Two-photon absorption in multi quantum well structures

The two-photon absorption coefficient in GaAs/Ga 1-x Alx As semiconductor heterostructure is calculated. Here we take into account the finiteness of quantum well depth and band structure features of materials. The polarization and frequency dependence of two-photon absorption is analysed. It is shown, that for small quantum well depths the number of possible optical transitions in the well reduces. Moreover, some of transitions, which exist in infinite quantum well, are missing at all. 13 refs