A Review of Recent Progress on Guided-Wave Acoustooptics with Applications to Wideband Communications and Signal Processing*

Abstract

Recent research in planar guided-wave acoustooptics(1) has produced very significant progress. It is now possible to design and fabricate high-performance planar acoustooptic (AO) Bragg modulators and deflectors with a bandwidth approaching one GHz.(2) For example, the deflectors of 700 and 470 MHz have been realized most recently in Y-cut LiNbO3 waveguides using multiple tilted transducers(1-3) and a tilted-finger chirp transducer,(2-4) respectively. Together with recent progress on fabrication of miniature laser sources, waveguide geodesic lenses, and photodetector arrays, integration of all or most of these components on a common substrate is becoming a reality. Clearly, the resulting integrated AO modules or circuits should find a number of unique applications in wideband multichannel optical communications and rf signal processing. One application that has already received a great deal of attention and interest is real-time spectral analysis of wideband rf signals.(5-9) Other applications, such as correlation, convolution, pulse compression and matched filtering of rf signals,(2,10) and multiport switching of optical signals in a single-mode fiber optic communication system,(2,11) should not be far behind.