在深空探测中，以微波为载体的通信、测距载荷面临链路损耗大、频谱资源紧张等问题。相比微波，激光光束发散角小，能量更为集中，可达更远的传输距离，以激光为载体的通信、测距载荷具有体积小、质量轻等优势。搭建了一套激光相干外差扩频通信测距一体化深空探测系统，提出了一种基于曲线模型的插值重采样方法，并对该曲线模型进行了理论仿真和实验验证。该模型由系统先验信息构建，是伪随机码相位差的线性函数。实验结果表明，对于静态目标，测距偏差不超过0.55 mm，测距精度不超过0.42 mm。对于动态目标，测距偏差不超过0.59 mm。静态和动态目标测距中实现了零误码通信。此外，扩频通信测距一体化设计应用于深空导航和深空时频同步，可以提高实时性。

卫星相干激光通信系统中，信号调制格式以相移键控（PSK）为主，未兼容开关键控（OOK）的相干接收。针对卫星相干光通信接收机不兼容多种调制格式的问题，实验搭建了兼容OOK以及二进制相移键控（BPSK）的相干通信接收装置。在1 Gbit/s的通信速率下，当调制格式为OOK且信号光功率为-54.6 dBm时，误码率（BER）为10^-3，接收灵敏度距离散粒噪声极限3.3 dB；当调制格式为BPSK且信号光功率为-57.95 dBm时，BER为10^-3，接收灵敏度距离散粒噪声极限4.2 dB。该多体制兼容相干接收机的结构与当前大多数相干接收机的硬件通用，且具有较高的接收灵敏度，证明了卫星相干激光通信多体制兼容技术的可行性，具有重要意义。

针对旋转双棱镜系统指向误差较大、误差源较多等指向精度较差的问题，提出了一种新的旋转双棱镜指向偏差修正方案。采用非近轴光线追迹方法建立旋转双棱镜指向模型和二维转台指向模型，在全视场区域内均匀选取若干点，比较旋转双棱镜理论出射光束与实际出射光束的偏差，通过Levenberg-Marquardt迭代算法对旋转双棱镜前镜和后镜的转角误差、楔角和折射率进行修正。在整个视场区域内修正后，指向最大偏差由8.37 mrad变为3.75 mrad，平均指向偏差由4.00 mrad变为1.38 mrad，并且当俯仰角较小时，修正效果较好；在俯仰角小于15°的视场区域进行单独修正后，最大指向偏差变为1.51 mrad，平均偏差变为0.84 mrad。所提修正方法提高了旋转双棱镜的指向精度，对旋转双棱镜指向偏差的补偿修正具有一定的参考价值。

随机并行梯度下降（SPGD）算法是一种应用广泛的最优化算法，在光学相控阵的多光束相位调控中具有重要作用。常规的SPGD算法在光学相控阵单元数目较大的应用场景下存在着迭代步数多、收敛速度慢等缺陷。为此提出了一种分级SPGD算法，将多光束进行分级，通过在多级使用SPGD算法对光束的调控来实现快速收敛和稳定维持。介绍了该算法的理论模型和流程，运用数值仿真的方式与传统算法进行了性能比较，结果表明，分级SPGD算法能够在大规模光学相控阵中显著提高收敛速度。搭建了光学相控阵实验系统进行分级SPGD算法的原理和可行性验证，在不同光束数目条件下实现了分级SPGD算法的闭环锁相，验证了算法的优越性，结果显示分级算法在32路光束时可以将迭代次数降低到常规算法的59.6%。

Combing the time-correlated single photon counting (TCSPC) with fluorescence lifetime imaging microscopy (FLIM) provides promising opportunities in revealing important information on the microenvironment of cells and tissues, but the applications are thus far mainly limited by the accuracy and precision of the TCSPC-FLIM technique. Here we present a comprehensive investigation on the performance of two data analysis methods, the first moment (M1) method and the conventional least squares (Fitting) method, in quantifying fluorescence lifetime. We found that the M1 method is more superior than the Fitting method when the lifetime is short (70 ~ 400 ps) or the signal intensity is weak (<103 photons).

A feasible method of combining the concept of fluorescence half-life and the power dependent photobleaching rate for characterizing the practical photostability of fluorescent proteins (FPs) was introduced. Furthermore, by using a fluorescent photostability standard, a relative comparison of the photostabilty of FPs from different research groups was proposed, which would be of great benefit for developing novel FPs with optimized emission wavelength, better brightness, and improved photostability. We used rhodamine B as an example to verify this method and evaluate the practical photostability of a far-red FP, mKate-S158C. Experimental results indicated good potential of this method for further study.

The second-order nonlinear optical characteristics of a novel organic crystal, urea L-malic acid (ULMA), were studied. Both type I and type II phase-matching angles of the biaxial crystal ULMA were calculated, whose loci are in the Hobden class 9. The efficiencies of second harmonic generation (SHG) of ULMA and KDP at a fundamental wavelength of 1064 nm were compared by using the Kurtz powder method. The results showed that the nonlinear coefficient of ULMA is about 1.57 times of that of KDP. High SHG efficiencies were observed over a broad range of the spectrum when ULMA was pumped by outputs generated from an optical parameter oscillator. To our knowledge, it is the first report where continuous SHG at fundamental wavelengths from 1300 to 950 nm with ULMA was achieved.