Papers and Presentations

Optomechanical analysis of compliant spacers in passively athermalized drop-in optical systems

October 2022

Author: Martin Tangari Larrategui, et al.

Passively athermalized optical systems produce high quality images over a large thermal range without actively adjusting focus. This athermalization is achieved through careful selection of the glass for each lens and metal for each mount. For drop-in systems, the material combination for best optical performance often leads to a lens stack with an overall coefficient of thermal expansion (CTE) that is different from the CTE of the barrel that holds it together.

Realistic Optical System Tolerancing: A Practical Example

January 2021

Author: Lee Johnson

While lens design software can assist with tolerancing, complex and/or critical optical systems require expertise beyond the software’s basic functionality. We represent tolerancing of optical systems as close to reality as possible by utilizing the most advanced tolerancing tools both built into lens design software and of our own creation.

Metrology in Optics Manufacturing and Optical System Assembly

Presented by Dr. Kate Medicus

January 2021

Metrology of optics and optical systems is a challenging tasks without one easy solution. In many ways, metrology in the manufacturing of lenses and mirrors is well understood. But, for the most part, there are commercial tools and software that are adequate for many optical components. This talk will review these metrology concepts and provide an overview of research in this area.

The metrology of optical systems is more challenging and not as well established and understood. There are many requirements and specifications in optical systems that require measurements, but the methods to measure these specifications have not undergone rigorous testing or uncertainty analysis. The complexity of multi-element systems does not allow for easy to understand feedback to the manufacturing/assembly process or to the as-designed models. This talk will discuss the challenges and on-going issues in metrology of multi-element optical systems.

Concentric Mount for Off-Axis Parabola Alignment

Authors: Kenneth R. Castle, Kate Medicus, Lee Johnson, Christopher Giokaris

November 2020

Off-axis parabolas (OAPs) have advantages in many different light-based applications – defense, space, medical, and lithographic – mainly because they can focus/collimate without aberrations. OAPs are notoriously difficult to align, though, and, in many systems, there are multiple OAPs, thereby increasing the alignment problems. Weeks can be spent trying to align these systems. In this paper, we show a method and mount for accurately aligning OAPs to any coordinate system. This method is applicable to multiple OAP systems because the OAPs can be aligned to each other.

Sensitivity analysis of the CTE and thermo-optical coefficients of a passively athermalized lens

Martin Tangari Larrategui, Victor E. Densmore III, Lee Johnson, Christopher Giokaris, Kate Medicus, Kenneth R. Castle, and Tilman W. Stuhlinger "Sensitivity analysis of the CTE and thermo-optical coefficients of a passively athermalized lens", Proc. SPIE 11488, Optical System Alignment, Tolerancing, and Verification XIII, 1148809 (20 August 2020); https://doi.org/10.1117/12.2569759

Using spherical aberration as a tool in aligning off-axis aspheric mirrors

As described in “Introduction to Optical Alignment Techniques”, a short course long offered through SPIE

Kenneth R. Castle "Using spherical aberration as a tool in aligning off-axis aspheric mirrors, as described in “Introduction to Optical Alignment Techniques”, a short course long offered through SPIE", Proc. SPIE 11488, Optical System Alignment, Tolerancing, and Verification XIII, 114880G (20 August 2020); https://doi.org/10.1117/12.2569922

As-Fab Elements: Design vs. Reality

Victor E. Densmore III, Christopher M. Shanor, Isela D. Howlett, Kate Medicus, Tilman Stuhlinger, and Kenneth R. Castle "As-fab elements: design vs. reality", Proc. SPIE 10747, Optical System Alignment, Tolerancing, and Verification XII, 107470G (19 September 2018); https://doi.org/10.1117/12.2324941

Introduction to optical alignment techniques: a long-running SPIE short course

Kenneth R. Castle "Introduction to optical alignment techniques: a long-running SPIE short course", Proc. SPIE 10747, Optical System Alignment, Tolerancing, and Verification XII, 107470B (19 September 2018); https://doi.org/10.1117/12.2321326

Efficient automatic computation of veiling glare from scatter and ghosts by a simple modification to Monte Carlo ray tracing

Alan W. Greynolds "Efficient automatic computation of veiling glare from scatter and ghosts by a simple modification to Monte Carlo ray tracing", Proc. SPIE 8840, Optical Modeling and Performance Predictions VI, 884007 (27 September 2013); https://doi.org/10.1117/12.2019942

Multi-core and GPU accelerated simulation of a radial star target imaged with equivalent t-number circular and Gaussian pupils

Alan W. Greynolds "Multi-core and GPU accelerated simulation of a radial star target imaged with equivalent t-number circular and Gaussian pupils", Proc. SPIE 8841, Current Developments in Lens Design and Optical Engineering XIV, 88410F (25 September 2013); https://doi.org/10.1117/12.2021036

Scalability of a cross-platform multi-threaded non-sequential optical ray tracer

Alan W. Greynolds "Scalability of a cross-platform multi-threaded non-sequential optical ray tracer", Proc. SPIE 8129, Novel Optical Systems Design and Optimization XIV, 81290C (9 September 2011); https://doi.org/10.1117/12.891920

Free-space propagation of extreme NA polarized beams using the vector plane wave spectrum method and multi-gigabyte FFTsV

Alan W. Greynolds "Free-space propagation of extreme NA polarized beams using the vector plane wave spectrum method and multi-gigabyte FFTsV", Proc. SPIE 7427, Optical Modeling and Performance Predictions IV, 742702 (1 October 2009); https://doi.org/10.1117/12.825489

Design, Analysis, and Fabrication of a Really Bad Lens

Alan W. Greynolds "Design, analysis, and fabrication of a really bad lens", Proc. SPIE 7429, Novel Optical Systems Design and Optimization XII, 74290E (21 August 2009); https://doi.org/10.1117/12.825480

Stray light computations: Has nothing changed since the 1970s?

Alan W. Greynolds "Stray light computations: Has nothing changed since the 1970s?", Proc. SPIE 6675, Optical Modeling and Performance Predictions III, 66750B (25 October 2007); https://doi.org/10.1117/12.730258

Anomaly detection using the hyperspectral polarimetric imaging testbed

David B. Cavanaugh, Kenneth R. Castle, and Wayne Davenport "Anomaly detection using the hyperspectral polarimetric imaging testbed", Proc. SPIE 6233, Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XII, 62331Q (4 May 2006); https://doi.org/10.1117/12.666133

Hyperspectral polarimetric imaging testbed d

David B. Cavanaugh, Yannick P. Gargadennec, Brian Catanzaro, Kenneth R. Castle, and Wayne Davenport "Hyperspectral polarimetric imaging testbed", Proc. SPIE 5806, Algorithms and Technologies for Multispectral, Hyperspectral, and Ultraspectral Imagery XI, (1 June 2005); https://doi.org/10.1117/12.611238