基于柱面变形反射镜的低阶像差补偿技术研究

发布时间：2018-10-22 12:04

【摘要】：板条固体激光器在获得高平均功率激光输出方面具有独特优势,正越来越多地受到人们的关注。然而由于固体增益介质中存在的热透镜效应、泵浦非均匀性和热致双折射效应等不良因素,导致输出光束中存在着较大PV值的低阶像差,限制了光束质量的进一步提高,因此板条固体激光器的低阶像差补偿技术研究有着重要的实际意义与广阔的应用前景。本文基于反射式柱面整形系统对板条固体激光器的低阶像差补偿问题进行了研究。论文设计完成了一套用于补偿低阶像差的反射式柱面光束整形系统。建立了该系统的矩阵光学模型,分析了其对低阶像差的补偿原理,给出了离焦、像散系数与补偿控制量的解析算法,并通过实验研究验证了反射式柱面光束整形系统中利用解析算法进行低阶像差补偿的可行性。其次研究了柔性铰链结构的柱面变形反射镜的结构和工作性能。针对反射式柱面光束整形系统在低阶像差补偿中存在的不足,进一步提出了在整形系统中采用柱面变形镜进行低阶像差补偿的方法。通过结构力学分析确定了柱面变形镜的力学加载方式;提出了柔性铰链结构的柱面变形镜结构设计,并通过有限元仿真优化了变形镜的结构参数;对加工制作的样镜进行了性能测试与标定,测试结果表明,采用柔性铰链的柱面变形镜具有较大行程和较小的拟合残差,变形量PV值达到15μm,残差PV值小于0.6μm。构建了基于柱面变形镜的低阶像差闭环补偿实验系统,开展了对不同低阶像差的补偿实验。实验结果表明本文设计的柱面变形镜对低阶像差具有较好的补偿效果,补偿后的残差中低阶成分PV值小于0.05μm。光束传输因子提高到50%以上,可满足固体激光低阶像差的校正需求。
[Abstract]:Slab solid-state lasers have unique advantages in obtaining high average power laser output, and are attracting more and more attention. However, due to the thermal lens effect, pump inhomogeneity and thermally induced birefringence in the solid gain medium, the low order aberration of PV value exists in the output beam, which limits the further improvement of the beam quality. Therefore, the study of low order aberration compensation technology of slab solid state laser has important practical significance and broad application prospect. In this paper, the low order aberration compensation of slab solid state laser is studied based on the reflective cylindrical shaping system. A reflective cylindrical beam shaping system for compensating low-order aberration is designed and completed in this paper. The matrix optical model of the system is established, and the compensation principle of low order aberration is analyzed. The analytical algorithm of defocusing, astigmatic coefficient and compensation control is given. The feasibility of low order aberration compensation in reflective cylindrical beam shaping system is verified by experiments. Secondly, the structure and performance of cylindrical deformable mirror with flexure hinge structure are studied. Aiming at the deficiency of the reflective cylindrical beam shaping system in the low order aberration compensation, a method of low order aberration compensation using cylindrical deformable mirror in the shaping system is put forward. The mechanical loading mode of cylindrical deformable mirror is determined by structural mechanics analysis, and the structural design of cylindrical deformable mirror of flexure hinge structure is proposed, and the structural parameters of deformable mirror are optimized by finite element simulation. The test results show that the cylindrical deformable mirror with flexure hinge has larger stroke and smaller fitting residuals. The PV value of deformation is 15 渭 m, and the residual PV value is less than 0.6 渭 m. The closed-loop compensation system of low order aberration based on cylindrical deformable mirror is constructed and the compensation experiments of different low order aberrations are carried out. The experimental results show that the cylindrical deformable mirror designed in this paper has a good compensation effect on the low order aberration, and the PV value of the low order component of the compensated residual is less than 0. 05 渭 m. The beam propagation factor is increased to more than 50%, which can meet the need of low order aberration correction of solid state laser.
【学位授予单位】：国防科学技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN248.1

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