Intrinsic Piezobirefringence of Ge, Si, and GaAs

摘要: The stress-induced birefringence of Ge, Si, and GaAs its dispersion in the region immediately below fundamental absorption edge are reported. measurements were performed at room temperature for stresses along [001] [111] directions up to 5 \ifmmode\times\else\texttimes\fi{} ${10}^{9}$ dyn/${\mathrm{cm}}^{2}$. carrier concentration samples ($n$ type) was low enough (\ensuremath{\le} ${10}^{16}$ ${\mathrm{cm}}^{\ensuremath{-}3}$) make free-carrier piezobirefringence negligible spectral our measurement ($\ensuremath{\lambda}\ensuremath{\le}2.5$ \ensuremath{\mu}). data Ge analyzed using an interband one-electron model optical constants, which includes effects ${E}_{0}$, ${E}_{0}+{\ensuremath{\Delta}}_{0}$, ${E}_{1}$, ${E}_{1}+{\ensuremath{\Delta}}_{1}$, ${E}_{2}$ gaps. silicon fitted with a centers 4.4 eV (${E}_{2}$) 3.2 ($E_{0}^{}{}_{}{}^{\ensuremath{'}}$ ${E}_{1}$). These models provide good description experimental have some bearing upon question accuracy deformation potentials determined from data.