Semiconductor optical integrated circuits

Abstract

A semiconductor optical monolithic integration device comprises a semiconductor substrate including an active region and a passive region. Epitaxial layers including a multiple quantum well structure have a variation in band gap energy and thickness along a waveguide direction. The epitaxial layers in the active region are selectively grown by a metal organic vapor phase epitaxy on a first selective growth area defined by a first mask pattern provided in the active region except in the passive region. The first mask pattern has a variation in width along the waveguide direction. The epitaxial layers are simultaneously and non-selectively grown on the entirety of the passive region by metal organic vapor phase epitaxy and epitaxial layers having a mesa structure in the active region and a plane structure in the passive region are formed. A cladding layer having a ridged structure is selectively grown by a metal organic vapor phase epitaxy on a second selective growth area defined by a second mask pattern provided in both the active and passive regions. The second mask pattern has a constant width. In the active region the ridged cladding layer completely embeds the mesa structure epitaxial layers and in the passive region the ridged cladding layer is provided on the plane structure epitaxial layers.