LD End-Pumped Double Rod Tandem Tm:LuAG Laser

With the continuous development of laser technology,the LD pumped Tm³⁺laser（DPSSL）that produces a 2μm laser band is widely used due to its advantages such as safety and portability.In this paper,theoretical analysis and experimentation were carried out to study the LD end-pumped Tm:LuAG lasers with two crystal rods connected in series.The main research contents are as follows:Theoretically,based on the LD end-pumped Tm:LuAG laser rate equation model,the effects of upconversion and reabsorption effects on the laser output are analyzed.Based on LD end-pumped Tm:LuAG Q-switched laser rate equation model,the effect of laser operating frequency on laser output is analyzed.Based on the heat conduction theory,the temperature field distribution in different bonded Tm:LuAG crystals was analyzed,and the thermal focal length of the crystals was simulated when the single rod Tm:LuAG and double rods series with Tm:LuAG.Designed single rod Tm:LuAG laser resonator,double rod series Tm:LuAG laser thermal self-compensating resonator,double rod series Tm:LuAG Q-switch laser thermal self-compensating resonator.Taking into account the thermal focal length of the Tm:LuAG dielectric,the resonant cavity stabilization range is simulated,which will pave the way for follow-up experiments.In terms of experiments,the thermal focal length and absorptivity of the Tm:LuAG crystal were measured.Based on this,an LD pumping Tm:LuAG laser experiment was carried out.Firstly,the LD end-pumped single-ended bonded Tm:LuAG laser experimental study was carried out,pumping 28.8W,outputting4.75W,slope efficiency 19.08%,optical to optical conversion efficiency22.7%.Secondly,the experiment of LD end-pumped double-bonded Tm:LuAG laser was carried out,pumping 34.1W,outputting 5.75W,slope efficiency 18.73%,optical to optical conversion efficiency 21.86%.Then,developed LD end-pumped double rod series Tm:LuAG laser experimental study,pumping 40.1W,output 6.03W,slope efficiency 15.89%,optical to optical conversion efficiency 13.0%.What’s more,comparing the laser output at the same pumping power of single-rod and double-rod Tm:LuAG lasers,the results show that the double-rod Tm:LuAG thermal self-compensation system can increase the output power of Tm:LuAG lasers.Finally,the LD end-pumped double rod series Tm:LuAG Q-switched laser experimental study was conducted.The results showed that the output of the laser was the best when Q100Hz was adjusted.At this time,the single pulse energy was 5.25mJ and the peak power was 9717W.