Two-photon magnetoabsorption spectroscopy inn-InSb with cw CO2lasers

High-resolution two-photon magnetoabsorption (TPMA) spectra are obtained for $\overrightarrow{\mathrm{e}}\perp \overrightarrow{\mathrm{B}}$ and $\overrightarrow{\mathrm{e}}\left|\right|\overrightarrow{\mathrm{B}}$ polarizations in the Voigt geometry. The use of cw C${\mathrm{O}}_2$ lasers and a sensitive photoconductivity technique have allowed the observation of many new TPMA transitions. A modified Pidgeon-Brown energy-band model, along with the usual spherical two-photon selection rules, explains most of the observed transitions. The temperature dependence of the energy gap is deduced from an analysis of the TPMA spectra at various temperatures.