黑体模拟器

根据黑体光壁腔观点，用几何光学方法模拟黑体，得一维齿腔黑体模型，其发射率ε＝０．９９９９９９９９，给出黑体模拟数学式及实用黑体模拟器的几何参数。     

五锥黑体腔

用一特殊光路模拟黑体，将一个简单的三锥腔变成五锥式黑体模拟器。在尺寸不大的情况下设计发射率ε为０．９９９９９的黑体模型。给出黑体模拟数学式和适用模型的几何参数。     

二锥黑体腔

用一特殊光路模拟黑体，将简单的二锥腔变成黑体发射率为０．９９９９９的黑体模拟器。给出黑体模拟数学式和适用模型的几何参数。     

单倒锥优质黑体模拟器

提出在简单的倒锥腔中，用几何光学方法模拟黑体，得到发射率ε高达５０个９以上的黑体模拟器，并给出黑体模型设计公式及其设计结果。     

优质简易黑体模型

在普通二锥腔的柱壁上开小锥角Ｖ形沟槽，获得ε值高达０．９．．．９９（共２８个９）以上的黑体模拟器，给出黑体模拟数学式及实用黑体模型的几何参数。     

名词

黑体在任何温度下对所有波长的电磁辐射的光谱吸收比恒为1的辐射体，亦称绝对黑体．黑体在自然界并不存在，只是一种理想化的模型，但可用人工制作接近于黑体的模拟物．把一封闭空腔开一小孔，光穿过小孔进入空腔后，在空腹内壁反复反射，重新从小孔射出的机会极少，即使有机会从小孔射出，由于经历了多次反射而损失了大部能量．对空腔外的观察者来说，小孔对任何波长电磁辐射的光谱吸收比都接近了1，故可看作是黑体。将基尔霍夫辐射定律应用到黑体，有r。（．T）＿～～5。rn（尺，T）＝f（几，T）．QO（，7，）可见，基尔霍夫辐射定律中…     

串联倒锥式黑体模型

根据黑体镜腔特征，用几何光学方法模拟黑体得一串联倒推式黑体模拟器，推导黑体模拟数学式，给出适用模拟器参数。     

柱隙锥齿型黑体模拟器

持黑体光壁腔观点用几何光学方法模拟黑体，得一柱隙锥齿型黑体模拟器，写出黑体数学模拟式，给出适用模拟器的身体参数。     

表面结构对面源黑体光谱发射率的影响

随着红外测温技术的快速发展,红外测温仪在军事及民用领域得到广泛应用,对测量准确度的要求提升到了新的高度。面源黑体辐射源作为非接触测温设备校准的核心装置,近年来受到广泛的关注。发射率是描述辐射源性能的重要指标,目前缺少黑体表面形貌对发射率影响的研究。面源黑体发射率主要由表面凸锥结构和涂覆涂层决定。为设计出高发射率面源黑体,以具有凸锥结构的面源黑体为基础模型,引入间距及涂层结构,建立具有不同表面结构参数、单元间距及涂层厚度的面源黑体模型,设置基底材料为石墨,涂层材料为氮化硅,通过有限元软件得到仿真模型的反射率,利用反射率反演得到其发射率,绘制3～14μm范围内的光谱发射率曲线;研究面源黑体表面的电场分布情况。分析结构单元的宽高比、涂层厚度和结构单元间距等参数对发射率的影响。结构单元高度与发射率成正比、较窄的宽度对发射率有优化作用,发射率随宽高比的减小而增大。涂层结构改变了光谱发射率的下降趋势,在11μm后发射率上升,发射率随厚度增加而增大;单元间距变化与发射率成正比。设置初始面源黑体单元结构高度为10μm、宽度为1μm,在该模型上依次添加2μm涂层及2μm间距结构,进行仿真计算。优化后黑体...     

微机扫描黑体辐射实验研究

利用微机扫描光栅光谱仪和溴钨灯进行黑体辐射实验研究，验证了黑体辐射的基本规律；论证了黑体辐射实验方法的可行性，分析了黑体的辐射、传递和接收以及正弦机构等器件的性能和误差修正问题．     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Hybrid Wavelength and Code Division Multiple Access in Optical Networks

A review of schemes for multiple access in fiber optic networks shows that a hybrid of wavelength and code division multiple access (WCDMA) combines the best features of both. In particular, the hybrid scheme retains the large information carrying capacity of wavelength division multiple access (WDMA) and flexibility of code division multiple access (CDMA). In this paper WDMA, optical CDMA (OCDMA), and WCDMA networks are discussed. In OCDMA networks, concept of incoherent and coherent coding including inverse decoding and matched filter is introduced. The delay performance of both WDMA and WCDMA networks, under the simple suboptimum access protocols based on cyclic search, is computed. It has been shown quantitatively that tuning delay significantly affects the delay performance of both WDMA and WCDMA networks. Futhermore, delay performance of WCDMA networks is always better than the WDMA networks for the same tuning delay, load, and number of users.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Research on beamforming method for dual-line array with space mismatch between the two line arrays

The performance of port/starboard discrimination of dual-line array will be seriously degraded when the space between the two line arrays of the dual-line array is mismatched. The directivity function of the delay-sum and delay-subtract beamforming is deduced and the port/starboard discrimination of the delay-sum and delay-subtract beamforming is also studied both under the ideal status and the status under which the space between the two line arrays of the dual-line array is mismatched. Analysis results show the delay-subtract beamforming has better performance of port/starboard discrimination. At last, the sea trial results demonstrate the theoretical results.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.