Influence of anisotropic deformation on the radiative characteristics of GaInAsP/InP injection lasers. I. Lasing threshold, polarization, and wattampere characteristic

A study was made of the relationship between the radiative characteristics of GaInAsP/InP lasers (λ~1.08–1.61μ, 300K) and anisotropic deformation of the active layer that occurs either as a result of external compression or due to mismatch of lattice periods in heterojunctions. The strain can be estimated to within ±10% from an analysis of the spectra of the degree of linear polarization of the spontaneous emission. When the lattice periods are completely matched, the temperature parameter T₀ and the differential efficiency pass through a minimum and the threshold current density passes through a maximum. Consequently, the radiative characteristics of laser diodes can be improved by optimizing the stressed state of the active layer. Deviations of the relative mismatch of the lattices in the laser heterostructures give rise to a spread of the radiative characteristics as a result of their sensitivity to the level of internal residual stresses.