Model of orthogonal two-wave mixing in photorefractive crystal of cubic symmetry with optical activity

We developed a physical model describing the process of two-wave vectorial mixing in optically active photorefractive crystal of cubic symmetry for an orthogonal scheme of interaction. Using the model, we calculated the two-wave interaction in a photorefractive crystal of bismuth silicate Bi₁₂SiO₂₀ having optical activity. We have determined conditions at that polarization changes don’t influence two-wave mixing. It was found that it is possible to define the parameters of the crystal and interacting waves for the quasi-polarization independence mode, when changes of interferometer output signal caused by polarization instability of the signal wave is reduced to a minimum (no more than 3%). We developed a physical model describing vectorial two-wave mixing in optically active, cubic-symmetry photorefractive crystals for an orthogonal interaction geometry. We apply the model to bismuth silicate (Bi₁₂SiO₂₀), an optically active photorefractive crystal. We further show that by appropriately selecting crystal and wave parameters, a quasi-polarization-independent regime can be achieved, in which interferometer output fluctuations caused by signal-wave polarization instability are minimized to no more than 3%.