Research On Sensoring Mechanism Of Liquid-crystal Photonic Crystal Fiber

Photonic crystal fiber is also called micro-structure fiber. Is is a new type fiber which have emerged in the last few years in the 20th century.Its character of transmitting light can be controlled by changing the size,distance, queueing discipline of air holes,and fill the air holes with gas,liquid and so on. With the devolopment of photonic crystal fiber, liquid crystal as a filled stuff,have so many optical advantage that it attracts researchers a lot. So far, liquid crystal filled-total internal reflection photonic crystal fiber can be used to make thermol-optical switch, electrically tunable optical switch and all optical-modulation devices and so on.Filling liquid crystal into photonic bandgap fiber can modulate the bandgap of the fiber or make all a solid photonic band gap fiber,This is also a trend of the photonic crystal fiber.The theoretical study focus on the character of transmitting light after filling the liquid crystal and studying it through numerical simulation. Main content lies in aspects below:(1) Briefly introduced the basic concept and the type of photonic crystal fiber. It had a detailed review of the research of liquid crystal filled photonic crystal fiber from home and abroad since the year 2000. It also gives the prospect on photonic crystal fiber sensor for application in the future.(2) Briefly introduced the optical character,and look photonic crystal molecule as uniaxial crystal, introduced anisotropy index of refraction of uniaxial crystal. Finite element mathod is stated.(3) According to function between index of refraction of liquid crystal and temperature,we get the relation between effective index of fundamental mode,effective mode area and temperature, dutycycle,and calculate the waveguide dispersion under different temperature.(4) According to function between index of refraction of liquid crystal and electric field Strength, we get the relation between effective index of fundamental mode,effective mode area and electric field strength, dutycycle. I find several cutoff wavelength wavelength under different voltage.This study provid theoretical foundation to use temperature and electric field to control light in photonic crystal fiber. It provid some meaningful Conclusion to the PCF sensor in the furture.