Published online by Cambridge University Press: 10 February 2011
Polarization independent quantum well (QW) materials operating under electroabsorption effect in optical switching and modulation devices are of intense interest recently. This is a theoretical analysis of the optical properties of strained InGaAs/InP QWs. The method of composition modification based on interdiffusion will be introduced to merge the heavy- and light- hole states in order to achieve polarization insensitivity. Results presented here show that the diffused QWs with and without as-growth tensile strain can both serve in polarization independent electro-absorption requirements. With a suitable design in the interdiffused QW materials, the optical polarization independence can operate from 1.465 to 1.540 μm (tunability of 75 nm) with a maximum absorption change of 2000 cm−1. In the case studied here, over 75% reduction in the required as-growth tensile strain is achieved as compared with the conventional rectangular QWs. This provides us with a simpler way to achieve high strain optical polarization independence through interdiffusion.