激光V型腔参量对输出性能的影响

Influence of V-cavity parameters on laser output performance

在激光腔型设计时,为了使激光具有良好的输出性能,需要找出谐振腔参量对激光输出性能的影响规律。结合V型折叠腔的图解分析法和多元件光学谐振腔的等价腔分析法,将折叠腔近似等价后,对等价的共轴球面空腔的稳定性和输出光束质量进行理论求解分析,找到了V型折叠腔参量和激光输出性能的内在联系。通过计算给定的条件可知,当折叠角θ=0.15π时,总腔长L的理想取值范围为(70,80)mm,最佳取值为75 mm,端面镜曲率半径R1、R2的允许变化范围为(60,75)mm,折叠镜曲率半径R3的最小取值为45 mm,随着左(右)侧子腔g-参数积增大,右(左)侧端面镜上的基模光斑半径和远场发散角增大。上述等价腔分析法和结论对激光腔型优化设计提供了重要的理论依据。

In order to make the laser with V-resonator have good output performance, it is necessary to find the influence rules of cavity parameters on the laser output performance in laser cavity design.Combining the graphic analysis method of V-type folded cavity and the equivalent cavity analysis method of multicomponent optical resonator, the stability of the equivalent coaxial spherical cavity and the output laser beam quality were theoretically solved and analyzed after equivalent approximation of the folded cavity. The internal relationship between the V-type folded cavity parameters and the laser output performance were found. By calculating the given conditions, some results were known. The ideal value range of total cavity length L is 70-80 mm with the optimal value 75 mm when the folding angle θ is equal to 0.15π. The allowable variation range of curvature radius of end mirrors R1 and R2is 60-80 mm. And the curvature radius of of folding mirror R3 has a minimum value of 45 mm. The laser spot radius and the farfield divergence angle of fundamental mode on the right(left) end mirror will become larger with the increase of g-parameters of left(right) subcavity. The above-mentioned equivalent cavity analysis method and the achieved results can provide an important reference theoretically for the cavity optimization design.