研究静态空气中多点激光诱导等离子体的演化特性是研究和优化其超声速稳燃效果的基础。在常规的试验研究中，由于测量手段和试验设备的限制，可以获取的静态空气中多点激光诱导等离子体的后流场信息有限，且激光焦点构型单一。本文采用改进后的Dors模型，对静态空气中多点激光诱导等离子体的演化特性开展了数值模拟研究。基于数值纹影图、温度等值面图、流场压力和温度分布规律图，阐释了静态空气中线形激光焦点构型的多点激光诱导等离子体产生的激波、等离子体内核以及流场相关参数的演化特性；随后通过对等离子体内核的平均温度、体积、比表面积以及流场特征位置的压力进行分析，得到了激光焦点布局形式和间距对多点激光诱导等离子体演化特性的影响规律。结果表明，当激光焦点间距较小（2~4 mm）时，激光焦点间距是影响演化特性的主要参数。

用高温固相法制备了一系列 2 at.% Dy3+ 和 x at.% Eu3+ (x=0,0.1,0.5,1,2,5) 共掺 NaY(MoO4)2 样品。X 射线衍射 (XRD)、 扫描电子显微镜 (SEM) 及红外光谱 (FTIR) 表征结果表明所合成的样品为四方相结构, 空间群为 I41/a。进一步研究了样品的激发光谱和在近紫外光激发下的发射特性, 结果表明 Dy3+ 和 Eu3+ 之间存在能量共振传递, 从而增强了 Eu3+ 的发光。2 at.% Dy3+ 和 2 at.% Eu3+ 共掺样品的 CIE 色度坐标值 (x=0.659,y=0.338) 接近 NTSC 规定的标准值, 因而有望作为显色性能优良的发光材料用于固态照明领域。此外， NaY(MoO4)2 物化性能稳定, 易采用提拉法生长, 因此本研究结果可以为 Dy3+ 和 Eu3+ 共掺 NaY(MoO4)2 单晶生长以及蓝紫光泵浦可见激光特性研究提供参考。

With the rapid development of life sciences, there is an increasing demand for intravital fluorescence imaging of small animals. However, large dimensions and limited working distances of objective lenses in traditional fluorescence microscopes have limited their imaging applications mostly to superficial tissues. To overcome these disadvantages, researchers have developed the graded-index (GRIN) probes with small diameters for imaging internal organs of small animals in a minimally invasive fashion. However, dynamic imaging based on GRIN lens has not been studied extensively. Here, this paper presented a fluorescence endoscopic imaging system based on GRIN lenses using one-photon and two-photon excitation. GRIN lenses with 1.15 mm diameter and 7.65 mm length were used in the system. The images were acquired by a compact laser scanning imaging system with a resonant galvo-mirror system to scan the laser beam and a photomultiplier tube (PMT) to detect fluorescence signals. Experimental results showed that this system using two-photon excitation could implement dynamic fluorescence microendoscopic imaging and monitor the movement of blood flow beneath the skin in anesthetized mice while producing images with higher contrast and signal to noise ratio (SNR) than those using one photon excitation. It would be a useful tool for studying biological processes of small animals or plants in vivo.

采用四象限探测器和功率谱密度法，搭建了一套快速标定光镊三维光阱刚度的测量系统.实验中，用四象限探测器记录微粒做受限布朗运动时的位置信息，用功率谱密度法标定光阱刚度，测得了直径0.97 μm SiO2小球和直径1 μm PMMA小球的光阱刚度与激光功率的关系.结果表明：对于SiO2小球，当激光功率为50~120 mW时，光阱刚度与激光功率成正比；对于PMMA小球，当激光功率为80~130 mW时，光阱刚度与激光功率成正比.该光镊系统可用于生物、物理等微观领域研究的高准确度测力系统.

Bessel beam propagation in scattering media is simulated using the angular spectrum method combined with slice-by-slice propagation model. Generating Bessel beams with a spatial light modulator, which provides a means to adjust flexibly the parameters of the Bessel beam, allows us to validate the simulation results experimentally. The study reveals that the self-reconstructing length changes oppositely with the axicon angle (i.e., the larger the axicon angle, the shorter the self-reconstructing length). The radius of the incident beam has little influence on the self-reconstruction of the Bessel beam central lobe.

Dual-channel phase-shifting interferometry for simultaneous phase microscopy is presented. Red and blue light beams are used for microscope illumination. A 45o tilted beamsplitter replicates the object and reference waves in red light together with the object wave in blue light into two parallel beams. The two resulting quadrature phase-shifting interferograms in red light and the object waves in blue light are generated in the two channels. The two interferograms are recorded simultaneously by a color charge-coupled device (CCD) camera, and can be separated via RGB components of the recorded color patterns without crosstalk. As a result, the phase of tested specimen can be retrieved. The feasibility of the proposed method is demonstrated by test performed on a microscopic specimen.

An on-axis phase-shifting reflective point-diffraction microscopic interferometer for quantitative phase microscopy based on Michelson architecture is proposed. A cube beamsplitter splits the object wave spectrum into two copies within two arms. Reference wave is rebuilt in one arm by low-pass filtering on the object wave frequency spectrum with a pinhole-mask mirror, and interferes with the object wave from the other arm. Polarization phase-shifting is performed and phase imaging on microscale specimens is implemented. The experimental results demonstrate that the proposed scheme has the advantage of long-term stability due to its quasi common-path geometry with full use of laser energy.