In-lab calibration and testing of adaptive secondary mirrors using phase measuring deflectometry

Ruihan Zhang; Mark R. Chun

doi:10.1117/12.2627278

29 August 2022 In-lab calibration and testing of adaptive secondary mirrors using phase measuring deflectometry

Ruihan Zhang, Mark R. Chun

Proceedings Volume 12185, Adaptive Optics Systems VIII; 1218569 (2022) https://doi.org/10.1117/12.2627278
Event: SPIE Astronomical Telescopes + Instrumentation, 2022, Montréal, Québec, Canada

Conference Poster

Abstract

An adaptive secondary mirror (ASM) with novel actuator technology is being designed and built for the UH88 telescope as a demonstration of a new generation of ASMs that might be deployed at ground based observatories such as Keck, Subaru, and TMT. Before putting the ASM on the telescope, a set of calibrations and characterizations need to be made in the lab. The crucial lab characterizations of the ASM are to measure its influence functions, and its surface shape when powered and unpowered. To measure these, we develop a novel and inexpensive optical metrology approach using phase measuring deflectometry. This paper describes the simulations we wrote to model the deflectometry method, our data acquisition/analysis pipeline, and a lab prototype system we built that demonstrates its feasibility on a microelectromechanical systems (MEMS) deformable mirror. Based on the information gained through the deflectometry simulation and the setup prototype, we conclude that phase measuring deflectometry is a reasonable method for obtaining the influence functions but that the absolute surface shape of the ASM will be limited by our knowledge of the placement of components within the deflectometry setup itself. We discuss challenges with extending this approach to larger convex adaptive secondary mirrors.

Citation Download Citation

Ruihan Zhang and Mark R. Chun "In-lab calibration and testing of adaptive secondary mirrors using phase measuring deflectometry", Proc. SPIE 12185, Adaptive Optics Systems VIII, 1218569 (29 August 2022); https://doi.org/10.1117/12.2627278

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available