热成像仪由于工作环境较为恶劣，且自身发热量较大，容易导致热像仪光轴发生热偏移，严重影响其瞄准性能。为了提高红外热像仪的光轴热稳定性，以某型热像仪光轴敏感部件——折转镜为主要研究对象，研究其在不同环境温度条件下的光轴变化情况，并通过构建折转镜的有限元仿真模型以及试验测试系统，获得与试验数据一致性较好的有限元模型；以此为基础，采用基于变密度法的拓扑优化仿真技术，以刚度最大化为设计目标，以体积分数为约束，对折转镜座进行了拓扑优化设计。通过试验测试得出，优化设计的折转镜座的光轴高温偏移量由46.1″减小到25.5″，减小了44.7%，折转镜座的光轴低温偏移量由92.9″减小到51.0″，减小了45.1%，极大地提高了折转镜的光轴热稳定性。最后，将优化后的折转镜安装到某型热像仪中进行整机试验测试，热像仪整机的高温光轴偏移量由0.461 mrad减小到0.340 mrad，下降了26.2%，低温光轴偏移量由0.485 mrad减小到0.296 mrad，下降了39.0%，证明了仿真与拓扑优化模型的可行性与有效性，为后续红外热像仪整机的轻量化设计与性能提升奠定了基础。

The silicon on glasses process is a common preparation method of micro-electro-mechanical system inertial devices, which can realize the processing of thick silicon structures. This paper proposes that indium tin oxides (ITO) film can serve as a deep silicon etching cut-off layer because ITO is less damaged under the attack of fluoride ions. ITO has good electrical conductivity and can absorb fluoride ions for silicon etching and reduce the reflection of fluoride ions, thus reducing the foot effect. The removal and release of ITO use an acidic solution, which does not damage the silicon structure. Therefore, the selection of the sacrificial layer has an excellent effect in maintaining the shape of the MEMS structure. This method is used in the preparation of MEMS accelerometers with a structure thickness of 100 μm and a feature size of 4 μm. The over-etching of the bottom of the silicon structure caused by the foot effect is negligible. The difference between the simulated value and the designed value of the device characteristic frequency is less than 5%. This indicates that ITO is an excellent deep silicon etch stopper material.The silicon on glasses process is a common preparation method of micro-electro-mechanical system inertial devices, which can realize the processing of thick silicon structures. This paper proposes that indium tin oxides (ITO) film can serve as a deep silicon etching cut-off layer because ITO is less damaged under the attack of fluoride ions. ITO has good electrical conductivity and can absorb fluoride ions for silicon etching and reduce the reflection of fluoride ions, thus reducing the foot effect. The removal and release of ITO use an acidic solution, which does not damage the silicon structure. Therefore, the selection of the sacrificial layer has an excellent effect in maintaining the shape of the MEMS structure. This method is used in the preparation of MEMS accelerometers with a structure thickness of 100 μm and a feature size of 4 μm. The over-etching of the bottom of the silicon structure caused by the foot effect is negligible. The difference between the simulated value and the designed value of the device characteristic frequency is less than 5%. This indicates that ITO is an excellent deep silicon etch stopper material.

离轴四反系统是顺应多光合一机载观瞄系统未来发展的光机核心部件。该类型系统容易受到视场外部强杂散光的影响，系统杂散光的点源透射率（PST）一般要求不大于10⁻⁴量级，因此，对系统PST进行全方位扫描计算是分析和抑制其杂散光的关键。针对系统的非对称性，将PST作为随杂散光入射空间水平角和垂直角变化的二维函数，用以评价外部杂散光的影响，同时建立了水平角、垂直角与光机建模所需绕坐标轴旋转的过程量的对应转换关系，编制了仿真控制程序，通过调用LightTools软件实现杂散光的自动追迹和PST的二维扫描计算。对多光合一离轴四反系统，计算了整个入射半球空间内、所有方向的杂散光对应的PST分布情况，从而筛选出对机载观瞄应用影响较大的三路杂散光，寻找到其传输的路径和关键表面。基于此，设计了内部遮光罩和挡光环，优化系统内部的杂散光陷阱结构，使得系统的PST峰值由原来10⁻¹量级降低至10⁻⁴量级，在规避角范围以外小于10⁻⁷，可满足机载光电观瞄系统的使用要求。为离轴四反系统杂散光分析及抑制提供了依据。