Wang Jyun-Ruei, Lee Chia-Rong, Lee Mei-Ru, Fuh Andy Y G
Department of Physics, National Cheng Kung University, Tainan 701, Taiwan, China.
Opt Lett. 2004 Jan 1;29(1):110-2. doi: 10.1364/ol.29.000110.
We report on the photorefractive effect induced by a polarization grating in the presence of dc voltage in a dye-doped liquid-crystal (DDLC) film. The writing beams are two orthogonally (left- and right-circularly) polarized laser beams that create a spatially polarization-modulated interference field with constant intensity. The photorefractivity is ascribed to the absorption anisotropy of the azo dye. The unique dichroism of a DDLC cell causes a spatial variation in the absorption of light in response to a polarization-modulated interference field. Such a variation establishes a space-charge field in the presence of dc voltage, generating photorefractivity. Two-beam couplings were also verified and measured dynamically during the formation of the photorefractive grating in this study.
我们报道了在掺杂染料的液晶（DDLC）薄膜中，直流电压存在时极化光栅诱导的光折变效应。写入光束是两束正交（左旋和右旋圆）偏振激光束，它们产生具有恒定强度的空间偏振调制干涉场。光折变效应归因于偶氮染料的吸收各向异性。DDLC 单元独特的二向色性导致光吸收随偏振调制干涉场发生空间变化。这种变化在直流电压存在时建立起空间电荷场，从而产生光折变效应。在本研究中，还在光折变光栅形成过程中动态验证并测量了两束光的耦合。
