Research On Resonant Pumped Gain Switch Er:YAG Laser

The high repetition frequency 1.6μm band laser is located in the greenhouse gas absorption band,with high atmospheric transmittance and no damage to human eyes.It has many applications in military,medical,and life fields.In this paper,the 1532nm laser resonantly pumped gain-switched Er:YAG laser has been studied in detail from both theoretical and experimental aspects.In theoretical research,the accumulation equation of laser upper-level particles with gain switch pumped Er:YAG with energy up-conversion and cross-relaxation is established,and the Er³⁺doping concentration,energy density and the effect of the pump pulse on the laser upper energy are simulated and studied.The influence of the accumulation of the number of particles in the first stage provides a theoretical basis for the selection of Er³⁺doping concentration,pump energy density and pump pulse width.In the experimental research,first designed a resonant pump gain switch Er:YAG solid-state laser experimental platform,using a high repetition frequency 1064nm fiber laser as the signal source,using periodic polarization PPLN optical parametric technology to generate high repetition frequency 1532nm pump light.Then use high repetition frequency 1532nm pump optical gain switch to pump Er:YAG crystal to obtain high repetition frequency 1645nm laser output.Then completed the relevant experiments of the resonant pump gain switch Er:YAG solid-state laser,and studied the influence of the cavity length,the repetition frequency of the pump source and the transmittance of the Er:YAG laser output mirror on the 1645nm output power.The relationship between the repetition frequency of the gain-switched pump source and the repetition frequency of the laser output is studied.Finally,a 1645nm laser output with a repetition frequency of 100k Hz,a pulse width of 21.67ns,and a power of 0.87W was obtained.The corresponding peak power reaches 0.40k W.When the repetition frequency is 40k Hz,our peak power reaches a maximum of 1.42k W,and the pulse width reaches 11.2ns.