The effect of temperature on the dynamics of a laser-induced cavitation bubble is studied experimentally. The growth and collapse of the cavitation bubble are measured by two sensitive fiber-optic sensors based on optical beam deflection (OBD). Cavitation bubble tests are performed in water at different temperatures, and the temperature ranges from freezing point (0 °C) to near boiling point. The results indicate that both the maximum bubble radius and bubble lifetime are increased with the increase of temperature. During the stage of bubble rapidly collapsing in the vicinity of a solid surface, besides laser ablation effect, both the first and second liquid-jet-induced impulses are also observed. They are both increased with liquid temperature increasing, and then reach a peak, followed by a decrease. The peak appears at the temperature which is approximately the average of freezing and boiling points. The mechanism of liquid temperature influence on cavitation erosion is also discussed.

以三级像差理论为基础，对反射式无光焦度系统的像差进行了分析。得出的结论为：在主、次镜均 为抛物面的前提下，反射式无光焦度系统可以同时消除四种像差。以此结论为基础，综合离轴反射系统的优点，得出了一 套离轴反射式无光焦度系统。以光束口径为φ100mm、缩束倍率β=5、主镜离轴量h=150mm的离轴反射式无 光焦度系统为例，根据系统的像差结果可以看出，三级像差理论的分析结果是正确的。

介绍了利用干涉仪检测调整非球面物镜光路的方法。调整分粗调和精调两个阶段。在粗调阶段，以激光的光轴作 为检测光路的基准光轴，建立起共轴光路检测系统；在精调阶段，以WYGO干涉仪内部倾斜系数作为调整依据，进行物镜的精调。用干 涉仪测得的物镜的面形质量为：波前PV值优于λ/8，RMS值达到λ/100 (λ=0.6328m)，检测结果满足波 前检测镜头的要求。这表明此种光路调整方法能够反映物镜真实的面形精度，并且能用于高精度的物镜检测。