Computational Analysis of Optical Gain Characteristics of Al0.15In0.22Ga0.63As/GaAs Nano Heterostructure

Abstract

This paper reports the computational analysis of optical gain characteristics of Step Index based nano-scale heterostructure comprising of a single quantum well of material composition Al0.15In0.22Ga0.63As sandwiched between the barriers of material composition Al0.2Ga0.8As followed by claddings of Al0.6Ga0.4As material. The complete structure is supposed to be grown on GaAs substrate. Apart from the lasing properties like optical gain, modal gain, anti-guiding factor, we have also studied the energy band structure along with conduction and valence band envelope functions and band offsets. By theoretical simulation, we have determined the behaviour of quasi-Fermi levels in both the conduction and valence bands. These properties have been studied in TE (Transverse Electric) polarization mode in general and then, in the latter part of the paper, it has been compared with TM (Transverse Magnetic) mode as well. The optical gain has been found to be maximum at a lasing wavelength of 0.843 micrometer for TE mode and at 0.792 micrometer in TM mode which suggest lasing in NIR region. Moreover, the optical gain of nano-heterostructure based on Al0.15In0.22Ga0.63As/GaAs has been compared with the In0.71Ga0.21Al0.08As/InP nanoheterostructure.