Stray Light Analysis and Control

Level: Introductory Length: 6 hours Format: Online Intended Audience: Designers, builders, testers, and users of optical systems who wish to learn more about the causes of stray light and the best methods to control it. Undergraduate training in engineering or science is assumed. Description: This course explains the basic principles of designing, building, and testing optical systems whose stray light performance is adequate for their intended purpose. It teaches methods to identify stray light problems in the design phase when they can be most easily and inexpensively fixed, and does not emphasize the use of any particular stray light analysis software, but rather the fundamental principles of radiometry and optical design necessary to use such software effectively. Application of the course material is demonstrated in class by measuring the stray light performance of a simple camera system and comparing the measurement to both first order estimates and detailed ray tracing results. Learning Outcomes: This course will enable you to: - explain the meaning of the phrase "Move it or block it" - differentiate between in-field and out-of-field stray light - differentiate between internal and external stray light - explain the pros and cons of basic radiometric analysis vs. detailed ray tracing analysis - quantify stray light in an optical system using standard metrics such as Point Source Transmittance and Veiling Glare - quickly estimate the stray light performance of a simple optical system using basic radiometry - identify problematic stray light paths in an optical system by performing a backwards ray trace in stray light analysis software - use techniques such as ray aiming and statistical analysis to reduce the time required to complete a ray trace - verify the result of a ray tracing analysis with basic radiometry - list the primary mechanisms of stray light - predict the BSDF of a contaminated optical surface from its IEST-1246C cleanliness level - predict the BSDF of an optical surface from its surface roughness statistics - measure the BSDF of a surface - list popular black surface treatments (such as anodize) used to control stray light - use anti-reflection coatings to reduce stray light due to ghost reflections - explain the root cause of large unit-to-unit variably in stray light performance - design an optimal set of baffle vanes - design primary mirror baffles for Cassegrain telescopes - design stray light control features such as field stops and relayed pupils - measure the stray light performance of an optical system - define meaningful stray light performance requirements - explain the benefit of having a stray light model whose predictions have been correlated with measurements Instructor(s): Eric C. Fest has been developing stray light control systems for the optics industry for 25 years, and is currently an Optical Scientist at Facebook Reality Labs. He is the author of numerous publications on the topic of stray light, including the SPIE Press best-selling book Stray Light Analysis and Control. He has a Ph.D. in Optical Sciences from the University of Arizona. SPIE online courses are on-demand and self-paced, with access for one year. For more information visit: spie.org/education/online-courses