Study On High Power All-solid-state CW Green Laser Of LD Single-End-Pumped Nd: YVO₄/LBO

In the first chapter of this paper, diode-end-pumped all-solid-state laser's main features and advantages, its field of application as well as the present development as home and abroad is introduced.In the second chapter, the operating principle of solid-state laser is analyzed. Based on the model of four-level system and with the space-related rate equations, the space distribution of laser beam and pump beam, the threshold pump power, the output power, the slope efficiency, the input-output characteristic and the effect of space variables on the output character are studied. Also, the introcavity second harmonic generation (SHG) theory is discussed.In the third chapter, by the analysis of the thermal lens effect of laser crystal, single-end-pumped laser crystal is analyzed and a thermal model suited for particular operating circumstance is founded. By the use of equation of heat conduction and with the boundary conditions, the half analytic solution of thermal field in the laser crystal is obtained through half-analytic thermal analysis, and a practical example is calculated together with analysis of the effect of some parameters on the distribution of thermal field.In the fourth chapter, the coupling system between the fiber-coupled-output high power semiconductor laser acting as the pumping source and laser crystal is studied. By the method of matrix optics, the waist width and imaging distance of Gauss beam through the self-focusing micro lens system and the double plan convex lens coupling system are deduced.In the fifth chapter, the optical characteristics of Nd:YVO4 and LBO are studied. Grounding on the purpose of industrialization of laser, based on the thought of astigmatism compensation and thermal stability of the cavity, we employed high power LD to pump Nd:YVO4 crystal and used the introcavity frequency doubling with type 1 noncritical phase-match LBO crystal, which has high damage threshold. The cavity parameters are optimized by the use of ABCD theory and the resonatorstructure CAD software. The external form of laser, the cavity structure and the mechanical components are designed by mechanism drawing software AutoCAD and UG. There is a water-cooled CW 532nm green laser with the maximum output power of 9.9 W, along with a semiconductor-cooled CW 532nm green laser with the maximum output power of 6.4 W are developed.The sixth chapter is the summarization and prospect of the paper.