用于高数值孔径物镜的可调光瞳滤波器

根据矢量衍射理论，提出了一种用于提高高数值孔径显微物镜纵向分辨率的可调二元环形光瞳滤波器，通过改变滤波器的环半径获得不同的纵向分辨率，并利用共焦显微术点扩散函数的乘积性大大地降低了旁瓣相对主瓣的比值。模拟结果表明，这种新型滤波器不仅可以提高高数值孔径物镜的纵向分辨率，同时基本上不影响横向分辨率。     

Investigation on the electric-field-induced Pockels effect and optical rectification in near-intrinsic silicon samples

Based on the classical polarization theory, we studied and specified the physical mechanism of the electric-field-induced (EFI) Pockels effect and optical rectification in the space charge region of a near-intrinsic silicon sample with the planar capacitor structure. Especially, the effect of the applied DC bias on these EFI effects was investigated. The results show that the electro-optic signal from Pockels effect in silicon linearly increases with the applied DC voltage and the modulating voltage, and the signal of optical rectification is linearly enhanced by the DC bias as well, but the polarization characteristic of optical rectification does not vary. The enhancement of these EFI effects is mainly owed to the strengthening of the built-in field and the extension of the space charge region in the silicon sample. The Kerr effect of silicon was also detected and contrasted against the EFI Pockels effect, and it is verified that the EFI Pockels effect is much stronger than the Kerr effect in the silicon sample. These EFI effects are significant for the development of silicon photonics or silicon optoelectronics.     

Experimentally distinguishing electro-optic effects in silicon

Different electro-optic effects, such as Kerr effect, Pockels effect induced by the electric field or strain, and plasma dispersion effect exist in silicon. Experimentally distinguishing these effects is necessary for designing silicon-based electro-optic devices. According to their different polarization dependencies and frequency responses, these effects are measured and distinguished successfully via a transverse electro-optic modulation experiment based on the near-intrinsic silicon sample. The results indicate that Pockels effect induced by the electric field or strain is primary among these effects in the near-intrinsic silicon sample.     

不同切型BaTiO3晶体二波耦合特性研究

分析了光折变晶体的电光系数对二波耦合特性的影响,二波耦合能量转移方向不仅依赖于晶体中光生载流子的电荷符号以及入射光与晶体ｃ轴的相对取向,而且依赖于晶体光系数各分量的相对大小;这种特性别明显地表现在相向二波耦合作用中。     

Imaging the Magnetic Reversal of Isolated and Organized Molecular‐Based Nanoparticles using Magnetic Force Microscopy

In the race towards miniaturization in nanoelectronics, magnetic nanoparticles (MNPs) have emerged as potential candidates for their integration in ultrahigh‐density recording media. Molecular‐based materials open the possibility to design new tailor‐made MNPs with variable composition and sizes, which benefit from the intrinsic properties of these materials. Before their implementation in real devices is reached, a precise organization on surfaces and a reliable characterization and manipulation of their individual magnetic behavior are required. In this paper, it is demonstrated how molecular‐based MNPs are accurately organized on surfaces and how the magnetic properties of the individual MNPs are detected and tuned by means of low‐temperature magnetic force microscopy (LT‐MFM) with variable magnetic field. The magnetization reversal on isolated and organized MNPs is investigated; in addition, the temperature dependence of their magnetic response is evaluated.     

Characteristic Features of Magnetization Reversal of Exchange Coupled Tb–Co/FeNi Film Structures in a Temperature Range Including the Compensation Point of the Ferrimagnetic Layer

Physics of the Solid State - The results of the study of the magnetic properties of exchange coupled Tb–Co/FeNi film structures obtained by magnetron sputtering in a wide range of...     

O-RPR网络中622 Mbps光上路源的研制

基于全光缓存器的光弹性分组交换环(O-RPR)是一种全光分组交换网络,能够克服目前RPR存在的电子瓶颈。为了模拟这种网络解决竞争的能力和解决网络的帧同步不丢失的问题,设计了一种基于FPGA的光上路源。它由数据包(帧)生成、并串变换和电光转换三部分组成,其包长、包内伪随机序列长度、及通信速率均可变,具有结构简单、成本低廉和操作方便的优点,已成功应用于O-RPR实验网络中。     

数码彩扩机色域匹配模型研究

色域匹配是数码彩扩机实现图像颜色较好再现的关键.首先,采用一种较为实用的方法对CRT显示器进行了标定,运用Beer色料理论预测了彩色相纸的色域.在此基础上,运用非线性压缩算法实现从CRT到彩色相纸的色域匹配,同时提出了虚拟色域的概念,并加以分析研究.结果表明,非线性压缩色域匹配模型对于建立数码彩扩机的颜色管理系统具有重要实用价值.采用这种方法在国家高新技术激光数码彩扩机中取得了高质量的扩印效果.