The basic structure of optical fiber laser is basically the same as other lasers. The fiber laser is mainly composed of pump source, coupler, rare earth element doped fiber and resonator. Pump source consists of one or more of the high power laser diode, big flow hydraulic test pump from the pump by the special pump structure coupled into the fiber as gain medium rare earth doped element, pump wavelength of the photon is absorbed by the doped fiber media, form the population inversion and stimulated radiation wavelengths by the resonator mirror feedback and oscillation laser output.