OPTOELECTRONIC INTEGRATED CIRCUIT

摘要

PURPOSE:To integrate an optical waveguide and a photodetecting device conformably into an optoelectronic integrated circuit (OEIC) by an exceedingly simple process by forming an optical absorption layer on an optical waveguide layer which makes up the optical waveguide and also by forming a photodetector having an MSM structure on the optical absorption layer. CONSTITUTION:An optical waveguide 2 consisting of undoped AlxGa1-xAs (x=0.2) is formed on a substrate 1 and an input light comes from an end face 2A. An optical absorption layer 3 consisting of gallium arsenide (GaAs) is provided on the optical waveguide 2 and both end faces of this layer 3 are slantingly cut. And one side end face is also obliquely cut together with the optical waveguide 2. An MSM photodetector that is composed of a pair of comb type electrodes 4 and 5 where electrodes like teeths of a comb are alternately arranged on the optical absorption layer 3 as well as on the optical absorption layer 3 located at its one side slanting part and on the optical waveguide 2. Accordingly, the formation of the MSM photodetector on the slanting part of the optical absorption layer allows optical impedance to vary gradually at the slanting part and then, its photodetector is so free from reflection of a light that is detects efficiently the light.