Study On Key Technologies Of High Power Fiber Bragg Grating Laser

With the rapid development of special fiber, cladding coupling, semiconductor pumping and other technologies, high power fiber laser technology has entered a rapid development period. This paper introduces the principle of fiber grating, the fabrication experiment of fiber grating technology and characteristics analysis, and carries out the research on the fabrication of 1550 nm double cladding fiber grating. The optical fiber is imported photosensitive double-clad fiber with a small amount of Germanium Doped in the core. The diameter of the core is 7 m and the numerical aperture is 0.15. The inner cladding is plum petal-shaped with a diameter of 105 m+5 m, a numerical aperture of 0.32 and a diameter of 130 M. A double clad fiber grating (DCFG) is fabricated by using a phase mask corresponding to the 1550 nm reflection band and by increasing the output energy of the KrF exciter laser pulse. When the output energy of KrF exciter laser is 400 mJ and the frequency is 25 Hz, the reflection spectrum and transmission spectrum of the double clad fiber grating obtained from the experiment indicate that the most important factor affecting the central reflection wavelength and power of the fiber grating is the environment and the stress on the axis of the grating. So the temperature and stress characteristics of Bragg FBG are the basic characteristics of calibrating FBG. The central wavelength of FBG drifts with the change of temperature and stress.