Optical Switch Study.

Nineteen techniques for implementing an optical communications switch in an integrated optical circuit have been examined. The optical matrix switch is intended to interconnect n optical inputs with n optical outputs at a 10 GHz bandwidth. The most promising optical switching approaches were found to be electrically-controlled, optical directional-couplers and electro-optic, Bragg, diffraction-gratings. Both are realizable in optical microcircuit form. An optical balanced bridge is the optimum form of the coupler switch. The switchable couplers can be built from optical channel waveguides that have 2D mode confinement, while the gratings would be embodied in a slab guide with 1D confinement. The latter arrangement is more vulnerable to optical crosstalk in a matrix. Electro-optic phase perturbation in the deflectors and couplers is preferred for its simplicity, low driving power, and nanosecond switching speeds. An n squared matrix array of switches has been designed with 2n absorbing terminations at the unused ports.