Research On Output Efficiency Stimulation And Experiments Of Cr,Tm,Ho:YAG Laser System

Cr,TM,Ho:YAG laser output of 2.1um wavelength light is close to one absorption peak of water molecules,besed on the nature that the output energy can be absorbed by human tissue, it has a very wide range of applications in the field of clinical medicine. In this paper, we mainly study the efficiency of laser coupling system.The coupling efficiency of the laser is an important factor that affects the output power of the laser and the stability of the whole system. In this paper, the simulation and experimental research carried out on the coupling system of the laser is based on the theory of Cr, Tm, HorYAG laser system and the practice on the system.In the beginning of the paper, the characteristics and principles of the working materials is describled. The pumping source and cavity suitable are selected based on the optical properties between different cavities and pump sources and the laser materials. According to the performance requirements of the whole system, the cooling system, power suppling system, the laser system is described in detail.Based on this,the pumping source and suitable cavity are selected.Factors affecting the coupling efficiency of the system theory is discussed. And through simulation experiment, optimization of the laser beam waist width and divergence angle is verified by experiments.Output beam enters the coupling fiber after passing through the single lens coupling system, The radius of beam waist,divergence angle,fiber core radius, numerical aperture and other parameters have a critical effects on the coupling efficiency.The thermal lens effect is obvious when system works at high frequency and high power output. So we simulate the thermal distribution of the crystal under high frequency, and the equivalent thermal focal length is calculated. The laser output is multimode laser beam, by calculating the beam waist diameter and the position of different beam qualities and divergence angles,the focal length is optimized.The experimental results shows that the coupling efficiency of the modified coupling system is obviously improved compared to the original one.the output energy from the fiber end is obviously improved.Higher energy can be obtained when the fiber with 365μm diameter is used.