Study Of Laser Diode End-Pumped 2 μm Slab Laser

The 2μm band laser corresponds to the absorption spectrums of H₂O molecules,CO₂molecules,and gaseous pollutants such as CO,and SO₂and this band is safe for human eyes.Therefore,it has important applications in the fields of atmospheric monitoring,optical communication,laser medical treatment,military defense,and other fields.In order to meet the development needs of various fields,the research on the high performance 2μm solid-state laser is very important.Therefore,this article focuses on the performance of the high power Tm:YLF slab laser.So use it as a pump source,to study the single-frequency Ho:YAG amplifier with 2μm high repetition rate,high energy and high beam quality.The research contents of the paper are as follows:Firstly,the development of the 2μm solid-state laser is described.The laser characteristics of the Tm:YLF crystal are introduced,including the energy level transition and spectral characteristics of Tm³⁺.Then based on the energy level structure of Tm³⁺,a continuous quasi-three-level rate equation model is established.The factors affecting the output performance of Tm:YLF slab laser are studied.Subsequently,the thermal effect of slab Tm:YLF crystal is analyzed.Secondly,a high-power solid-state laser experiment was carried out using Tm:YLF slab crystal.The comparison experiment of crystal doping concentration,crystal axial comparison experiment,and double-end pumped Tm:YLF slab laser are carried out in turn.Experiments show that under the same experimental conditions,the performance of the a-cut Tm:YLF slab laser with a size of 12 mm×1.5 mm×20 mm and a doping concentration of 3 at.%is relatively better than 2 at.%and 2.5 at.%Tm:YLF lasers;For the a-cut Tm:YLF slab crystal with doping concentration of 2 at.%,the output laser performance of c-axis in the horizontal direction is better than the c-axis in the vertical direction;Then,the Tm:YLF slab crystal with doping concentration of 2.5 at.%is used to conduct a double-end pumped laser experiment,which improves the output power of the Tm:YLF slab laser and alleviates the thermal effect of the laser.Finally,the amplification principle of Ho:YAG laser amplifier is described.The output conditions of the Ho:YAG amplifier are theoretically simulated.The laser amplifier structure of Ho:YAG pumped by Tm:YLF slab laser is designed.In order to alleviate the thermal effect,a model of step-doped Ho:YAG ceramic lasers was established.Lastly,the temperature distribution and optimal pumping position of this step-doped Ho:YAG ceramic laser were simulated.