Ultrafast changes of optical properties of semiconductors at wavelength near the edge of interband absorption after excitation by femtosecond laser pulse

Abstract

In this work, we have studied theoretically the dynamics of optical properties of silicon and gallium arsenide at the wavelengths near the edge of interband absorption after excitation by an intense femtosecond laser pulse. It was shown that the transmittance of a semiconductor plate should rapidly increase during electron-phonon relaxation. This effect can be used to experimentally determine the electron-phonon relaxation time for band gap materials. The optimal conditions for the experimental observation of the effect of ultrafast enlightenment of semiconductors were defined.