Optical testing using a Spatial Light Modulator as a Programmable Computer Generated Hologram

Spatial Light Modulators (SLM) have become essential optical laboratory tools, by their ability to reshape a monochromatic and linearly polarized beam almost as needed. SLMs have the potential to enable interferometric testing of aspheric or even freeform optical surfaces, with the advantage to avoid manufacturing an expensive bulk optics null-corrector or a Computer Generated Hologram for each surface to be tested. Thus a single SLM would be sufficient for moderate accuracy optical testing of a wide range of optical surfaces.

The objectives of this master thesis is to review the state of the art of optical testing with SLMs, identify the limitations, design and implement a set-up to test an in-house moderate aspheric mirror, and finally validate the performance. The test set-up will be based on the following hardware and already available at ESO: a 6inches 5.3 Mpixels, Zygo verifier HD interferometer, a Spatial Light Modulator Holoeye PLUTO-2-VIS-096.