Confinement factor and loss calculation of rectangular multiple quantum well waveguide

Modal analysis of rectangular multiple quantum wells (MQW) waveguides have attracted considerable interest for optimization of optoelectronic devices such as semiconductor lasers, electro-absorption modulators, and electro-optic devices. Previously we have investigated guided mode characteristics in rectangular MQW waveguides using the combination of effective index method (EIM) and scanning angle method (SAM). Though the EIM-SAM does not include the effect of complex refractive index, one can reasonably assume that the modal intensity distribution in the MQW active waveguide is very similar to that in the passive waveguide because the imaginary part of the refractive indices in the active region is typically small compared to the real part. Therefore, perturbation analysis for the loss calculation of a rectangular MQW waveguide can be used. In this paper, we show the method for calculating the modal power attenuation (or gain) coefficient of two-dimensional MQW waveguide structure from the optical confinement factor obtained by the EIM-SAM.