OPTICAL SIGNAL DISTRIBUTION IN WAVE-GUIDE-COUPLED METAL-SEMICONDUCTOR-METAL DETECTOR ARRAYS

We report the use of waveguide-coupled GaAs metal-semiconductor-metal (MSM) photodetectors for signal distribution in an optoelectronic matr ix switch. The power delivered to multiple detectors that are placed i n-line on a single AlGaAs waveguide can be balanced by varying the det ector lengths along the propagation direction and by controlling the d egree of coupling between the waveguiding end absorbing layers. The de pendence of the coupling strength on the thicknesses of the absorbing layer and the buffer layer that separates it from the waveguide was mo deled numerically, Experimentally, the coupling strength was varied by tuning the operating wavelength across the GaAs band edge. Uniform po wer distribution among four in-line detectors was demonstrated.