EXPERIMENTAL AND THEORETICAL DENSITY-DEPENDENT ABSORPTION-SPECTRA IN (GAINSB INAS)/ALGASB SUPERLATTICE MULTIPLE-QUANTUM WELLS/

A broadly tunable, ultrafast optical parametric oscillator is used to measure carrier-density-dependent absorption spectra in a 340-meV band gap (GaInSb/lnAs)/AlGaSb superlattice multiple quantum well structure . Similar structures have been implemented recently as the active regi on in midinfrared diode lasers. The measured spectra are compared with calculated spectra computed using a semiempirical eight-band superlat tice K.p model. The model provides good agreement with the experimenta lly observed spectral and density dependence of the absorption. These results provide confirmation that the model may be used for band struc ture engineering of optimized midinfrared laser active regions. (C) 19 98 American Institute of Physics.