Intersubband absorption in a modulation-doped Ga0.47In0.53As/Al0.48In0.52As multiple quantum well structure

Abstract

We observe strong intersubband absorption at a wavelength of 8.4 μm in an n-type modulation-doped Ga0.47In0.53As/Al0.48In0.52As multiple quantum well structure with a well thickness of 8.2 nm. An oscillator strength of the corresponding dipole transition of 21.0 is measured. The dependence of the intersubband absorption on the polarization of the incident light and on lattice temperature is investigated in detail.