OPTICAL SEMICONDUCTOR DEVICE

摘要

Disclosed is an optical semiconductor device comprising: a lower cladding layer (12) having a first conductivity type; an active layer (14) arranged on the lower cladding layer (12) and composed of a plurality of quantum dot layers (51-55) stacked on top of one another and having a plurality of quantum dots (41); and an upper cladding layer (18) arranged on the active layer (14) and having a second conductivity type which is opposite to the first conductivity type.  The plurality of quantum dot layers (51-55) have different quantum dot densities.