Research On High Power1064nm Single Frequency Laser

In solid-state lasers’fifty years development history, the laser diode-pumped solid-state laser (Diode-Pumped Solid-State Laser) has become one of the research priorities with the advantages of both semiconductor lasers and solid-state lasers. From late nineteen nineties, DPSSL’s industrialization prospect has become increasingly promising due to the growing market demand. Many solid-state lasers, especially the one single frequency lasers, have been widely used in industrial processing, medical services, printing, military and communications, and high-power1064nm single-frequency laser is the research basis of other single-frequency lasers with different wavelength. The two main research directions of solid-state single-frequency laser study are the selection of single longitudinal mode and the increase in power. However, it is quite difficult to achieve high power laser output and single-frequency laser operation in the same time. In this thesis, a high power1064nm single-frequency laser has been obtained adopting Nd:YVO4crystal, using four-mirror ring cavity, taking Faraday rotator and a half-wave plate as the optical isolator under complete theoretical analysis and experimental research.In the first and second chapter, firstly theoretically analyze and optimally design the1064nm single-frequency lasers and select the structure of the resonator in order to eliminate the effects of spatial hole burning. Then analyze the principles and formula derivation of equivalent thermal lens, and conduct simulation calculation based on the parameters of crystals used in experiments.In the third chapter, select the four-mirrors ring cavity as the cavity structure of single-frequency lasers according to the analysis in previous chapters. Obtain the focal length of the equivalent thermal lens through calculations and experiments based on known parameters. Based on ABCD transfer theory, design the parameters in the ring cavity under the resonator’s stability conditions and calculate the size of the oscillation spot. According to the mode matching principle, design the coupling lens group and get preferable pattern matching. Optimize the effect of astigmatic on the spot by choosing cavity parameters.In the fourth chapter, obtain a high-power1064nm single frequency laser in experiments which adopt parameters achieved by analysis. When the pump power is30W, there is12.22W1064nm single transverse single longitudinal continual laser output. Light-optical conversion efficiency is approximately40.73%, and the line width is less than100MHz. The beam quality in horizontal and vertical directions is about M2=1.1.