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·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