Research Of The Solid Frequency-doubled Laser Pumped By Laser-Diode

The research of laser Diode(LD) pumped solid-state-laser(DPSL) and its relevant theory and technology is the currently main developing direction in the area of laser. This dissertation has made some theoretical and experimental study closely around the characteristics of DPSL.In the theory part, based on the rate-equation theory of four-level system, the expressions of output power and slope efficiency under the conditions of near-threshold and deeply pumping have been given. The effects of space distribution variables(the position of focusing point, dimension of pumping light and laser light and ellipticity)on the output characteristics were also discussed. As for the quasi-three-level system, the expressions of output power and slope efficiency were firstly conducted, and the effects of the dimension of pumping light and laser light, crystal length, and transmissivity of output mirror were investigated. These discussions provide a theoretical basis to the optimum design of LD endpumped laser.In the experiment part, two CW LD were used to pump the Nd:YAG laser material, and the KTP was used to be the frequency-doubled crystal. 260 mw green light output power was achieved. Output power of different cavity length was measured and accorded with theory. In addition, the Nd:YVO4 laser material was pumped by one CW LD, and its absorb spectrum was measured. Using direct-coupled pump and the optical couple system, we obtained 240 mw and 130 mw output power respectively. The practical miniature DPSL frequency-doubled laser was also manufactured.