Diffractional divergence of radiation from heterostructure injection lasers based on quaternary solid solutions, isoperiodic with GaSb

The paper examines the problems of optical limiting and radiation divergence (in the plane perpendicular to the active layer) in injection lasers based on twosided heterostructures in the solid solution systems AlGaAsSb/GaSb, AlGaAsSb/GaInAsSb/GaSb in the IR range (particularly at wavelengths of 1.55, 1.775, and 1.93 microns). The diffractional divergence angle for the lower mode of the waveguide is calculated as a function of waveguide thickness. Good agreement was found between theoretical calculations and experimental data on the radiation divergence in the heterostructure lasers in the 1.75-1.78 micron range. A modified single-oscillator method was used to calculate the refractive indices of AlGaAsSb and GaInAsSb.