High-speed optical signal processing potential of grating-coupled waveguide filters

The application of grating-coupled waveguides to spread spectrum fiber-optic communications systems is described. It is first shown that such a device can act as its own matched filter for impulsive excitation, which allows its use as an encoder and decoder of ultrashort pulses. This is true even in the case of strong coupling, although considerable pulse distortion occurs. A typical performance that might be expected from existing technology is then outlined, and a number of numerical examples are presented to illustrate typical signal processing operations.