TRAVELING WAVE-ELECTRO ABSORPTION MODULATOR

摘要

PURPOSE: A P+-n-i-p-N+ traveling wave-electro absorption modulator is to match a phase velocity of the light wave with a phase velocity of a microwave, thereby enhancing the bandwidth. CONSTITUTION: A P type layer and an N type layer are doped in a semi-insulating substrate to allow a transmission mode of a microwave to be in a slow-wave mode. A p-i-n diode includes an i-layer of bulk or multiple quantum well(MQW) and absorbs the light wave and provides a modulated light wave. A P-layer is formed on an N+ layer of the p-i-n diode. An N-layer is formed beneath a P+ layer of the p-i-n diode. A PMMA(polymethylmethacrylate) layer is formed on both sidewalls of the p-i-n diode to prevent the light wave from being leaked. A signal electrode(11) is formed on the P+ layer and the PMMA layer. A ground electrode(12,13) is formed on left end portion and right end portion of the N+ layer.