Linear photoelasticity coefficients of quantum-well layer structures near resonances of quasitwo-dimensional excitons calculated allowing for the finite well width

An analytic expression for the linear photoelasticity coefficients of quantum-well layer structures is derived for frequencies near resonances of quasitwo-dimensional excitons allowing for the finite quantum well width. The photoelasticity coefficients are calculated for GaAs/Al 0.28 Ga 0.72 As superlattices at the long-wavelength edge of a quasitwo-dimensional exciton resonance. It is shown that these coefficients are greater than the corresponding quantities in the off-resonance case of a bulk crystal. It is suggested that in this frequency range one could use a superlattice as a material having a high value of the photoelasticity coefficient