Far-infrared subpicosecond transient grating measurement of electron cooling in indium arsenide

Summary form only given. Compared with GaAs, little is known about hot-electron dynamics in narrow-gap semiconductors like InAs. In these materials the conduction band is much more strongly nonparabolic, and both the effective electron mass and the electron-phonon coupling constant are smaller compared with values for GaAs. To study hot-electron dynamics in the conduction band of these materials, ultrashort mid- or far-infared pulses are necessary to avoid the unwanted creation of electron-hole pairs by interband one-, two-, or even three-photon excitation. Here, we show results of transient-grating experiments in n-type InAs in which we time-resolve the ultrafast cooling of a heated electron distribution using intense subpicosecond far-infrared pulses.