Patent ID: 6862394

Claim:
A tuning region of a semiconductor optical device comprising: a substrate; a first cladding layer over said substrate; a waveguide layer provided over at least a portion of said substrate and said first cladding layer, at least a portion of said waveguide layer having a concentration of recombination centers in the range of about 1×10 16 cm −3 to about 1×10 18 cm −3 , wherein said recombination centers are formed by doping said at least a portion of said waveguide layer with impurity atoms selected from the group consisting of iron, chromium, manganese and copper; a second cladding layer, said first and second cladding layers forming a p-n junction around said waveguide layer; and electrical contacts to said first and second cladding layers for providing a bias of said p-n junction for the purpose of injecting carriers into said waveguide layer.