Research On Multicore Photonic Crystal Fiber Laser And Liguid Crystal Doped Photonic Crystal Fiber Sensor

The photonic crystal ifber (PCF)，with simple and flexible designed structure, aswell as many unique properties compared to traditional ifbers, has been paid closeextensive attention. Nowadays, more and more studies were made on the PCF laserand the PCF sensor. In this dissertation，the coherent combination of the multicorePCF laser theory were studied and expeirmentally researched; the temperature sensingof liquid crystal infiltrated PCF was simulated and analyzed.The key technology and innovations of this dissertation can be summarized asfollows:1.The mode coupling pirnciple and the supermode distirbution of the multicorePCF laser were analyzed in this dissertation. The mode distirbution of18-core and19-core fiber and18-core PCF was simulated and analyzed by COMSOL.2.The supermode difrfaction analysis method was introduced. Based on theoptimized algorithm to Fresnel integral, the difrfaction distirbution of the18-core PCFwas calculated and analyzed. The self-imaging theory of Talbot cavity was introduced.The in-phase supermode selection of the18-core PCF was calculated based on thistheory. Rate equation of the multi-core PCF was established and used for transversesupermode competition analysis in the butt-contact mirror cavity and the Talbotcavity structure.3.The in-phase transverse supermode selection of the18-core PCF laser wasexpeirmentally researched. The pumping coupling system was designed and simulated.The coupling efficiency was significantly improved. The18-core PCF laser wasexpeirmentally researched by near ifeld proifler, using the butt-contact mirror, theTalbot cavity, and the pinhole with folded cavity. Coherent combination of the18-core PCF cw laser was firstly realized in laboratory. This is an importantsigniifcance for the multi-core PCF laser coherent combination technology.4.The optical character of the liquid crystal (LC) was investigated in thisdissertation. The refraction index performance was analyzed. The temperature anddispersion behavior of the E7liquid crystal was presented. To the E7LC material, theoptical parameters’ temperature characters in three kind of liquid crystal doped PCFwith different air-hole filling ratio were analyzed and calculated. The dispersion performances of liquid crystal infiltered PCF were given under different temperatures.