De Sio Luciano, Tabiryan Nelson, Bunning Timothy J
Opt Express. 2015 Dec 14;23(25):32696-702. doi: 10.1364/OE.23.032696.
The formation and characterization of a switchable volume reflective element fabricated from a polymer liquid crystal (LC) polymer slice (POLICRYPS) structure by holographic photopolymerization at high temperature (65 °C) using a photosensitive/nematic liquid crystal prepolymer mixture is reported. The submicron Bragg structure formed consists of periodic continuous polymeric walls separated by periodic LC channels. The phase separated NLC self-aligns in a homeotropic alignment between the polymer walls as indicated by polarizing optical microscopy analysis (Maltese cross). The resulting periodic grating structure results in a Bragg reflection notch upon illumination with white light due to the periodic variation in refractive index. Electro-optical experiments realized through in-plane electrodes and temperature experiments confirm that the multilayer structure acts as a Bragg mirror whose reflection efficiency can be controlled by either a small (~3V/µm) electric field or temperature.
报道了通过使用光敏/向列型液晶预聚物混合物在高温（65°C）下进行全息光聚合，由聚合物液晶（LC）聚合物片（POLICRYPS）结构制备的可切换体积反射元件的形成和表征。形成的亚微米布拉格结构由周期性连续的聚合物壁和周期性的LC通道分隔而成。相分离的向列型液晶在聚合物壁之间以垂直排列方式自对准，这通过偏振光学显微镜分析（马耳他十字）得以表明。由于折射率的周期性变化，所得到的周期性光栅结构在白光照射下会产生布拉格反射陷波。通过平面内电极实现的电光实验和温度实验证实，该多层结构充当布拉格镜，其反射效率可通过小电场（约3V/μm）或温度来控制。
