Strong intersubband absorption in a single doped pseudomorphic InAs/In/sub 0.53/Ga/sub 0.47/As/AlAs quantum well on InP

Quantum well infrared intersubband (QWII) absorption in a single doped InAs/InGaAs/AlAs quantum well (SQW) is discussed. Absorption as large as 8% was observed for SQWs measured in a waveguide geometry. The SQW absorption shows relatively little polarization dependence. Strongly polarized infrared absorption, seen in the spectra arising from transitions between the occupied Fe level and the ionized Si donor level at the InGaAs/Fe:InP interface, and multiple phonon excitation, observed in the Fe-doped semi-insulating InP substrate, are described.<
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