Bulk Photovoltaic Effect in Gyrotropic Crystals

The effect of optical activity on the linear and circular bulk photovoltaic effect in crystals without a center of symmetry is investigated. It is shown that there is a phase shift of the linear photovoltaic current J^L, which is opposite for the right- and left crystals, and a change in modulus. The circular photovoltaic current J^C does not change in phase in dependence of the optical activity value but depends on the absorption and circular dichroism. The dependences of the J^L current on the polarization of incident light are calculated taking into account the optical activity for the right and left Bi₁₂SiO₂₀, Bi₁₂GeO₂₀, and Bi₁₂TiO₂₀ crystals (class 23). Similar calculations of J^L were performed for the right crystals Pb₅Ge₃O₁₁ (class 3); La₃Ga₅SiO₁₄ with impurities of Pr, Fe, Cr, and Mn, Ca₃TaGa₃Si₂O₁₄ (class 32); and Er(HCOO)₃⋅2H₂O (class 222) in the case where light propagates in the direction of the optical axis. Examples of the J^C value for crystals Pb₅Ge₃O₁₁; La₃Ga₅SiO₁₄ with of Co, Cr, and Fe impurities; and α-HgS (class 32) are given. It is shown that consideration of optical activity is necessary when studying the photorefractive effect in crystals.