Research On The Output Characteristics Of Self-Q-switched Pulses Based On Tm:YAP Solid-state Lasers

2 μm laser is eye–safe and in the atmospheric transmission window,and its application value causes people attention.Pulse laser has the advantages of narrow pulse width,high peak power,far transmission distance.The Self-Q-Switching is one of the effective means of generating pulsed laser.The Self-Q-Switching laser has low cost,compact structure,and small cavity loss etc,and it has potential applications in the scientific research,medical and other fields.In this thesis,the 792 nm laser diode is used as the pumping source of Tm:YAP laser,and a 5at.% Tm:YAP laser crystal is used as the gain medium.By adjusting the cavity length to realize the cavity mode matching and the angle of the cavity mirror to change the cavity losses,the Self-Q-Switching laserat 1.94 μm is obtained.In theory,under the condition of plane wave approximation,the rate equation theory mode of self-Q-Switching Tm: YAP laser is built.Through the numerical simulation,the parameters of the resonator cavity are optimized,and the best crystal length,doping concentration of Tm ions,and transmittance of the output coupling mirror are given.The output performances of the self-Q-switching Tm:YAP laser are analyzed theoretically,which provides the theoretical basis for the following experiment.In experiment,the Tm:YAP laser with the plat-concave cavity structure is built.The curvature radius of the output coupling mirror is 300 mm.The cavity length of the resonator is adjusted to obtain the maximum output power of continuous wave laser.The influences of the transmittance of output coupler and the core diameter of output fiber are analyzed.Carefully adjusting the length of the cavity and the angle of cavity mirrors,under consider the thermal focal length,the stable self-Q-Switching pulse output can be achievedwhen the cavity length is 310 mm.Furthermore,the output performance are reasonably analyzed.