近衍射极限半导体激光束波面检测

在星间半导体激光通信系统中，如何检测发射光束波面的质量是个较难处理的问题，为了较好地解决这一问题，在简单介绍白光横向双剪切干涉仪的基础上，报道了用此干涉仪对近衍射极限半导体激光光束波面的检测，在此基础上推导出计算远场发散度的公式。实验测得近场光束的波高差为0．2A，通过夫朗和费衍射求得光束的发散度仅为64．8μrad，这表明光束接近光学衍射极限。同时，表明双剪切干涉仪灵敏度高、实用性好。

狭缝投影位置传感技术及其在精密定位中的应用

提出了一种基于狭缝投影的位置传感技术，阐述了此技术的传感原理及其在精密定位中的应用。准直激光束照明的投影狭缝由一个透镜以掠入射角度投影在被测物体上，狭缝投影经过被测物体表面的反射和另一个透镜的成像在探测双缝上形成投影狭缝像。探测双缝放大成像在双像限探测器上，投影狭缝像透过探测双缝的光强分别被双像限探测器的两个像限所接收，通过检测双像限探测器两个像限上的光强获得被测物体的位置。实验验证了此传感技术的可行性，其位置重复测量偏差小于32nm（1σ）。

Measurement of small vibration amplitudes of a rough surface by an interferometer with a self-pumped phase-conjugate mirror

The application of a Michelson interferometer with a self-pumped phase-conjugate mirror to measure small vibration amplitudes of a rough surface is described. The distorted wave front of the light that is diffusely reflected from the rough surface is restored by phase conjugation to provide an interference signal with a high signal-to-noise ratio. The vibration amplitudes of a stainless-steel sample are measured with a precision of similar to 5 nm. (C) 2000 Optical Society of America OCIS codes: 120.3180, 190.5040, 120.7280.

图像深度估计的光学微分方法

讨论了光学微分方法在图像深度估计问题中的应用。基于线性成像理论对Farid提出的光学微分模型进行了推广，即用于图像深度估计的两幅图像在成像过程中可以满足任意阶的线性微分关系。此模型拓宽了光学微分的概念，使两次成像之间关系有了更多的光学微分形式。围绕如何选择合适的光学微分关系以使系统的整体性能达到最优，分析了光学成像系统的参量对于图像深度估计的精度以及纵向分辨力的影响，并且对光学微分方法中的关键光学元件—光学掩模板的构建方法及优化问题也作了初步的探讨。

精确标定光弹调制器的新方法

针对现有光弹调制器标定方法的不足，提出了一种精确标定光弹调制器的新方法。首先利用起偏器、波片、光弹调制器和检偏器构成标定光路．通过寻找探测信号基频分量的极大值进行粗略标定，使光弹调制器的峰值延迟量处在1．841rad附近。然后撤走波片形成光弹凋制器的精确标定光路．在检偏器旋转90°前后获得探测信号的直流分量和二次谐波分量。最后利用这两种探测信号的直流分量和二次谐波分量精确地计算出光弹调制器的峰值延迟量。实验验让了此光掸调制器标定方法，实验结果表明其标定误差仅为0．7％。在此光掸凋制器标定方法中．光弹调制器

精密光束偏离装置棱镜组件的光机热分析

以精密光束偏离装置的棱镜组件为有限元模型，进行了光机热集成分析．对棱镜组件的结构强度进行了校核，分析了机械载荷作用下的镜面变形；通过模态分析，给出了装置的动态特性和镜面面形振动幅值的变化情况；最后对棱镜的热弹性变形进行了分析，对棱镜的光学性能进行了评价．结果表明：棱镜组件的最大变形在10nm量级，最大应力为0．403MPa，应力和应变相对于结构的准确度要求和材料的许用应力具有较大的裕度；前后棱镜组件的固有频率都大于550Hz，装置具有良好的动态性能；通过对比棱镜在热-结构耦舍分析和机械载荷下的分析结果，说

大型干涉仪镜子的支承设计与温度变形分析

在星间激光通信中，涉及对大口径衍射极限激光波面的检测，为保证测量精度，必须严格控制波面十涉仪镜子的自重和温度变形。采用有限元方法对大型干涉仪镜子在不同支承方式下的表面变形进行了分析，结果表明，接触角为180°的钢带支承是较好的支承方式，反射镜表面变形峰-谷(P-V)值仅为1．35nm，均方根(RMS)值为0．363nm根据这一结论，设计了一个同定支承点与浮动支承相结合的超静定钢带支承结构。在该结构下，分析了镜子轴向、径向、周向的温度梯度效应，分析数据表明，镜子的热弹性变形远大于自重变形，建议采取一定的温控

Wavefront measurement of double-clad pulsed ytterbium fiber laser

Because of high efficiencies, compact structure, and excellent heat dissipation, high-power fiber lasers are extremely useful for applications such as cutting, welding, precision drilling, trimming, sensing, optical transmitter, material processing, micromachining, and so on. However, the wavefront of the double clad fiber laser doped with ytterbium is still unknown. In this paper, wavefront of a fiber laser is measured and the traditional Hartmann-shack wavefront sensing method is adopted. We measured a double clad fiber laser doped with ytterbium which produces pulse wave output at infrared wavelength. The wavefront shape and contour are reconstructed and the result shows that wavefront is slightly focused and not an ideal plane wavefront. Wavefront measurement of fiber laser will be useful to improving the lasers' performance and developing the coherent technique for its applications.

Finite element analysis on a circular wedge prism with 400 mm diameter

The paper comprehensively analyzes the distortions of a circular wedge prism with 400 mm diameter in a scanner by method of optical-mechanical-thermal integrating analysis. The structure and intensity of the prism assembly is verified and checked, and the surface deformations of the prism under gravity load, as well as the thermo-elastic distortions of the prism, are analyzed in detail and evaluated, which is finally contrasted with the measured values of Zygo Mark interferometer. The results show: the maximal distortion of the prism assembly is 10 nm magnitude and the maximal stress is 0.441 Mpa, which has much tolerance to the precision requirement of structure and the admissible stress of material; the influence of heat effect on the surface deformations of prism is proved to be far greater than the influence of gravity load, so some strict temperature-controlled measures are to be considered when the scanner is used. (c) 2006 Elsevier GmbH. All rights reserved.

基于基频分量消光的1/4波片快轴标定方法

提出了一种基于基频分量消光的波片快轴标定方法,并利用琼斯矩阵对其标定原理进行了分析。激光器、起偏器、相位调制器、待标定1/4波片、检偏器和光电探测器构成标定光路,起偏器、检偏器的透光轴与相位调制器的振动轴分别成+45°和0°夹角。准直激光束依次经过起偏器、相位调制器、待标定1/4波片和检偏器,由光电探测器接收。理论分析表明该标定方法标定精度主要取决于检偏器的定位误差。实验验证了该标定方法的有效性,1/4波片快轴标定结果的最大偏差为0.043°,标准差为0.012°,标定精度为0.05°。

双光栅并联匹配解调技术的工程化研究

在分析和综合其他数据处理方案优缺点的基础上,提出了一种基于分区查表法的有效数据处理方案.该方案先确定待处理的电压商值在三段近似线性曲线上所属区域,再执行查表法将其和微应变量一一对应.这种处理方案不但解决了传统单匹配解调技术中的双值和可测试范围小的问题,而且提高了测试准确度.根据实验结果,采用普通的光纤光栅对,系统可传感的应变范围可达525 με,准确度可达±1 με.

On a fiber grating sensor system with the capacity of cross-sensitivity discrimination

A novel fiber Bragg grating (FBG) sensor system based on an interrogating technique by two parallel matched gratings was designed and theoretically discussed. With an interrogation grating playing the role of temperature compensation grating simultaneously, the wavelength drifts induced by temperature and strain were discriminated. Additionally, the expressions of temperature and strain were deduced for our solution, and dual-value problem and cross sensitivity were solved synchronously through data processing. The influence of the FBG's parameters on the dynamic range and precision was discussed. Besides, the change of environment temperature cannot influence the dynamic range of the sensor system through temperature tuning. The system proposed in this paper will be of great significance to accelerate the real engineering applications of FBG sensing techniques. (c) 2007 Elsevier GmbH. All rights reserved.

A high accuracy image sensor for sinusoidal phase-modulating interferometry

We proposed a high accuracy image sensor technique for sinusoidal phase-modulating interferometer in the field of the surface profile measurements. It solved the problem of the CCD's pixel offset of the same column under two adjacent rows, eliminated the spectral leakage, and reduced the influence of external interference to the measurement accuracy. We measured the surface profile of a glass plate, and its repeatability precision was less than 8 nm and its relative error was 1.15 %. The results show that it can be used to measure surface profile with high accuracy and strong anti-interference ability. (C) 2007 Elsevier GmbH. All rights reserved.

Some engineering issues of an FBG sensor with the dual gratings parallel matched interrogation method

The key issues of engineering application of the dual gratings parallel matched interrogation method are expanding the measurable range, improving the usability, and lowering the cost by adopting a compact and simple setup based on existing conditions and improving the precision of the data-processing scheme. A credible and effective data-processing scheme based on a novel divisional look-up table is proposed based on the advantages of other schemes. Any undetermined data is belonged to a certain section, which can be confirmed at first, then it can be looked up in the table to correspond to microstrain by the scheme. It not only solves inherent problems of the traditional one (double value and small measurable range) but also enhances the precision, which improves the performance of the system. From the experimental results, the measurable range of the system is 525 mu epsilon, and the precision is +/- 1 mu epsilon based on normal matched gratings. The system works in real time, which is competent for most engineering measurement requirements. (C) 2007 Elsevier GmbH. All rights reserved.

溶胶-凝胶多孔二氧化硅减反膜稳定性研究

多孔SiO2膜层经热处理后，具有很高的激光破坏阈值，但是结构中有许多Si-OH亲水基团，导致光学透过率受环境相对湿度的影响很大。实验目的是改善膜层内部结构，使膜层结构中的亲水基团转变为疏水基团。提高膜层的疏水性，增强膜层的透过率稳定性。系统地研究了膜层透过率随时间变化的规律，在氨气和六甲基二硅氮烷(HMDS)混合气氛下热处理膜层，处理后生成Si-O-Si(CH2)3非极性疏水基团，使膜层的疏水性大大提高，因而膜层的透过率稳定性有大幅度提高。稳定性的提高延长了膜层的寿命。处理后膜层的表面粗糙度良好，均方根表