Lee Chun-Hong, Chen Ching-Hsiang, Kao Chia-Lung, Yu Chin-Ping, Yeh Szu-Ming, Cheng Wood-Hi, Lin Tsung-Hsien
Department of Photonics, National Sun Yat Sen University, Kaohsiung, Taiwan 804, ROC.
Opt Express. 2010 Feb 1;18(3):2814-21. doi: 10.1364/OE.18.002814.
This work demonstrates photo alignment and electrical tuning effects in photonic liquid crystal fiber (PLCF). Applying voltages of 0 approximately 130V and 250 approximately 400V shifts the short and long wavelength edges of the transmission bands by about 45 nm and 74 nm toward longer wavelengths, respectively. An electro-tunable notch filter is formed in the PLCF without the use of gratings. The range of tunability of the notch filter is around 180 nm with an applied voltage of 140 approximately 240 V. This photo-induced alignment yields a permanently tilted LC structure in PCF, which reduces the threshold voltage, and can be further modulated by electric fields. The polarization dependent loss and fast response time of photo-aligned PLCF is also demonstrated. The finite-difference frequency-domain method is adopted to analyze the shift of the transmission bandgap, and the simulation results are found to correlate well with experimental data.
这项工作展示了光子液晶光纤（PLCF）中的光对准和电调谐效应。施加0至130V以及250至400V的电压时，传输带的短波长和长波长边缘分别向更长波长方向移动约45nm和74nm。在不使用光栅的情况下，在光子液晶光纤中形成了一个电可调谐陷波滤波器。在施加140至240V电压时，陷波滤波器的可调谐范围约为180nm。这种光致对准在光子晶体光纤中产生了一个永久倾斜的液晶结构，降低了阈值电压，并且可以通过电场进一步调制。还展示了光对准光子液晶光纤的偏振相关损耗和快速响应时间。采用有限差分频域方法分析传输带隙的移动，发现模拟结果与实验数据具有良好的相关性。
