Off-axis Hartmann wavefront sensing for the GMT-Consortium Large Earth Finder (G-CLEF) red camera optics

Matthew C. H. Leung; Colby A. Jurgenson; Andrew Szentgyorgyi; Brian McLeod; Cem Onyuksel; Joseph Zajac; David Charbonneau; William Podgorski; Abigail Unger; Mark Mueller; Matthew Smith; Daniel Baldwin; V. Ashley Villar

doi:10.1117/12.3018467

18 July 2024 Off-axis Hartmann wavefront sensing for the GMT-Consortium Large Earth Finder (G-CLEF) red camera optics

Matthew C. H. Leung, Colby A. Jurgenson, Andrew Szentgyorgyi, Brian McLeod, Cem Onyuksel, Joseph Zajac, David Charbonneau, William Podgorski, Abigail Unger, Mark Mueller, Matthew Smith, Daniel Baldwin, V. Ashley Villar

Author Affiliations +

Proceedings Volume 13096, Ground-based and Airborne Instrumentation for Astronomy X; 130964M (2024) https://doi.org/10.1117/12.3018467
Event: SPIE Astronomical Telescopes + Instrumentation, 2024, Yokohama, Japan

Conference Poster

Abstract

The Hartmann test is a method used to measure the wavefront error in a focal optical system, wherein a mask with a pattern of small holes is placed at the system’s aperture stop. By taking an image at a defocused plane, the differences between the ideal and real positions of the reimaged holes (called the transverse ray aberrations) can be measured, which can then be used to estimate the wavefront error. However, the Hartmann test is usually used with an on-axis field. In this paper, we present a wavefront sensing method which generalizes the classical Hartmann test for off-axis field angles and arbitrary reference wavefronts. Our method involves taking images at two defocused planes, and then using the real reimaged hole positions on both planes to estimate the trajectories of rays from the system’s exit pupil, at which the reference wavefront is situated. We then propagate the rays forward from the reference wavefront to one of the two defocused planes, in order to find the ideal reimaged hole positions, from which we can compute transverse ray aberrations. We derive and solve a pair of nonlinear partial differential equations relating transverse ray aberrations to wavefront error, using Zernike decomposition and nonlinear least squares. Our method has been verified on simulated data from the 7-lens f/2.25 red camera system of the GMT-Consortium Large Earth Finder (G-CLEF), a high resolution optical echelle spectrograph which will be a first light instrument for the Giant Magellan Telescope (GMT).

(2024) Published by SPIE. Downloading of the abstract is permitted for personal use only.

Citation Download Citation

Matthew C. H. Leung, Colby A. Jurgenson, Andrew Szentgyorgyi, Brian McLeod, Cem Onyuksel, Joseph Zajac, David Charbonneau, William Podgorski, Abigail Unger, Mark Mueller, Matthew Smith, Daniel Baldwin, and V. Ashley Villar "Off-axis Hartmann wavefront sensing for the GMT-Consortium Large Earth Finder (G-CLEF) red camera optics", Proc. SPIE 13096, Ground-based and Airborne Instrumentation for Astronomy X, 130964M (18 July 2024); https://doi.org/10.1117/12.3018467

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