同时测量物体五维几何偏差的新方法

详细分析了基于激光全息技术,激光准直技术,激光光束漂移补偿技术和磁光调制补偿技术的综合运行,以单一激光束为基准,同时测量物体五维偏差的基本原理。通过标定和实验测量,在激光光源距测量靶标１ｍ时,该测量系统σ精度为：线位移〈２μｍ角位移〈４″。     

位相板衍射准直研究

本介绍了在大尺寸测量情况下,利用半导体激光光纤和位相板衍射技术进行准直的原理和方法,理论上分析了高斯光束通过位相板后衍射光场的特点,提出并分析了影响该原理精度的因素,从理论上分析并用计算机仿真验证了该原理在大尺寸形位误差测量中的可行性。     

长距离高精度激光准直技术的最新发展

激光准直技术已广泛应用于大型工件直线度、同轴度、平面度等形位误差的测量.本论文主要介绍近年来激光准直技术的最新发展,如反馈控制法、无衍射光莫尔条纹法等.这些激光准直技术从理论到实践都较好地克服了激光漂移、大气环境对激光准直的影响,较好地满足了长距离高精度形位误差测量的要求.     

采用液晶光阀的氦氖激光准直控制

激光光束的漂移,功率稳定性和激光光斑的强度分布对称性是影响准直精度的主要参数。通过分析液晶光阀的特性,提出了一种智能型光束准直控制方法,可同时控制激光功率的稳定性和光斑的强度分布对称性。利用热平衡技术,设计了一套温度实时反馈控制的准直装置。实验结果证实了该方法的可行性和有效性。     

基于DPGC技术的激光干涉纳米振动测量系统

基于数字相位载波调制(DPGC)原理,建立了激光干涉振动测量系统及其信号解调的软硬件处理平台,以24位数字信号采集卡配合64位PC处理器作为硬件电路的核心,实现了参考波形的发生与待测信号的实时采集,利用LabVIEW软件平台构建了DPGC算法,实现了振动信号的实时解调.实验结果表明,基于PC平台的DPGC信号解调方法,降低了传统的模拟PGC技术中模拟乘法器和微分器等硬件电路的漂移和噪声,提高了信号解调精度,改善了系统信噪比,实现了对频率范围10～200Hz低频振动信号的高精度测量,其分辨力达到0.14nm,动态范围达到120dB.     

Mach-Zehnder光纤干涉仪相位载波调制及解调方案的研究

本文根据Mach Zehnder光纤干涉仪相位调制与双光束干涉测量的特点 ,提出了一种采用相位调制器 (PZT)实现相位载波调制 ,利用贝塞耳函数进行傅里叶分解实现相位调制信号解调的检测方案。理论分析表明 ,该方案能有效地抑制随机干扰信号对测量精度的影响     

电梯导轨表面轮廓的在线检测与分析系统

该系统包括PSD,激光垂直准直器,数据采集箱和应用软件四个部分。激光准直器发出的 光分为两路:一路用于建立测量的垂直基准;另一路用于补偿光束的随机漂移。与导轨紧密相连的PSD用来检测导轨表面与垂直基准的距离变化。实验结果显示:使用降噪技术后,系统在50米测量范围内精度达40m,导轨直线度标准差也减小。     

高精度激光准直技术的研究（一）

论述了激光准直技术的发展及共性的技术关键问题，系统介绍了对单位在高精度激光准直技术方面的研究成果，从理论到实践较好地克服激光漂移，大气环境对激光准直的严重影响。研制成功的激光光纤准直仪，激光双频同轴度仪及激光旋光准直仪具有当前高精度激光准直技术的代表性，并且均达到国内外先进水平。     

相位调制干涉位移测量系统信号处理方法

为克服激光干涉位移测量系统中直流漂移等低频扰动影响,采用相位调制方法,将有用信号频带移出低频区.对干涉信号,通过乘法操作将被测位移信息变换到调制频率2.5倍频谐波分量的相位上,并利用锁相环解调位移信息.搭建Simulink仿真模型,验证信号处理方法的可行性.结合仿真结果分析直流分量、交流分量幅值等参数对解调结果的影响.结果表明,采用的信号处理方法理论上克服了调制频率对最大测量速度的限制,仿真系统对临界加速度以内的加速信号有良好的追踪能力.     

IFOG中相位调制器的残余强度调制及其测量

利用开环正弦波调制解调方法,推导了铌酸锂相位调制器的残余强度调制(简称RIM)对干涉型光纤陀螺(简称IFOG)信号的影响,指出在调制频率漂移或光纤环渡越时间变化时RIM可导致陀螺的零偏和噪声增大.对典型条件的计算表明,0.01°/h的IFOG容许的最大RIM为13ppm,0.1°/h的中低精度IFOG则为81ppm.提出利用锁相放大器精确测量相位调制器RIM的方法,并对国产器件进行测量,结果表明,器件RIM指标可在中低精度IFOG中应用.     

Synthesis of carboxyl-capped and bright YVO4:Eu,Bi nanoparticles and their applications in immunochromatographic test strip assay

Carboxyl-capped YVO₄:Eu,Bi nanoparticles with average diameter of ∼10 nm were synthesized via a copolymer of phosphono and carboxylic acid mediated hydrothermal method. Under a 350 nm ultraviolet light excitation, the YVO₄:Eu,Bi NPs exhibit sharp and bright red emission peaked at 615 nm and with highest quantum yield of ∼43%. Furthermore, the nanoparticles show good water/buffer stability and feasible bioconjugation benefiting from the carboxylic groups on their surface. Based on these kind optical and surface properties of the YVO₄:Eu,Bi nanoparticles, an immunochromatographic test strip assay for quantitative determination of human IgG was achieved. This protocol can be extended to other rare-earth nanoparticles with the purpose of developing bioprobes for desired applications.     

带宽〉40nm的980nmLD泵浦掺Er^3＋光纤放大器模块

在国内首次用９８０ｎｍ激光二极管和参量优化Ｅｒ３＋／Ａｌ３＋共掺杂光纤研制成光学带宽＞４０ｎｍ的光电一体化光纤放大器实用型模块样机。模块净增益２５ｄＢ，饱和输出功率０ｄＢｍ，最大输出功率８ｄＢｍ，噪声系数＜５ｄＢ，可供波分复用光纤通信系统和光孤子传输实验试用。     

Planar optical waveguides in Nd:BSO crystals fabricated by He and C ion implantation

Planar optical waveguides in Nd:BSO crystals were fabricated by the implantation of 500 keV He ions and 6.0 MeV C ions at two different substrate temperatures. The guiding modes were measured by the prism-coupling method with a He-Ne beam at 633 nm. The intensity calculation method (ICM) and reflectivity calculation method (RCM) were used for reconstructing refractive index profiles. The near-field intensity distribution of the waveguide, formed by He and C ions implanted after annealing at 300 °C, was measured by the end-face coupling setup. It was in reasonable agreement with the intensity of the waveguide mode simulated by the finite-difference beam propagation method (FD-BPM). The absorption spectra of the sample with He ions implanted at fluences of 3 × 10¹⁶ ions/cm² were measured using a spectrophotometer.     

Bandgap and exciton binding energies in lead-iodide-based natural quantum-well crystals

We have performed optical absorption and electroabsorption studies on the lead-iodide-based natural quantum-well perovskite-type crystals with different well width (C₆H₁₃NH₃)₂(CH₃NH₃)_m−1Pb_mI_3m+1. With decreasing well thickness, m, the resonance energies of the lowest-energy excitons shift to higher energy due to the increase of the bandgap. The binding energies and oscillator strengths of the excitons drastically increase due to the spatial confinement and image charge effect with decreasing m. The bandgap of (C₆H₁₃NH₃)₂(CH₃NH₃)_m−1Pb_mI_3m+1 (m≥2) can be reproduced by the effective-mass approximations, while the effective-mass approach is not valid for (C₆H₁₃NH₃)₂PbI₄ (m=1).     

Influence of calcination ambient and film thickness on the optical and structural properties of sol-gel TiO2 thin films

Influence of both calcination ambient and film thickness on the optical and structural properties of sol-gel derived TiO₂ thin films have been studied. X-ray diffraction results show that prepared films are in an anatase form of TiO₂. Films calcined in argon or in low vacuum (∼2 × 10⁻¹ mbar) are found to be smaller in crystallite size, more transparent at low wavelength region of ∼300-450 nm, denser, have higher refractive index and band gap energy compared to air-calcined films. Scanning electron microscopic study reveals that surfaces of TiO₂ films calcined in argon or in low vacuum are formed by densely packed nano-sized particulates. Presence of voids and signs of agglomeration can be seen clearly in the surface microstructure of air-calcined films. In the thickness range ∼200-300 nm, band gap energy and crystallite size of TiO₂ films remain practically unaffected with film thickness but refractive index of thinner film is found to be marginally higher than that of thicker film. In this work, it has been shown that apart from temperature and soaking time, partial pressure of oxygen of the ambient is also an important parameter by which crystallite size, microstructure and optical properties of the TiO₂ films may be tailored during calcination period.     

用光学方法研究掺硼 a-Si_(1-x)C_x∶H 膜的隙态密度

用光透射法测得了 p-a-Si_(1-x)C_x∶H 膜的隙态密度。对于与隙态有关的弱吸收区,利用 Mott-Davis 近似和隙态为高斯分布的假设,得到了远离平衡费米能级处的隙态分布。对于未掺杂和轻掺杂样品,隙态高斯分布的峰值 N(E_t)约为10~(18)/cm~3·eV 的数量级,随着掺 B 量的增加 N(E_t)也增大。     

Doping effects on the optical properties of evaporated a-Si:H films

Thin films of a-Si:H are deposited on substrates at 300°C by a conventional thermal evaporation technique. The electrical conductivity of these films is modified by the addition of antimony giving n-type films. The optical properties of the films are investigated using spectrophotometric measurements of the transmittance and reflectance in the wavelength range 200–3000 nm. Both the refractive index n and the absorption coefficient increase when the Sb content is increased. The absorption edge shifts to lower energies for doped films. The optical gap E_g is evaluated using three different plots for comparison, namely; (hν)^1/2, (/hν)^1/2 and (hν)^1/3. The value of E_g decreases with doping for the three expressions. The Urbach parameter E₀ is calculated and found to increase with doping from 74 meV for the undoped film to 183 meV for concentrations of 9.4 at.% Sb.     

Influence of deposition regime on physical properties of gallium doped zinc oxide films

Zinc oxide films doped by gallium were deposited using RF diode sputtering from a ceramic ZnO + 2% Ga₂O₃ target on Corning glass in argon atmosphere. Samples were supported in three different positions against a substrate holder - horizontal, and at 60 and 80° to the horizontal position. Two series of samples 700-1000 nm in thickness were prepared: one at room temperature (RT) and the second at 200 °C. XRD, optical and electrical experiments indicated that the films are polycrystalline having average crystallite sizes from 30 to 80 nm, integrated transmittances in the range of 400-1000 nm increased from 85 to 90 per cent and optical band-gap values increased from 3 to 3.2 eV with higher deposition temperature. The resistivity of the obliquely sputtered samples positioned at 80° to the substrate holder was one order lower than the horizontally positioned samples. No significant changes were observed in case of optical properties of the films in dependence on the tilt-angle.     

Development of spectroscopic ellipsometry as in-line control for Co SALICIDE process

This work is aimed at in-line thickness and composition analysis of Co silicides by spectroscopic ellipsometry (SE). The silicides were formed by a two-step rapid thermal annealing (RTA) in nitrogen at different temperatures from initial Co layers deposited on Si (100) substrates and capped by a protective layer of TiN. The optical constants of Co, CoSi and CoSi₂ films were calculated in the wavelength range of 240–800 nm, describing the optical dispersions by harmonic oscillator models. These models were applied for in-line thickness and composition control of the main steps of Co SALICIDE process. The effects of the first RTA temperature and initial Co thickness on formation of silicide phases and their thickness were evaluated. For phase identification, additional methods (sheet resistance, Auger electron spectroscopy and X-ray diffraction) were used. Finally, the suitability of SE for layer thickness uniformity evaluation was demonstrated for the main steps of Co SALICIDE process.     

The inherent optical nonlinearities of thin silver films

Thin Ag films with the thickness of 80 Å were prepared by pulsed laser deposition technique. The films were grown on MgO(1 0 0) substrates under the nitrogen pressure of 5.0 Pa at room temperature. The surface images of the films were observed by atomic force microscopy. The linear optical properties of the films were studied in the wavelength range of 300–800 nm. The inherent third-order nonlinear optical responses coming from the silver material itself were determined by z-scan method at the wavelength of 532 nm with laser duration of 10 ns. The significant optical nonlinearities of the pure thin Ag films were determined to have the real and imaginary parts of the third-order nonlinear optical susceptibility (χ⁽³⁾) as 2.49 × 10⁻⁸ and 7.16 × 10⁻⁹ esu, respectively. The obtained χ⁽³⁾ value of Ag films was about one order of magnitude larger than that of Ag colloids.