The Study Of The LBO And BIBO Crystal Intracavity-frenuency-doubled Red Laser

Laser diode pumped all-solid-state laser has become an important developing direction in the field of solid-state laser technology. In comparison with the traditional flash-lamp pumped laser, it has many advantages such as high efficiency, high beam quality, good steadiness, compactness, long lifetime and so on. Presently, the laser diode pumped all-solid-state laser has been used widely in the fields of the material processing, medical, treatment military, information, fundamental research and so on.In this dissertation, the research progress and application foreground of LD pumped all-solid-state laser are earnestly analysed. Based on this analysis, the theoretical and experimental researches on all-solid-state 671nm red laser of between the several laser crystals and the several NLO crystals combined systems, are presented. The main achievements are as follows:1,The optical and physical characteristic of Nd:YVO₄,Nd: GdVO₄ is introduced. Then based on the velocity equation of four level system, we analysed the laser thethreshold, output power, slope efficiency, mode matching and so on.2,The nolinear optical frequency conversion theory and the optical or physical characteristic of LBO,KTP are introduced. Based on the refractive index equation of nolinear optical cystal, the phase-matching characteristics of the frequency-doubling and sum-frequency mixing is numerically calculated and theoretically analyzed in the biaxial crystals KTP, LBO and BIBO. The nonlinear optical coefficients tensor of the sum-frequency generation is modified in the optical coordinates system. The phase-matching curve and spatial distribution of the effective nonlinear coefficient, walk-off angle and acceptance angle are performed. Compared to one another, their optimal phase-matching orientation and the corresponding effective nonlinear coefficient are given. The result of calculations is very important for the experimental research on frequency doubling 671nm laser and sum-frequency mixing 447nm laser.3,The optimization resonant parameters were obtained by analyzing the thermal focal lens of the Nd:YVO₄ and Nd:GdVO₄ laser crystals and using the standard ABCD ray propagation matrix and optimun mode matching. By systematically theoretical analysis and experimental research, stable continuous-wave output 671nm red laser had obtained in the four systems of the Nd:YVO₄/LBO, Nd:YVO₄/BIBO, Nd:GdVO₄/LBO and Nd:GdVO₄/BIBO. The corresponding maximal output powers are 67mW, 54mW, 57mW and 38mW, respectively. Compared to one another, the system of Nd:YVO₄/LBO is outstanding. And their lower optical-optical conversion efficiency is analysed.