Transient mid-ir picosecond spectroscopy of indium arsenide at room temperature: Evidence of spectral hole burning due to nonthermalized carriers.

Abstract

Spectral hole burning in the interband absorption continuum of InAs has been studied using pump radiation (with photon energy 32--57 meV above the band edge and intensity \ensuremath{\approxeq}${10}^{7}$ W/${\mathrm{cm}}^{2}$) generated by a picosecond midinfrared double-resonance pump-probe spectrometer. The quasi-steady-state spectral holes observed had depths which followed the instantaneous pump intensity and typical widths of \ensuremath{\approxeq}300 ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}1}$. The evolution of the shape of the spectral holes is correlated with the primary carrier scattering processes and an analysis of their widths and depths gives values of the carrier-carrier thermalization and dephasing times ${\mathit{T}}_{1}$\ensuremath{\approxeq}65 fs and ${\mathit{T}}_{2}$\ensuremath{\approxeq}40 fs, respectively.