Optical signal processors and applications

In the last few years, a considerable effort has been expended on the development of a number of both active and passive guided-wave devices, such as laser diodes, electrooptic modulators, acoustooptic transducers, photodetectors and microlens arrays, for optical signal processing applications including optical computing 1-3. Many simple optical devices can be easily fabricated by using mature and reproducible technologies. The interest in optical processors involving simple devices is mainly due to a lower power consumption, reduced size, cost and weight and high throughput with respect to the corresponding electronic processors. A number of guided-wave optical circuits for communications, signal processing and optical computing have been demonstrated using the acoustooptic, magnetooptic and electrooptic effects 4. Moreover, fields of application of particular interest are synthetic aperture radar (SAR), remote sensing and beam forming of linear array antennas, which are all well suited for optics-based processing because of the parallel processing allowed by optical architectures. Therefore, guided-wave optical processors can be successfully applied to the optical control of microwaves, to the reconstruction of two-dimensional images using both spatial and time integration, to data classification and identification in satellite applications and for performing a number of signal processing and optical computing functions