Use of a Small Lattice Mis-matched Metamorphic Substrate to Extend the Wavelength Range of a Broadband, Polarization Insensitive Semiconductor Optical Amplifier

An InAs0.155P0.845 metamorphic substrate is used to increase the long-wavelength range of tensile strained quantum-wells used in polarization-insensitive semiconductor optical amplifiers. The peak emission of the amplified spontaneous emission occurs on the light-hole sub-band at wavelength longer than 1640 nm. In addition, the metamorphic substrate reduces the degree of lateral composition modulation seen by tensile strained semiconductor materials grown by molecular beam epitaxy.