A new and inexpensive holographic technique for measuring the phase errors of a two-dimensional spatial light modulator (SLM) is described, and experimental verification is provided. A new technique to correct spatial phase errors in any SLM is then detailed and experimentally demonstrated. This technique is employed for the Radio Shack liquid-crystal television SLM, and a shift-invariant correlator is obtained. Additional low-pass filtering techniques (appropriate for any SLM with a fixed pattern of modulating cells) are discussed that provide improved contrast and achieve proper correlations.
© 1986 Optical Society of America
Original Manuscript: February 18, 1986
Manuscript Accepted: March 31, 1986
Published: June 1, 1986
David Casasent and Shao-Feng Xia, "Phase correction of light modulators," Opt. Lett. 11, 398-400 (1986)