Multi-dimensional photoalignment of photoreactive polymer liquid crystals and generation of anisotropic photonic devices

实现小型数码相机的微型化、发展高对比度信息显示和高密度光存储的需求日益增长，激发了人们对高功能化光学器件的兴趣。衍射光学器件对于实现光学存储器件、集成光学器件、薄膜光学滤波器等数值光学功能具有重要意义。通过将光敏材料如光聚合物暴露于干涉光，可以制造衍射光学器件。这种光栅可以控制光的传播方向，可用于光电设备。为了使衍射光学器件在光学信息处理系统中发挥更大的作用，需要对光栅进行更高的功能化改造。人们相信，如果使用各向异性而不是各向同性材料的光栅，然后偏振可控衍射器件可以开发。在本研究中，我们利用光取向技术成功地制备了几种高度功能化（偏振）的光学器件，即1）偏振复用记录，2）偏振转换光栅，3）液晶光栅单元，4）三维全息器件。

The increasing need to realize the very small scale of digital compact camera, develop the high-contrast information display and high-density optical memory, has stimulated interest in highly functionalized optical devices. Diffractive optical devices are of great importance for realizing numerical optical functions such as optical memory devices, integrated optical devices, and thin film optical filters. It is possible to fabricate diffractive optical devices by exposing light sensitive materials such as photopolymers to interference light. The resulting gratings can control light propagation directions and can be used in optoelectronic equipments. In order for diffraction optical devices to play more important roles in optical information processing systems, higher functions should be added to optical gratings. It is believed that if anisotropic rather than isotropic materials for optical gratings were used, then polarization controllable diffractive devices could be developed. In the preset study we have been successfully fabricate several kinds of highly-functionalized (polarized) optical devices by using the photoalignment technique, i.e. 1) polarization multiplex recording, 2) polarization converted gratings, 3) liquid crystalline grating cells, and 4) three-dimensional holographic devices.