Takingrefraction-reflectionopticalsystemsasatypicalexampleandusingtheASAPopticalanalysis software,thethree-dimensionalsimulationmodelisbuiltup,andthethermalradiationoftheimportant componentsinthesystemisanalyzedquantitatively.Accordingtotheresultsofsimulationanalysis, optimizingandimprovingmethodsareproposed.Especially,themechanicalconfigurationsnearthe imageplaneand theviewfieldareoptimized.Finally,theconceptoftheeffectiveemissivityis introduced,andthesystemperformanceisevaluated.Theresultsindicatethattheeffectiveemissivityof theinfraredopticalsystemafteroptimizationandthestrayradiationperformancearegreatlyimproved.

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一阶空间啁啾高斯脉冲光束的聚焦特性研究 曾曙光 刘 雁 三峡大学理学院, 湖北 宜昌 443002 摘要 空间啁啾效应是超短脉冲中的一种常见的时空耦合效应。对一阶空间啁啾高斯脉冲光束的聚焦特性进行了 较为系统的研究， 推导出了经透镜聚焦后光束的解析表达式。在不考虑透镜色差的理想情况下， 解析推导出了聚焦 后的脉宽、 束宽以及振幅耦合系数的解析表达式。数值模拟了聚焦前后的光强分布， 分析了考虑透镜色差时光束的 脉宽、 束宽以及振幅耦合系数随透镜后传输距离的变化， 并与理想情况下的结果进行了对比。研究结果表明， 不考虑 透镜色差时， 一阶空间啁啾高斯脉冲光束经过透镜聚焦后仍然是一阶空间啁啾高斯脉冲光束； 透镜色差对一阶空间 啁啾高斯脉冲光束聚焦后的束宽和振幅耦合程度没有影响， 但会导致聚焦后光束的脉宽加宽。 关键词 激光光学； 高斯脉冲光束； 空间啁啾； 聚焦特性； 时空耦合； 色差 中图分类号 O436 文献标识码 AAbstract Spatial chirp is a common phenomena in ultrashort pulses. The focusing characteristics of Gaussian pulsed beams with the first-order spatial chirp (FSC) are investigated, and the analytical expression for the FSC beam on the output plane is derived. The analytical expressions for the pulse width, beam width and amplitude coupling coefficient of the FSC beam after focusing without chromatic aberration are derived. The intensity distribution before and after focusing is simulated. The pulse width, beam width and amplitude coupling coefficient of the FSC beam after focusing are analyzed numerically with the variation of propagation distance when the chromatic aberration is considered, which are compared with the corresponding results when the chromatic aberration is not considered. It is found that the FSC beam keeps the form after focusing without chromatic aberration; the chromatic aberration has no effect on beam width and amplitude coupling coefficient, but broadens the pulse width of FSC beam.

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