Research On Q-switched Single Longitudinal Mode All-solid-state Laser

With the development of semiconductor laser and its rapid development, All-solid-state laser(Laser Diode Pumped Solid-state Laser or DPSSL), refers to which using the laser diode(LD) as pump source has become a hotspot in the field of solid-state laser technology, now many scholars are actively studying this field, it is an important development direction of all-solid-state laser. However, due to the spatial hole burning effect of the active medium, the laser generally working in multi-mode oscillation, which has multiple longitudinal mode oscillating at the same time, the more oscillation mode with the stronger laser. Will be mutual coupling between multiple longitudinal mode which make the bigger output noise. In order to reduce the noise, we can keep the laser running at single longitudinal mode state, meanwhile we can get a narrow pulse width of laser output. At present the single longitudinal mode laser has became an important research content in the field of all- solid-state laser, it is widely used in the laser measurement, laser communication, optical frequency standard and high resolution spectroscopy etc. To this end, this paper carried out the following work:The single longitudinal mode pulse all-solid-state laser is designed and assembled at 1064 nm, a better beam quality of the pulse laser is obtained by the reasonable designing of cavity, and then the Fabry-Perot etalon is used to choose mode and restrain the oscillation of adjacent lines, the stable single-frequency pulse laser output at 1064 nm is obtained. In order to facilitate observation and adjustment, we use the KTP change the 1064 nm to 532 nm which we can see with the naked eye in the experiment, the character of laser longitudinal mode through the isoclinic interference fringe obtained is detected by the etalon, then we can study characteristics of single longitudinal mode. Finally, we obtain 310 mW single longitudinal mode pulse output power at 1064 nm when the pump power is 4.8W, the pulse width is 8 ns, the peak pulse repetition frequency is 29 kHz, the light to light conversion efficiency is 6.46%.