Patent ID: 7158291

Claim:
A semiconductor optical amplifier comprising: a substrate; a first gain section, disposed on said substrate; a second gain section, disposed on said substrate and adjacent to said first gain section; a residual cladding layer disposed above said first gain section and said second gain section, wherein said residual cladding layer has a first thickness over said first gain section, and a second thickness over said second gain section, said first thickness being different than said second thickness, wherein said first thickness of said residual cladding layer is selected to cause transverse electric (TE) light passing through said first gain section to experience a greater gain than transverse magnetic (TM) light passing through said first gain section; and wherein said second thickness of said residual cladding layer is selected to cause said TM light passing through said second gain section to experience a greater gain than said TE light passing through said second gain section.