中文摘要：

地球同步轨道（GEO）星地激光通信终端为开敞式结构,其光通信天线裸露于卫星舱外,受交变剧烈的空间外热流影响,光通信天线符合温控要求的在轨有效工作时间每天仅有4~6h。基于现有热控技术基础,通过对太阳窗的设计削弱空间外热流的影响,改进系统热稳定性,并基于有限元分析得到使光通信天线系统热稳定性最佳的太阳窗光热特性参数优化设计,使其满足太阳透射率较高、吸收率较低,并且内、外表面红外发射率均较高的要求。采用上述太阳窗优化设计,光通信天线次镜可全天候满足温度指标,主镜全天中满足温度指标的时间可达12h,二者有效工作时间分别为基础方案（未采用太阳窗）的3倍和2倍。

英文摘要：

The geostationary earth orbits （GEO） satellite-borne laser communication terminal is of an open-type structure and the laser communication antenna is uncovered out of the satellite. The effective operation time of the antenna is only 4 to 6 hours per day due to the strictly alternate orbital heat flux changing. The solar window is designed to weaken the effect of the orbital heat flux and to improve the thermal stability of the laser communication antenna based on existing thermal control technology, and the optimal design of the optical and thermal properties is obtained by the finite element analysis method as the thermal properties of the laser communication antenna is most stable. The solar window has a larger solar transmission, smaller absorption and larger infrared emissivity for inner and external surfaces. The laser communication antenna secondary mirror can meet the temperature index on whole day and the main mirror can he used for 12 hours per day by utilizing the optimal designed solar window. The effective operation time of the secondary mirror and the main mirror are twice and triple respectively as much as the time of the basic case without the solar window.