[1] Makino T. Analytical formulas for optical gain of quantum well.I EEE Journal of Quantum Electronics,1996,32(3): 493
[2] Manasreh M O, Szmulowicz F, Fischer D W,et al. Intersubband infr ared absorption in a GaAs/Al0.3Ga0.7As quantum well structure.Appl .Phys.Lett.,1990,57(7):1790