束转动90°环形非稳腔抗系统失调性能研究

Anti-maladjustment stability of unstable ring resonator with 90° beam rotation

提出了将束转动90°环形非稳腔(UR90)应用于片状陶瓷激光器的设计,将光束绕光轴旋转对波前进行平均化的思想用于改善固体激光谐振腔失调、增益不均匀、泵浦不均匀等问题。针对该设计模型,采用快速傅里叶变换方法,从镜面倾斜角度出发,计算了不均匀失调因素对输出光束光强、相位分布的影响。与常规环形非稳腔计算结果相比,UR90固体激光腔对系统失调灵敏度要求低,可改善光束质量,有效补偿系统不均匀性。同时,计算了不同放大率参数UR90腔的抗失调性能,发现在小放大率的情况下更能体现和发挥其抗失调性。得到的结论对于UR90腔应用于固体激光器起到理论指导作用。

A design of unstable ring resonator with 90° beam rotation （UR90） applied in sheet ceramic solid-state lasers was presented. The theory that wavefront can be reshaped through beam rotation around the optic axis was used in solid-state lasers to improve the imbalance of solid laser resonator, inhomogeneous gain, uneven pump and so on. Based on the design model, using the fast Fourier transform method, the effect of mirror tilt imbalance on intensity and phase distribution of output beam was simulated. Compared with the results of conventional unstable ring resonator, the sensitivity of UR90 imbalance is lower, beam quality can be improved, inhomogeneity is compensated effectly. The capability of UR90 to reduce tilt aberrations is compared with different magnification parameters, the process of anti-misadjustrnent is more notable when the magnification is less. The conclusion is the theory basis of the UR90 applied to solid-state lasers.