部分相干光束通过硬边光阑的推广光束传输M2因子

给出部分相干光通过硬边光阑后的强度二阶矩的计算公式，由此可得到部分相干光通过硬边光阑后的推广光束传输M^2因子。以部分相干高斯－谢尔模型光束为例，推导出相应的M^2因子，并作了数值计算和分析讨论。     

用正弦变频滤波器抑制孤子间的相互作用

提出用正统变频滤波器抑制孤子间的相互作用，并对上变频滤波器、下变频滤波器、交叉变频滤波器在抑制孤子相互作用方面的效应进行了数值研究。结果表明，正弦变频滤波器是最为有效的。     

The penetration, diffusion and energy deposition of high-energy photon

This paper presents a new theory for calculating the transport of high-energy photons and their secondary charged particles. We call this new algorithm characteristic line method, which is completely analytic. Using this new method we cannot only accurately calculate the transport behaviour of energetic photons, but also precisely describes the transport behaviour and energy deposition of secondary electrons, photoelectrons, Compton recoil electrons and positron-electron pairs. Its calculation efficiency is much higher than that of the Monte Carlo method. The theory can be directly applied to layered media situation and obtain a pencil-beam-modelled solution. Therefore, it may be applied to clinical applications for radiation therapy.     

Excited Stated in ^207Rn

Excited states ^207Rn are investigated via the^196Pt(^16O,Sn)^207 Rn reaction at beam energies from 85 to 95 MeV using techniques of in-beam γ-ray spectroscopy.Measurements of γ-ray excitation function,x-γ and γ-γ-t conincidences are performed with ten BGO(AC) HPGe detectors.Based on these measurements,a level scheme of ^207Rn,including 17 γ-rays and 18 levels,is established.Spins for most of the levels are proposed according to the measured DCO ratios.The level struccture is compared with a weak-coupling calculation using the interaction energies extracted from neighbouring nuclei.     

Investigation of External Optical Feedback Resistance of IC—DFB and GC—DFB Lasers Using a Very Simple Experimental set—up

We study the external optical feedback resistance of both index-coupled(IC) and gain-coupled distributed feed-back(DFB) lasers using a very simple experimental set-up.Though IC-DFB lasers with large coupling coefficients are found to be less sensitive to external reflection,they suffer from mode instability at high injection level.On the other hand ,the introduction of gain-coupling mechanism can significantly improve both the immunity of external optical feedback and the single mode yield of the device.     

A Powerful Simple Shooting Method for Designing Multi-Pumped Fibre Raman Amplifiers

A simple shooting method dedicated to the design of multipump discrete Raman fibre amplifiers (RFAs) ispro posed and discussed in detail. A novel scheme to provide a good initial guess for backward lightwaves is also proposed to improve the efficiency and robustness of the method. Using the proposed method, a discrete RFA with four backward pumps and 93 signal channels is simulated for the maximum number of interaction waves considered simultaneously in the RFA design reported previously; to our best knowledge. The numerical simulation results show that the proposed method is fast and robust. It can be used in the design of RFAs with various configurations including co-, counter- and bi-directJonal-pump schemes to provide an actual modelling.     

一种新型有机电致微腔结构的双模发射

采用结构Glass／DBR／ITO／NPB／NPB：Alq／Alq／Al制作了有机微腔电致发光器件。将空穴传输材料与发光材料以一定比例混合作为发光层，为了便于对比，在不改变有机层的膜厚的情况下同时制作了传统的异质结微腔器件，发现两种器件的发光光谱有很大不同，器件的复合效率与传统的异质结器件相比也得到了很大提高，这是因为将两种有机材料混合能消除界面势垒，提高器件的复合效率，从而提高了器件的发光性能，实现了微腔双模发射，且两个模式的半峰全宽分别为8nm和12nm。通过进一步优化器件结构可以实现微腔白光发射。     

三级近似束流光学计算程序

为了精确计算束流在离子光学系统中的传输,用Visual FORTRAN 6.5语言编写了一个计算程序,长约13000行. 此程序可以计算由三圆筒单透镜、三膜片单透镜、双元筒透镜、均匀场静电加速管、磁四极透镜、六极磁铁、静电四极透镜、偏转磁铁、螺线管透镜、ExB~正交电磁场分析器、静电偏转器、漂浮管、QWR(Quarter Wave Resonators)和SLR(Split Loop Resonators)射频加速元件等元件任意组成的离子光学系统. 粒子轨迹的计算可精确到三级近似. 粒子的分布类型也可以有多种选择. 程序具有最优化计算功能,即可以自动调整元件的参数,以实现所需要的光学条件. 各元件之后的横向和纵向相图以及系统的束流包络线以图形方式显示在屏幕上.     

Studies on fluorenscence resonance energy transfer between CdS nanoparticles and DOCAI dyes

The water-soluble CdS nanoparticles were synthesized in aqueous solution. A novel fluorescence resonance energy transfer (FRET) system with CdS nanoparticles as energy donors and 3,30-diethyl-oxadicarbocyanine iodide (DOCAI) dyes as energy accepter has been developed.