Integrated semiconductor laser

Abstract

An integrated phase-locked semiconductor laser wherein a plurality of waveguide paths extend in parallel to each other. A current blocking layer is formed on one of opposite major surfaces of a semiconductor substrate and is divided into a plurality of regions by a plurality of stripe-like channels. Each of the channels has a depth which reaches at least the above-mentioned major surface of the substrate. A first cladding layer covers the surface of the current blocking layer and those regions of the substrate which are exposed to the channels. A waveguide layer is deposited on the first cladding layer and has a surface opposite to the first cladding layer which is substantially flat. An active layer, a reflecting layer, a second cladding layer and a cap layer are deposited one upon another on the waveguide layer layer. The waveguide layer has an effective refractive index which sequentially decreases in the order of first regions individually associated with the plurality of channels, second regions individually associated with interchannel regions each intervening between nearby channels, and third regions located at opposite sides of the plurality of channels relatively to each other.