Study On Characteristics Of 1.6μm Er:LuAG Solid State Laser

The demand for the precise measurement of the atmospheric wind field is more and more urgent as a result of the worsening condition of the global climate. In recent years, Coherent Doppler lidar has become hotspot research due to its advantages of high accuracy and high sensitivity. Beacause 1.6μm is in the hunman safety and the atmospheric transmission window, so the 1.6μm solid state laser becomes a new hot spot laser source of the radar. Er:Lu AG is an ideal alternative crystal for Er:YAG, it not only has the good physical performance of Er:YAG, and its main emission wavelength of 1650 nm can avoid the absorption of methane and other gases in the air, which makes Er:Lu AG becomes outstanding in Coherent Doppler radar’s light sources. Therefore, this paper researched on the characteristics of 1.6μm Er:Lu AG solid state laser on both respects of theory and experiment.Theoretically, first,the spectral characteristics of the Er:Lu AG crystal is introduced. Then, the theoretical model of quasi-four-level rate equations has been established for continuous wave and Q-switched operation at room temperature according to the transition mechanism of Er3+ iron generation 1.6μm laser. The effects of the output mirror and conversion factors on the continuous laser and the effect of the dimensionless z parameter on the pulse laser have been analyzedd respectively. Finally, the principle of choose single longitudinal mode has been analyzed, and the influence of the F-P etalon parameters on the transmittance curve has been discussed.Experimentally, first of all, we studied on the output performance of the continuous laser of Er:Lu AG. Based on the experiment, we discussed the crystal doping concentration, cavity length and the output mirror’s effect on the output characteristics of Er:Lu AG continuous laser. And finally a maximum output of 1.38 W was obtained under the pump power of 10.4W, corresponding to the slope efficiency of 18.8%. Fouthermore, we researched on the performance of the Q-switched Er:Lu AG laser. When using the “L” cavity resonator, a maximu single pulse energy of 2.0m J and pulse width of 37.6ns was achieved under the repetition frequency of 100Hz; When using the “8” ring cavity resonator, the maximum pulse energy was 3.51 m J with a pulse width of 90.5ns, correspondting to the repetition frequency of 100 Hz. At last, we studied on the single frequency laser of Er:Lu AG, obtaining the single longitudinal mode of 1650.2nm and 1628.1nm laser output, the maximum output power are 154 m W and 114 m W, respectively.