Photonic semiconductor device

A photonic semiconductor device comprising:

• a semiconductor substrate;
• a laser unit including a plurality of single wavelength semiconductor lasers, each single wavelength laser producing light of a respective and different wavelength and comprising an optical waveguide ridge including an active layer sandwiched by a pair of current blocking structures, each current blocking structure including, serially disposed with respect to said semiconductor substrate, first and second semiconductor layers;
• an output unit having a first waveguide layer, sandwiched by a first upper cladding layer and a first lower cladding layer, and outputting laser light produced by said laser unit;
• a combiner unit having a second waveguide layer sandwiched by a second upper cladding layer and a second lower cladding layer, and having a first end abutting said laser unit and a second end abutting said output unit, said semiconductor substrate carrying said laser unit, said output unit, and said combiner unit;
• and
• a burying semiconductor layer structure including said first and second semiconductor layers, said first semiconductor layer completely covering and burying said combiner unit and said second semiconductor layer completely covering said first semiconductor layer opposite said combiner unit.