An optical apparatus is disclosed for processing light that based on a pair of diffraction gratings operating in tandem, with one of the gratings being a fixed diffraction grating and with the other grating being electrically programmable. The combination of the fixed and electrically-programmable diffraction...http://www.google.se/patents/US20020105725?utm_source=gb-gplus-sharePatent US20020105725 - Electrically-programmable optical processor with enhanced resolution
