Study On High-Power Ytterbium (Yb～(3+))-Doped Double-Clad Fiber Laser

High power fiber laser is a novel laser technology that combined of the LD fiber modules and its pumping techniques, double-clad fiber(DCF) fabricating technology and fiber grating techniques. Fiber laser has a important role of application in many fields. It has come in being a laser industry of several billion USD all over the world, and fiber laser has been called one of the greatest inventions at the beginning of 21st Century. So there should be an important meaning on energetically development work in the field of fiber laser.The basic operation principle and the recent development was summarized generally, the realization of high power fiber laser and its key techniques were analyzed, which including high power fiber pumping modules> DCF and fiber grating technologies, etc.The advancement with the conception of double-clad fiber makes it possible that fiber laser as a type of device with high-power output. In this paper, by using the method of geometrical optics and the theory of fiber optics mode, we analyzed difference characteristics of double-clad fiber andthe effect of all kinds of DCF's inner-cladding structures on1 the absorption efficiency of DCF and its laser. The analyzing model was established, and a novel inner-cladding structure of DCF with higher performance was designed.Integrated by the absorption and emission characteristics of rare-earth-ions in DCF and the LD's pumping principle with its relative references, the-academic model of high power DCF laser with F-P cavity was based, by using methods of numerical analysis, the high power DCF laser was simulation with good results and consistency.Relative to the shortcoming and difficulty of the realization of fiber laser with lenses-coupling and dichroic-coating mirror, a novel all-fiber DCF laser structure was designed, the beam-reducing, high efficiency splicing of fibers with large-core and the double-clad fiber grating as resonant cavity. The measuring and experimental equipment were set up. The high power fiber laser with CW (continuous wave) output more than 10 Watts, the laser beam is near diffraction-limited single mode (TEMOO). This all-fiber-structure high power fiber laser has the markedsense of practicability.The new fiber laser, including photonic crystal fiber (PCF) laser and multi-core double-clad fiber laser, was analyzed. One of novel structure. DCF laser that will be used into high power output was put forward based on the theoretic analysis.Working on laser diode fiber-coupling modules was summed up, They are, setting up the model of far-field distribution of laser array and the far-field characteristics of difference structures; designing the temperature-controlled laser diode fiber modules, that has been used as a laser system with temperature-controlled and fiber-output; realization with high-brightness laser diode fiber-coupling modules; the fiber's application in the field of high power laser.Work on the research of microcavity semiconductor laser was summarized.