Polarization-dependent diffraction efficiency of a photorefractive volume grating and suppression of this efficiency.
Polarization-dependent diffraction efficiency of a photorefractive volume grating and suppression of this efficiency.
复制标题
DOI：
10.1364/ao.44.003013
复制
发表时间：
2005-05
期刊：
影响因子：
1.9
通讯作者：
Jianlin Zhao;Jifeng Li;Hongli Xiang;Jianglei Di
中科院分区：
文献类型：
--
作者：
Jianlin Zhao;Jifeng Li;Hongli Xiang;Jianglei Di
从单轴晶体的折射率椭球角度出发，从理论上分析了体光栅的衍射效率与读出光束偏振态之间的关系。折射光束的方向和相应的折射率调制都会因偏振态的变化而改变。在读出光束的偏振状态下，这可能导致体光栅的衍射效率发生强烈变化。各向异性晶体中体光栅的这种与偏振相关的衍射效率对于某些应用来说是极其不利的。提出了一种使用双体光栅抑制偏振相关衍射效率的方法，并演示了 LiNbO3:Fe 晶体的实验。实验结果表明，该方法可以很好地抑制体光栅偏振相关的衍射效率。此外，双体光栅的衍射特性几乎与读出光束的偏振态无关。根据折射率调制和偏振状态之间的关系计算衍射峰的相对值。实验值与理论分析吻合良好。
In terms of refractive-index ellipsoid of a uniaxial crystal, the relationship between the diffraction efficiency of a volume grating and the polarization state of a readout beam is theoretically analyzed. The direction of a refractive light beam and the corresponding refractive-index modulation will both be changed by a variation of the polarization state. In the polarization state of the readout beam, which may lead to a strong variation in the diffraction efficiency of the volume grating. This kind of polarization-dependent diffraction efficiency of a volume grating in an anisotropic crystal is extremely disadvantageous for some applications. A method to suppress the polarization-dependent diffraction efficiency by use of double volume gratings is presented, and experiments with LiNbO3:Fe crystal are also demonstrated. The experimental results indicate that this method can well suppress the polarization-dependent diffraction efficiency of a volume grating. Furthermore, the diffraction properties of the double volume gratings are almost independent of the polarization state of the readout beam. The relative values of the diffraction peaks are calculated on the basis of the relationship between index modulation and the state of polarization. The experimental values are in good agreement with the theoretical analyses.