The accuracy and flexibility of the technique proposed by Davis <i>et al</i>. [Appl. Opt. <b>35,</b> 2488 (1996)] for the encoding of the amplitude and the phase of a filter onto a single liquid-crystal spatial light modulator operating in a phase-only regime has been exploited to implement several filter designs in a convergent optical correlator. We have selected some filters, that given their mathematical structure showing some degree of rotational invariance, or having a parameter to regulate their behavior, require a more precise encoding. We present correlation results of outstanding quality for various rotationally invariant filter designs that have never been previously implemented with a real-time optical correlator.
© 2003 Optical Society of America
(100.4550) Image processing : Correlators
(100.5010) Image processing : Pattern recognition
(100.5760) Image processing : Rotation-invariant pattern recognition
(230.6120) Optical devices : Spatial light modulators
Oscar Gualdrón, Jeffrey Davis, Josep Nicolás, Juan Campos, and Maria J. Yzuel, "Complex Encoding of Rotation-Invariant Filters onto a Single Phase-Only Spatial Light Modulator," Appl. Opt. 42, 1973-1980 (2003)