number = {22},

pages = {32709-32721 },

keywords = {CeFO, CeFO manufacturing, manufacturing, Mid-Spatial Frequency error},

pubstate = {published},

tppubtype = {article}

}

@article{TAYLOR2019,

title = {Femtosecond laser polishing of germanium},

author = {LAUREN L. TAYLOR, JING XU, MICHAEL POMERANTZ, THOMAS

R. SMITH, JOHN C. LAMBROPOULOS, AND JIE QIAO},

url = {https://doi.org/10.1364/OME.9.004165},

year  = {2019},

date = {2019-10-02},

journal = {Optical Materials Express},

volume = {9},

number = {11},

pages = {4165-4177},

abstract = {Freeform optics can reduce the cost, weight, and size of advanced imaging systems,

but it is challenging to manufacture the complex rotationally asymmetric surfaces to optical

tolerances. To address the need for disruptive, high-precision sub-aperture forming and finishing

techniques for freeform optics, we investigate an alternative, non-contact polishing methodology

using femtosecond lasers, combining modeling, experiments, and demonstrations. Femtosecondlaser-

based polishing of germanium was investigated using an experimentally-validated twotemperature

model of laser/germanium interaction to guide the understanding and selection of

laser parameters to achieve near-nonthermal ablation for polishing and figuring. For the first time

to our knowledge, model-guided femtosecond laser polishing of germanium was successfully

demonstrated, achieving precision material removal while maintaining single-digit nanometer

optical surface quality. The demonstrated femtosecond-laser-based polishing technique lays the

foundation for semiconductor optics polishing/fabrication using femtosecond lasers and opens a

viable path for high-precision, complex sub-aperture optical polishing tasks on various materials.},

keywords = {CeFO manufacturing, CEFO metrology, fabrication, Freeform surfaces, manufacturing, Mid-Spatial Frequency error},

pubstate = {published},

tppubtype = {article}

}

@article{Horvath19-a,

title = {Kinematic mirror mount design for ultra-precision manufacturing, metrology, and system level integration for high performance visible spectrum imaging systems},

author = {Nicholas W. Horvath and Matthew A. Davies and Steven R. Patterson},

url = {https://doi.org/10.1016/j.precisioneng.2019.09.011},

year  = {2019},

date = {2019-09-20},

journal = {Precision Engineering},

volume = {60},

pages = {535-543},

abstract = {High-performance freeform optical systems, designed for broad spectral imaging from the visible to the far infrared, place new demands on optical design, precision manufacturing, and precision metrology. To meet the tolerances on figure, roughness, and relative positioning in such systems requires the ability to perform metrology and manufacturing corrections on freeform optics in a continuous feedback loop. This feedback loop requires a common interface for machining and manufacturing platforms. This paper describes the design, analysis, and testing of such an interface suitable for use with single point diamond turning and deterministic micro-grinding. The interface utilizes a torsionally preloaded, robust, kinematic mount capable of supporting manufacturing process loads while maintaining the position repeatability in five degrees of freedom required for the measurement and correction of optical figure. Results from a prototype system demonstrate absolute in-plane position uncertainty less than 200 nm and 50 nm, respectively, and axial position uncertainty is 40 nm absolute and 10 nm relative. The absolute and relative angular positioning uncertainties less than 1 µrad and 0.25 µrad respectively. The results exceed the requirements for many optical systems. The mount is also suitable for use in opto-mechanical assembly, so that the same platform can be used for manufacturing, metrology, final assembly, testing, and service.},

keywords = {CeFO, CeFO manufacturing, CEFO metrology, Freeform surfaces, Kinematic Coupling},

pubstate = {published},

tppubtype = {article}

}

@article{Aryan2019d,

title = {The Minimum Modulation Curve as a tool for specifying optical performance: application to surfaces with mid-spatial frequency errors},

author = {Hamidreza Aryan and Glenn D. Boreman and Thomas J. Suleski},

url = {https://doi.org/10.1364/OE.27.025551},

doi = {https://doi.org/10.1364/OE.27.025551},

year  = {2019},

date = {2019-08-23},

journal = {Optics Express},

volume = {27},

number = {18},

pages = {25551-25559},

keywords = {CeFO, CeFO manufacturing, Mid-Spatial Frequency error},

pubstate = {published},

tppubtype = {article}

}

@article{LIANG2019,

title = {Validity of the perturbation model for the propagation of MSF structure in 2D},

author = {Kevin Liang and G.W. Forbes and Miguel A. Alonso},

editor = {Optical Society of America},

url = {https://doi.org/10.1364/OE.27.003390},

doi = {10.1364/OE.27.003390},

year  = {2019},

date = {2019-02-04},

journal = {Optics Express},

volume = {27},

number = {3},

pages = {3390-3408},

abstract = {Assessment of the performance degradation caused by the mid-spatial frequency (MSF) structure on optical surfaces often relies on a perturbation method that dovetails with the familiar sequence of models based on geometrical and physical optics. In the case of imaging systems, the perturbative step yields estimates of wavefronts in the exit pupil which are, in turn, used to extract performance measures such as MTF, PSF, and Strehl ratio. To date, the validity of that perturbation appears to be poorly understood. We present methods to estimate the errors of this approach and thereby arrive at a rule of thumb for its accuracy: the error is approximately equal to the RMS of the MSF structure at its source multiplied by the square of the ratio between a particular Fresnel zone size and a characteristic length of the MSF structure.},

keywords = {CeFO, CeFO design, CeFO manufacturing},

pubstate = {published},

tppubtype = {article}

}

@article{Owen2017,

title = {Error correction methodology for ultra-precision three-axis milling of freeform optics},

author = {J.D. Owen and J.A. Shultz and T.J. Suleski and M.A. Davies},

url = {https://doi.org/10.1016/j.cirp.2017.04.031},

year  = {2017},

date = {2017-05-02},

journal = {CIRP Annals},

volume = {66},

number = {1},

pages = {97-100},

abstract = {Freeform optics facilitate a revolutionary approach to optical design. Ultra-precision diamond machining is an enabling technology for the manufacture of freeform optics. However, optical designs require tight tolerances across spatial wavelengths ranging from micro-roughness to overall form. To manufacture freeform optics to the necessary tolerances, a novel artifact-based error reduction methodology applicable to multi-axis diamond milling was developed. As demonstrated on a test sphere, the methodology reduces dominant error sources on the test sphere surface from 194 to 40 nm RMS. The approach is then successfully applied to an example freeform optical design where comparable error levels are achieved.},

keywords = {CeFO, CeFO manufacturing, CEFO metrology},

pubstate = {published},

tppubtype = {article}

}

@article{Shahinian16,

title = {An Evaluation of Fiber-Based Tools for Glass Polishing Using Experimental and Computational Approaches},

author = {Shahinian, H. and H. Cherukuri and B. Mullany},

doi = {https://doi.org/10.1364/AO.55.004307},

year  = {2016},

date = {2016-06-01},

urldate = {2016-06-01},

journal = {Applied Optics},

volume = {45},

number = {16},

pages = {4307-4316},

abstract = {Polymeric pad or pitch-based tools combined with loose abrasive slurries are typically used in the polishing of optical materials. In this paper, the potential of fiber-based tools to both remove material and provide high quality surface finishes on BK7 glass is explored. The potential advantage of fiber-based tools over traditional tools is their inherent compliance, which could accommodate varying workpiece surface curvatures as found in aspheres and freeforms. To evaluate the new tools, both experimental and finite element (FE) modeling approaches were taken. A FE model consisting of a single fiber engaged with the workpiece surface was used to estimate the shape and magnitude of the pressure distribution exerted by the fiber on the workpiece surface. Two different tool configurations, yielding two different Fes, predicted pressure distributions, were used to polish BK7 samples, and the material removal profiles were interferometrically measured. The resulting profiles and the predicted pressure distributions share the same v-shape. While differences in scale exist between the experimental and FE-predicted profiles, the tool generating higher material removal had the greater predicted pressure distribution, thus demonstrating the ability of the FE model to provide insights into tool design. Additional testing was conducted to determine if the tool’s removal rate can be predicted by Preston’s equation. Initial results indicate the equation is valid within the range of parameters tested. The surface roughness of BK7 samples processed by this tool was measured and some deterioration on the Sq value was noted; the surface roughness increased from 1.89 to 3.66 nm Sq. Over several hours of continuous use, the load applied by the fibers decays in a repeatable manner, and little wear was observed on the fibers after 5.33 h of polishing.},

keywords = {CeFO manufacturing},

pubstate = {published},

tppubtype = {article}

}