Polarization-insensitive quantum-well semiconductor optical amplifiers

Theoretical modeling and fabrication of polarization-insensitive semiconductor optical amplifiers that use a multi-quantum-well structure as the gain media are reported. Polarization insensitivity of gain is achieved through the introduction tensile strain into the quantum wells. Gain calculations, using the k/spl middot/p method, were performed to obtain the required amount of tensile strain to obtain polarization insensitivity over a wide energy spectrum. Fabricated amplifiers show a polarization-insensitive (<1 dB) spectral width of 10 nm at 1300 nm in the InGaAsP/InP system, 15 nm at 1300 nm in the AlInGaAs/InP system, and 40 nm at 1550 nm in the AlInGaAs/InP system.