Experimental Studies On Laser Diode Pumped Tm: YLF Laser

2-micron laser has been attracting many researchers for its unique characters. It's provided with broad applications in laser remote sensing, laser target detecting, spectra analysis, medical diagnoses and therapy, scientific apparatus, material disposing, optical signal disposing, data disposing, atmospheric environment monitoring and so on.Theoretically, the dynamics of Tm:YLF laser is introduced at first. The rate- equation of Tm, Ho quasi-three-level system under room temperature is put forward and simplified. At the same time, the upconversion effect and ground-state depletion of crystal is analyzed elaborately. For the continuous laser, the rate-equation has the analytic result without upconversion, but when considering this effect, the equation has not the analytic root. We have to gain the root by numerical method. The output of continuous operational laser depends on many factors, such as temperature, concentration of ions, length of crystal, coupling of output, the loss of cavity, and the work calculated respectively the effects of them, in order to optimize the laser. Experimentally, this paper introduces the designment of gain medium, pump source and oscillator. Analyze the characters of different hosts. The effects of the dopant concentration of Tm ions and crystal size are discussed. Considering the high-power diode-end-pumped Tm:YLF laser, the effect of the thermal lensing on the output beam quality is un-negligible. Based on the analyses on the effect of the thermal lensing, continuous-pump-oscillator is designed. We achieve 20W, continuous, 1.9-micron laser by using Tm:YLF crystal with diode-end-pumped.Make use of this output laser to pump Ho:YAG crystal, we obtain 2.09-micron laser. At the end of this paper, theoretical and experimental achievement are summarized in this paper, and suggestion to some problems in further study is offered.