Theoretical And Experimental Study Of Pulse Pumped Ytterbium-doped Double-clad Fiber Laser

Yb-doped double-clad fiber (YDCF) lasers have the advantages of compact structure, broad output wavelengths, simple cooling, high power and high efficiency. During the recent years, YDCF lasers have been enhanced and they are widely used in optical communication, industry process, medical treatment and so all.Pulse pumped YDCF lasers are studied both theoretically and experimentally in this dissertation. The main point can be concluded as follows:1, The principal, application and recent development of YDCF lasers have been introduced2, The basic theory of YDCF lasers has been summarized. Starting from the solution of the rate equations of the YDCF lasers, the solution of the YDCF laser is educed. The impact factors of output of the YDCF laser are analyzed particularly.3,The output characteristics of pulse pumped YDCF master-oscillator power amplifier (MOPA) have been numerical simulated. The pumping pulse's width and the signal seed pulses entre time have been optimalized. At the same time,the output characteristics of the pulse pumped MOPA are compared with the CW situation.4,The pulse pumped YDCF all fiber laser system have been studied in experiment. (1) The Q-switched pulse signal is achieved by using the single mode fiber's SBS effect. Pumped by a 915nm laser diode (LD) of 2.51W, the passive Q-switched pulse is obtained. The pulse sequence repetition rates is 4.6kHz, the average power is 315mW,the pulse width is 500ns,the single pulse energy is 68.4μJ,the peak power is 136W.(2) The experiment research of pulse pumped YDCF MOPA system. The seek pulse signal through the pulse pumped MOPA amplifier stage in different pump pulse width and repetition rates. The pulse pumped amplifier results have been analyzed and compared with the theoretical results.