针对低轨小卫星星座的通信需求，设计了基于双棱镜和四象限雪崩光电二极管(QAPD)结构收发同轴的激光通信载荷，该方案是无信标光体制，具有体积小、轻量化和大视场的特点。文中针对双棱镜结构，给出了双棱镜输入输出光线的计算模型，在此基础上，提出了星间指向、捕获和跟踪的实现方式，并在XY-2号卫星上进行了在轨测试和验证，进行指向测试时，更新了指向偏移量，标定了QAPD跟踪点，并进行了双向建链测试。进行了15次双向建链测试表明，该激光通信载荷捕获时间小于20 s，捕获成功率达到100%，捕获后双星建链时间优于2 s，建链测试成功率达到了93%，建链后跟踪精度RMS值小于30 μrad。

Zinc strontium phosphate glasses doped with different trivalent praseodymium ion (Pr3+) concentrations are presented and their photoluminescence properties are investigated upon 442 nm excitation. With the Pr3+ concentration decreasing, the orange emission of Pr3+ (D21 HJ3) is enhanced steadily at the cost of its blue emission (P1,03 H43). Monochromic orange emission of Pr3+ ions is obtained when the Pr3+ doping is reduced to 0.05 mol.%. The mechanism controlling the monochromatic characteristic of Pr3+ emissions is supposed to be associated with the phonon-aided nonradiative relaxation process of Pr3+: Pj3→250.5230 Photoluminescence 160.2750 Glass and other amorphous materials 160.5690 Rare-earth-doped materials 300.2140 Emission