Abstract

The Integrated Optical Synthetic Aperture Radar (IOSAR) Processor [1] is one of a number of potentially powerful optical signal processing components that combine many of the throughput characteristics of bulk optical processors with the cost, size, and power advantages of guided wave optical devices. One of several novel features of the IOSAR processor is the capability of performing an inherently two dimensional image formation function in an integrated optical configuration by a combination of spatial and temporal integration. This can be accomplished as shown schematically in Fig. 1. The radar return (a linear FM chirp) is input to the processor by means of a surface acoustic wave transducer. Coherent light from a pulsed laser diode is collimated by lens L₁ and focused on an array of rib waveguides by lens L₂ (a spatial integration). The large area waveguide array performs an image dissection in the range dimension. Light propagating in a given rib waveguide (a given range bin) is then selectively outcoupled through a mask encoded with the azimuth doppler history onto a two dimensional CCD detector operated in the shift-and-add mode. Sequential radar returns are then integrated with appropriate shifts (a temporal integration) to perform the required azimuth compression.

© 1988 Optical Society of America