COMPOSITE DIFFRACTION GRATINGS FOR SIGNAL PROCESSING AND OPTICAL CONTROL APPLICATIONS

摘要

The present invention provides a composite grating structure that performs a programmed complex-valued, spectral filtering function on an input optical signal. The grating consists of a plurality of subgratings. Each subgrating controls the diffraction of a specific optical subbandwidth of light from an operative input direction to an operative output direction imparting a controllable amplitude and phase change onto the specific subbandwidth of light whose diffraction it controls within the overall operative bandwidth. The set of subgratings comprising the composite grating collectively controls the diffraction of an operative bandwidth of light from an operative input direction to an operative output direction. Each composite grating is programmed through their construction or through their dynamic modification to provide desired spectral filtering functions. While the composite gratings can be employed for general spectral filtering applications, they hold especially attractive potential in the area of optical waveform processing, generation, and detection.