We report observations of a spectral dependence of the conductivity in 5 mol.% MgO doped LiNbO₃ single crystals with periodical domain structure (PDS) of stripe domains with charged domain walls during sub-bandgap illumination by probing laser beams. The photoinduced conductivity is manifested through a comparatively slow relaxation of the first-order Bragg electrooptical diffraction efficiency after application of an external electric field to the crystal. The relaxation rate connected with screening of the external field due to redistribution of the space charge over the conductive charged domain walls linearly increased in the initial stage with the probe beam intensity. The parameters of the effective photoinduced conductivity averaged over the PDS period that describe its dependence on the intensity decreased from 10.9⋅10⁻¹⁴ to 1.79⋅10⁻¹⁶ Ω⁻¹W⁻¹m as the wavelength of the probe beam increased from 457 to 980 nm.

我们报告了对 5 mol.% MgO 掺杂的 LiNbO _{3 中}电导率的光谱依赖性的观察在通过探测激光束进行亚带隙照明期间，具有带电畴壁的带电畴壁的条纹畴的周期性畴结构 (PDS) 的单晶。在对晶体施加外部电场后，一阶布拉格电光衍射效率的相对缓慢弛豫表明了光致导电性。由于空间电荷在导电带电畴壁上的重新分布，与外场屏蔽相关的弛豫率在初始阶段随探测光束强度线性增加。描述其对强度依赖性的 PDS 周期内平均有效光致电导率参数从 10.9⋅10 ^-14降至 1.79⋅10 ^-16  Ω ^-1 W^-1 m 随着探测光束的波长从 457 nm 增加到 980 nm。