Abstract

We observed photoinduced intersubband transition and an interband bleaching in undoped HgCdTe Multiple Quantum Well (MQW) as a function of temperature.^[1,2] The polarization selection rule for the intersubband transition (X polarization forbidden) is clearly seen. We have good fittings for both the interband bleaching and intersubband transition spectra assuming a band filling bleaching mechanism and different “in plane” effective masses for the first and second electron subbands. The energy positions can be calculated within 5 meV using a non parabolic model.^[1] The photogenerated carrier density can be estimated from the interband bleaching spectra and checked with the pump light intensity at the sample. The ratio between the intersubband and interband transition areas is independent of the temperature, carrier dansity and optical path and can be used to estimate the intersubband oscillator strength.

© 1992 IQEC