CARRIER CAPTURE AND ESCAPE IN MULTISUBBAND QUANTUM-WELL LASERS

Carrier capture and escape processes between quantum wells and barrier s via carrier-polar optical phonon interactions are theoretical studie d in multisubband quantum well structures. We find that carriers in ea ch subband have their own minimum capture and escape times when the en ergy difference between the band edges of the subbands and the barrier is equal to the energy of a longitudinal optical phonon. Our results indicate that carrier escape time is more quantum well structure-depen dent while carrier capture time is less structure-dependent. Explicit forms for calculating carrier capture and escape times are given which are crucial for designing the quantum well structures with optimal ca pture or escape efficiencies.