Study On Photosensitive Optical Fiber And Fiber Bragg Grating Devices

The development of Fiber Bragg Grating (FBG) is a great breakthrough follow the Erbi?m Doped Fiber Amplifier (EDFA) in optical area. FBG can be used in fiber laser, dispersion compensator, wavelength convertor, add/drop multiplexer, EDFA equalizer et al, these devices are all indispensible in all optical networks. The Bragg wavelength of FBG has the well linearity with the temperature and pressure, it can be used as the sensor cell of many phisical parameters. This kind of optical fiber sensor has shown vastitude application foreground and huge market potential in bridge, tunnel, construction, aviation and space areas.This thesis studies from the base material of fiber grating-photosensitive fiber, then research on the fiber grating and the series of fiber devices. The photosensitive fiber is the base material for write fiber grating, would influence the fiber grating's performance greatly. Form the study of photosensitive fiber and the fiber's photosensitivity, the best way to get the high quality fiber grating would be got. Then deep research on the application of fiber grating in the optical communication and sensing areas, especially on the chromatic dispersion compensation device. Study the fiber design, fiber grating fabrication, encapsulation of the device, performance measurement of the device. Based on these researches, design and optimize the photosensitive fiber, develop the low PMD cladding mode depressed photosensitive fiber for the fiber bragg grating device's application. Then the fiber fabrication, grating written, grating encapsulation, performance measurement of chirp fiber bragg grating chromatic dispersion compensation device have been realized.This thesis involves material, optical, communication, sensing areas, the main research production are:(1) Expound the theory of fiber's photosensitivity, compare the many kinds of method to increase the fiber's photosensitivity, design and fabricate the special photosensitive fiber for fiber grating writing. Developed two kinds of photosensitive optical fiber: the high Ge doped photosensitive fiber and Ge/B codoped photosensitive fiber, with compare the two kinds photosensitive optical fiber's photosensitivity, find the advanced photosensitivity design of optical fiber. Adopt the ITU-T standard test methods to measure, analyze, and study the different doping photosensitive fiber's dynamic fatigue, prooftest strength, tensile strength;(2) Based on the requirement in the system application, optimize two key characters of the FBG: polarization mode dispersion and cladding mode couplling loss. Bring forward the low PMD CMS photosensitive fiber, research the fiber design, performance measurement, and grating write condition. FBG written by this new fiber shown the high cladding mode depression and low PMD value, these characters indicate that this new fiber has the well birefringence and cladding mode depression abilities;(3) Deep research on the fiber grating chromatic dispersion compensator's every aspect, such as the FBG fabrication, encapsulation, measurement. Theoretical and experimental analyze of the chirp FBG high temperature encapsulation method for optimize the temperature stability;(4) System research of several important characters of the FBG dispersion compensator device. Combine the experiment data to deep theoretical research on the group delay, group delay ripple, and phase ripple. Base on the practice application, analyze the PMD, PDL, insertion loss of the FBG dispersion compensator and the influence of system performance by these characters. Through these measurement and analyse, bring forward the method to reduce the chirp FBG device's group delay ripple, phase ripple and optimize it's PMD and PDL.