| 2m band laser is eye safety and in weak absorption zone of atmosphere, canbe used to bring the laser radar, wind field measurement, medical treatment etc. Inparticular,2m band laser is high efficiency pumping source for infrared opticalparametric oscillator (OPO). So, people urgently demand2m band laser whichhas good properties of compact, high efficiency, high peak power etc.This paper’s main objective is to develop a good performance Ho:YAG laserwith Q switching,2.09m wavelength output, it is pumped by Tm:YLF solid laser.In1000Hz modulation frequency, through the laser amplification technology, wemake Ho:YAG laser produce pulse energy output as much as30mJ, as a highefficiency pumping source for infrared ZGP OPO.In theory, we analyzed relaxation oscillation phenomena of Tm:YLF laser andformulated the control measures; we discussed the effect of the focal length of theheat on the stability of the resonator and the effect of a quarter wave plate oncompensation mechanism of the thermal induced depolarization; The analysis anddesign of the mode matching system between lasers was established, and wesummarized the continuous and pulse laser’s performance parameters and theexperimental measurement methods.In experiment, we restrained the relaxation oscillation of Tm:YLF laser andobtained the smooth continuous power output. The highest power50.2W has beenreached with slope efficiency46.43%. The output wavelength of Tm:YLF laser was1908.03nm, just in absorption peak of Ho: YAG crystal. We optimized the variousparameters of Ho:YAG laser. In the curvature5000mm of output lens, thetransmissivity50%, we got the biggest energy15mJ of single longitudinal modeoutput, and the average extraction efficiency was97.17%. The beam quality factorM2was1.213at continuous output power of12W.Using Master Oscillator Power-Amplifier (MOPA) structure, we got amplifiedpulse output31.2mJ with pump power55.2W, pulse width35ns, average energyextraction efficiency36.13%, pulse wave range0.4mJ, and output unstability lessthan1%. Degree of vertical polarization was93.7%in the output power30W of Ho:YAG amplifier, and finally2092nm wavelength output of single longitudinal modewas formed. |
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