Theoretical Research And Experiment Of Dynamic Characteristics In Co-cavity Pumping Thin Disc Laser

The thermal effect of solid-state lasers has severely restricted the development of lasers in the direction of high brightness.The birth of disc lasers provides an effective solution for the thermal management of solid-state lasers.Yb:YAG has the advantages of long upper energy level life,small quantum loss,high doping concentration,and spectral line width.It is very suitable for use as a gain medium for disc lasers.However,its quasi-three-level structure makes it affected seriously by temperature.The combination of the fluorescence refrigeration effect and Yb:YAG crystal adding to the disc laser provides a new method to solve the thermal effect of the laser.Since the fluorescence refrigeration requires laser with wavelength of 1030 nm for zero-phonon line pumping,which is hard to be absorbed by Yb:YAG,it is necessary to use co-cavity pumping structure to increase the pump power density.However,it was discovered in experiments that chaos and spikes would be generated in co-cavity pumped laser.This paper establishes complete disk laser co-cavity pumping rate equations and dynamic models in order to find the impact of absorbers with different upper energy levels and 1048 nm laser stimulated radiation on dynamic output characteristics of co-cavity pump lasers.And then explore the influence of other cavity parameters on the laser.The experimental results verify the theoretical results studied.This article mainly has the following parts:a)Established a modulation model with absorber,analyzed the influence of different upper-level lifetime absorbers on the output characteristics of the laser,and studied the correlation between other cavity parameters and the upper-level lifetime.b)A Yb-Yb co-cavity pump model was established,and the influence of 1048 nm stimulated radiation on the laser output characteristics was analyzed.The effects of other cavity parameters on the laser output characteristics are also studied.c)A V-shaped disc cavity was built,and the 1048 nm stimulated radiation produced by the disc 2 was compared with the unstimulated radiation,and the influence of the 1048 nm stimulated radiation on the dynamic characteristics was verified.In view of the spot area ratio,the dynamic output characteristics of the co-cavity pump are optimized to gradually suppress chaotic pulses.Finally,the disc acousto-optic ring cavity is constructed to reduce the impact of multi-mode competition in common cavity pumping.