卡式系统装调对高功率激光光束远场聚焦性能影响研究

Study on the Influence of Alignment of Cassegrain System on the Propagation Properties and Beam Control of High-Power Lasers

以广义惠更斯-菲涅尔衍射理论为基础,采用Zernike多项式描述像差光束畸变波前相位,研究超高斯光束因卡式系统加工和装调导致波像差劣化后,通过传输在远场聚焦性能。分析主次镜系统波像差下降到1/13λ左右时,对应像散和慧差对聚焦位置处光强分布和光斑桶中功率PIB影响。结果表明:相对理想系统,像差会导致聚焦位置处光束展宽,80%处桶中功率PIB下降明显,但对应95%能量范围光斑直径在设计值允许范围内,仍然满足总体使用要求。

By using Zernike polynomials to describe the wavefrontdistortion of beams,the focusing performance of super Gaussian beams in far field are studied based on the generalized Huygens-Fresnel diffraction integral.The influence of astigmatism and coma on the intensity distribution at focusing position and the power in the bucket(PIB)are analyzed when the aberration of Ca system decreased toλ/13.The results show that the aberration will lead to the beam broadening at the focusing position,and the PIB in 80%decreases obviously,but the spot diameter in 95%of the energy range is still within the design value range,which meets the overall design requirement.