Theorical And Experimental Study Of Double-Clad Fiber Laser

The fiber laser develop very fast resent years for its advantage of compact structure, good beam quality, high reliability, efficiency and long life, and so on. And As the emergence of double-clad fiber and double-clad pumping technology, high power fiber laser's development become not very difficult. The fiber laser can be used in communication system, industry, military and medicine more and more widely.In the dissertation, theoretical and experimental investigation of double-clad fiber laser are presented. The main research subject include:In the first chapter, the fiber laser's history of development, the research status quo, the virtue, and the application is summed up. It present a realization of fiber laser as a whole, This can be help to our theoretical and experimental research.In the second chapter, the basic theory and the structure of double-clad fiber laser is researched. According as the constitute of double-clad fiber laser, we discuss the structure and characteristic of double-clad fiber, the cavity and the coupling technology.In the third chapter, we do the theoretical research of LD pumped Yb³⁺-doped double-clad fiber laser, which is the currently mature high power fiber laser. According to the characteristic of Yb³⁺-doped double-clad fiber and fiber laser's rate equation, we do the theoretical research of laser output characteristic. Finally we detailedly analyze the F-P cavity for our experiment.In the fourth chapter, the experimental research of LD pumped Yb³⁺-doped double-clad fiber laser put in practice. In the experiment, we optimize the pump coupling and cavity system, using F-P cavity, adjust the light path accurately. When the laser was pumped with LD forward, and the LD's power is 15.5W, we obtain 4.26W, 1081nm near single mode laser; We also study different fiber length and different LD temperature' s influence to fiber laser's output characteristic. The backforward LD pump fiber laser is also researched. The experimental results are explained and mostly accord with theory.In the last chapter, we sum up the whole dissertation and present some idea and suggestions.