An extensive study on simple and GRIN SCH-based In0.71Ga0.21Al0.08As/InP lasing heterostructures

Abstract

In this paper, we have proposed a model for simple and graded index (GRIN) separate confinement heterostructure (SCH)-based In0.71Ga0.21Al0.08As/InP single-quantum-well lasing heterostructures and studied the energy band structure along with conduction and valence band envelope functions and band offsets. Under theoretical simulation, we have determined the behavior of quasi-Fermi levels in both the conduction and valence bands. Moreover, we have also calculated various important lasing characteristics and the optical gain of the lasing structure as a function of lasing wavelength in transverse electric (TE) and transverse magnetic (TM) modes. For both types of lasing structures, optical gain in the TE mode has been reported to be larger than that in the TM mode. In the TE mode the maximum optical gain for simple and GRIN structures has been achieved at lasing wavelengths of 1.55 and 1.38 μm, respectively, while in the TM mode the values of maximum optical gain for both types of the structures are found to be the same, i.e. at 1.34 μm. Since the optical attenuation within the waveguide is found to be minimum at 1.55 μm, the simple SCH-based In0.71Ga0.21Al0.08As/InP lasing structures are suggested to be preferred to the GRIN SCH-based lasing structures of InGaAlAs/InP material systems.