Liou Jia-hong, Chang Tin-hao, Lin Ta, Yu Chin-ping
Department of Photonics, Institute of Electro-optical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan.
Opt Express. 2011 Mar 28;19(7):6756-61. doi: 10.1364/OE.19.006756.
A novel light-controllable long-period fiber grating (LPFG) is demonstrated by making use of a PCF infiltrated with a photoresponsive liquid crystal (LC) mixture consisting of nematic LC molecules and light-sensitive 4-methoxyazobenzene (4MAB). With the aid of the photo-induced isomerization of 4MAB, the refractive index of the LC mixture can be modulated and the periodic index perturbation along the fiber can be achieved by exposing the PCF to a blue laser through a mask. The resonance wavelength and dip depth of the LPFG can be controlled by using different blue-laser irradiation time, numbers of period, and 4MAB concentrations. In addition, the photo-induced LPFG is erasable under green-laser illumination.
通过利用填充有由向列型液晶分子和光敏4-甲氧基偶氮苯（4MAB）组成的光响应液晶（LC）混合物的光子晶体光纤（PCF），展示了一种新型的光控长周期光纤光栅（LPFG）。借助4MAB的光致异构化，可以调制LC混合物的折射率，并且通过将PCF通过掩膜暴露于蓝光激光器，可以实现沿光纤的周期性折射率微扰。LPFG的共振波长和凹陷深度可以通过使用不同的蓝光激光照射时间、周期数和4MAB浓度来控制。此外，光致LPFG在绿光照射下可擦除。
