A study of linear dichroism induced by uniaxial strain in silicon crystals

Spectral characteristics of linear dichroism in uniaxially-strained silicon crystals in the region of edge absorption were studied using the polarization-modulation technique. The fine structure of the spectra due to participation of acoustic and optical phonons in interband transitions caused by absorption of linearly polarized radiation was observed. The spectral characteristics of induced absorption-coefficient anisotropy, revealing the phonon-related features, were determined from the combination of transmission and dichroism spectra. A phenomenological description of polarization-modulation measurements is considered; it is shown that the spectral dependence of the dichroism is given by the derivative of the transmission function with respect to the absorption coefficient.