Study On Polarization Maintaining Photonic Crystal Fiber And Its Application On Fiber Optic Gyroscope

Fiber optic gyroscope(FOG) based on photonic crystal fiber shows important application prospects on strong radiation environments such as outspace and nuclear reactor.This dissertation is supported by the National Natural Science Foundation of China under Grant No.60577034.In this dissertation,polarizaition maintaining photonic crystal fiber(PM-PCF) with high polarization stability and the characteristics of fiber optic gyroscope(FOG) based on this PM-PCF are investigated.The main innovative achievements are listed as follows:(1) A new theoretical analysis model of PM-PCF is established based on three-dimensional full-vector beam propagation method(3D-FV-BPM).The effects of transverse variation and longitudinal variation of air-holes with three type situations (diameter variation,non-circle variation and position offset) on birefringence and polarization stability are analyzed in detail.(2) A novel near-elliptic inner-cladding PM-PCF(NEIC-PCF) is proposed and its polarization characteristics and polarization stability are analyzed.Compared with near-Panda cladding photonic crystal fiber(NPC-PCF),this fiber shows outstanding polarization characteristics and polarization stability.Furthermore,an improved NEIC-PCF structure with small mode area(SMFD-NEIC-PCF) is designed for FOG. This new structure can realize simple coupling with SLD source and shows particularly good performance on small bend-loss,high extinction ratio and high polarization stability.(3) According to the fabrication processing of SMFD-NEIC-PCF,A new theoretical analysis model of fiber birefringence and extinction ratio deterioration induced by diameter variation and longitudinal stochastic variation of silicon capillaries used for fiber preform is established.The transverse and longitudinal diameter error tolerance ranges of capillaries can be calculated on given extinction ratio,which show a good reference on fabrication processing of PM-PCF.Based on this theoretical analysis,the SMFD-NEIC-PCF is fabricated by strict control of fiber drawing technology.(4) A novel closed-loop interferometric FOG based on SMFD-NEIC-PCF is proposed. The effects on output performance of FOG such as polarization non-reciprocity of fiber coil,coupling error of splices,polarization degree of fiber and power variation are investigated.(5) A novel high stability fiber laser with all polarization-maintaining non-splices linear optical resonator realized by directly writting FBGs in a photosensitive polarization- maintaining erbium-doped fiber(PM-EDF) using UV laser is proposed and demonstrated.It shows stable performance both on output power and operating wavelength,which can be applied on high precision resonator FOG or other high sensitivity fiber sensor system.