Free carrier absorption in free standing quantum well nanostructures

A calculation of free carrier absorption in a free-standing quantum well (FSQW) nanostructure due to the electron interaction with confined acoustic modes described by elastic continuum model is presented. Numerical results are given for GaAs FSQW structure for the dependence of absorption coefficient on photon frequency electron temperature and thickness of the nanostructure. The oscillatory dependence of absorption coefficient on thickness of the FSQW nanostructure is attributed to the energy dispersion of confined acoustic modes which is in contrast with the calculations based on bulk description of acoustic phonons.