偏振敏感材料中具有圆各向异性的偏振全息光栅

Polarization Holographic Grating with Circular Anisotropy Recorded in Polarization-Sensitive Materials

在向列相液晶中掺杂质量分数约0.2%的偶氮侧链型聚合物制成偏振敏感材料,使用正交圆偏振光记录了具有圆各向异性的一维偏振全息光栅,用线偏振光探测偏振全息光栅,得到正、负一级衍射光也为线偏振光,且偏振态与探测光和零级偏振态相互正交,可以运用琼斯矩阵理论加以解释。偏振全息光栅可由外加电场控制衍射级的变化,即在外加电场作用下,正、负一级衍射产生了90°的相位差。在频率6.05Hz、电压2.2V的外场作用下,衍射级的极值振荡变化。

The polarization-sensitive material is fabricated with nematic liquid crystal doped with 0. 2% （mass fraction） of azobenzene side-chain liquid-crystalline polymer, in which polarization holographic grating with circular anisotropy was recorded by two orthogonal circular-polarization light beams. It found that when the probe beam is linearly polarized, the ± 1 order diffraction beams are also linearly polarized with polarization direction perpendular to that of the probe light and the zero-order diffraction light. The experimental results are in good agreement with the theoretical expectation based on Jones matrix. The diffraction orders can be controlled by the applied electric filed, and there is 90°phase difference between the ±1 orders diffraction beams. When the frequency is 6.05 Hz and the applied voltage is 2.2 V, the extreme value of diffraction orders oscillates.