Two-photon spectroscopy of GaAs

Publisher Website
Google Scholar
Abstract
Two-photon absorption spectra of GaAs were obtained using photoconductivity techniques. At zero magnetic field, the spectrum has a photon energy (ℏω) dependence of (2ℏω–Eg)3/2 just above the energy band gap (Eg), and can be described without considering exciton enhancement effects. Oscillatory behavior in the photoconductive response at zero field as a function of incident two-photon energy has been observed and shown to be due to the interaction of the photoexcited electrons and longitudinal optical phonons. At high magnetic fields, the spectra are quantitatively interpreted in terms of a modified Pidgeon–Brown energy band model.