Full in-situ characterization of spatial light modulators in an optical correlator. Filter adaptation to operating curves

Abstract

Fu ll in -situ c h arac te r iz ation of spatial ligh t m od u lators in an optic al c orre lator. Filte r ad aptation to ope ratin g c u rv e s Abs trac t.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 ® lter. The SLM characterization methods are in situ, that is in the correlator set-up. Illumination conditions are di erent for each SLM, and consequently di erent characterization techniques must be used in each case. For the characterization of the scene SLM a di raction method is used, while for the characterization of the ® lter SLM an interferometric technique is more convenient. Finally, we take into account the operating curves of scene and ® lter SLMs in the design of the ® lter in order to optimize the correlation peak.

Operating curve extraction of a correlator’s filter

“…7,8 However, our new method differs in the restriction that the light beam in the correlator is not accessible, in the manner in which the input plane is implemented, and in the way the operating curve is extracted.…”

Teaching optics with a spatial light modulator

“…Twisted-nematic liquid crystal televisions are used as intensity or phase modulators in a great variety of applications, [1][2][3][4] because they can be obtained relatively cheaply from commercial video projector units. Furthermore, these devices have greater resolution than other devices specifically designed to be used as phase modulators in scientific applications.…”