SENSITIVITY OF OPTIMIZATION OF MIDINFRARED INAS INGASB LASER ACTIVE REGIONS TO TEMPERATURE AND COMPOSITION VARIATIONS/

We calculate the temperature dependence of the threshold current densi ty J(th) in optimized (minimal J(th)) and unoptimized InAs/InGaSb supe rlattices. We find that the threshold current density of the unoptimiz ed superlattice is well described by J(th)proportional to e(T/T0), wit h T-0 similar to 32 K from 25 to 275 It. This is the first microscopic calculation for these superlattices which indicates that J(th) is wel l described by an empirical exponential form. In contrast, the thresho ld current density of the optimized superlattice is not well parametri zed by a characteristic temperature To. This superlattice is only opti mized between 250 and 350 K, due to the sharp structure of the intersu bband absorption spectrum, We also consider the effect on J(th) Of unc ertainties in layer thicknesses, (C) 1998 American Institute of Physic s.