Practical optical beamforming networks

A review of optical beamforming techniques is presented. The techniques are subdivided into two broad categories. First, several representative implem entations of narrow band, phase-only techniques are summarized. A detailed description of a narrow band architecture realized in our laboratory is pre sented. The architecture is based on coherent heterodyning of two narrow li newidth Nd:YAG lasers, with a controlled angular beam offset to generate th e required microwave phase progression. Second, several representative wide band, true time delay architectures are briefly described. A description of a 'dispersive-prism' based true time-delay technique developed in our labo ratory is presented. The results show multi-octave one-dimensional transmit and receive true time-delay beamformer operation, as well as two-dimension al transmit beamformer operation.