PHOTONIC CRYSTAL OPTICAL ELEMENT

摘要

An active area lamination portion, in which an active area core layer having an active layer is laminated between an active area upper clad layer and an active area lower clad layer, is formed to have a plurality of pores periodically arrayed in the direction of the principal plane of the active area core layer from the active area upper clad layer to a position deeper than the lower face of the active area core layer, excepting a linear defect portion for guiding a light of a predetermined wavelength, thereby to prepare an active area unit having a photonic crystal optical waveguide. A passive area lamination portion, in which a passive area core layer is laminated between a passive area upper clad layer and a passive area lower clad layer, is formed to prepare a passive area unit having a passive optical waveguide to be optically connected with the photonic crystal optical waveguide. The active area unit and the passive area unit thus prepared are laminated on a semiconductor substrate. The effective refractive index of the lamination structure of the active area lamination portion is higher than the effective refractive index of the lamination structure of the passive area lamination portion, and the active layer has a gain at a zero group-velocity point, which is located on the higher-frequency side on the dispersion curve of the photonic crystal optical waveguide. Thus, it is possible to provide a photonic crystal optical element, which is high in power efficiency and easy in manufacture.