EFFECTS OF INTERDIFFUSION ON THE POLARIZATION-DEPENDENT REFRACTIVE-INDEX OF A STRAINED INGAAS GAAS QUANTUM-WELL/

The polarization dependent refractive index of disordered, strained In GaAs/GaAs single quantum wells is calculated using the complex dielect ric function, taking into consideration the contributions from the GAM MA, X, and L Brillouin zones. At longer wavelengths the refractive ind ex decreases as the extent of disordering increases, resulting in a po sitive refractive index step when the lateral confining regions are mo re extensively disordered. The structure also exhibits birefringence i n the quantum well band edge to barrier band-edge wavelength range whi ch decreases with interdiffusion. The refractive index is polarization independent outside this wavelength range. Interdiffusion extends thi s zero birefringence to shorter wavelengths.