Fullin-situcharacterization of spatial light modulators in an optical correlator. Filter adaptation to operating curves

Abstract

In this paper we present one method for the characterization of the spatial light modulators (SLMs) of a real-time Vander Lugt type of correlator. This correlator uses two SLMs: one to introduce the scene and a second to introduce the frequency-matched filter. T h e S L M characterization methods are in situ, that is in the correlator set-up. Illumination conditions are different for each SLM, and consequently different characterization techniques must be used in each case. For the characterization of the scene S L M a diffraction method is used, while for the characterization of the filter S L M an interferometric technique is more convenient. Finally, we take into account the operating curves of scene and filter SLMs in the design of the filter in order to optimize the correlation peak.

Evaluation and correction of aberrations in an optical correlator by phase-shifting interferometry

“…11 Moreover, aberrations introduced by modulators and the various elements depend strongly on the orientation of all elements; thus to evaluate these aberrations it is necessary to develop a method that allows this task to be performed in situ.…”