Analysis of coupling effect on twin waveguides defined by ion-implanted AlGaAs/GaAs quantum wells

Abstract

An accurate model is presented for the analysis of ion-implanted AlGaAs/GaAs multi-quantum well symmetric and asymmetric twin waveguides. The modal propagation constants, modal indices and field profiles of the leading supermodes are solved numerically by using a quasi-vector method based on the Finite Difference method. Impurity induced disordering defined multi-quantum well twin waveguides are shown to have similar optical properties as conventional dielectric rib waveguides. They provide a more flexible control over the waveguiding and coupling characteristics by changing the diffusion time, the ion implant energy, the mask width, the waveguide separation, and the operating wavelength. By suitably varying these parameters, single-mode operation can be achieved, while the coupling length can be theoretically tuned from a few millimeters to a hundred meters, a difference in the order of lOs. Impurity induced disordering produced waveguide arrays are therefore highly recommended for integrated photonic IC realisation.