干涉数据光谱反演方法研究

干涉光谱仪获取的干涉数据是一种中间数据,需要进行光谱反演,常规的方法是采用傅里叶逆变换反演光谱。文章由干涉数据的基本公式入手,推导出干涉数据的混合模型,给出一种基于干涉数据混合模型的光谱反演方法。利用干涉数据对该方法及傅里叶逆变换方法进行计算机仿真,对其光谱反演结果进行对比。由仿真结果可以看出,所提方法反演的光谱精度要优于通用的傅里叶逆变换方法反演的光谱,为干涉数据光谱反演提供新的思路。     

Asymmetric Fabry-Pérot interferometric cavity for fiber optical sensors

Good linearity and wide dynamic range are the advantages of asymmetric Fabry-Pérot (F-P) interferometric cavity, whose realization has been long for. Based on optical thin film characteristic matrix theory, an asymmetric F-P interferometric cavity with good linearity and wide dynamic range is designed. And by choosing the material of two different thin metallic layers, the asymmetric F-P interferometric cavity is successfully fabricated. The design theory and method of this asymmetric F-P interferometric cavity have been described in detailed. In this paper an asymmetric F-P interferometric cavity used in fiber optical sensor is reported.     

A review on refractive index and temperature profile measurements using laser-based interferometric techniques

In this review we have discussed laser-based interferometric techniques for measurement of refractive index, temperature and temperature profile of burners with special emphasis on laser speckle techniques and Talbot interferometric technique.     

Theoretical analysis of third order interferometric autocorrelation signals for enhanced sensitivity towards pulse chirp and asymmetry

In this paper, we report theoretical analysis of third order interferometric autocorrelation to achieve enhanced sensitivity towards pulse chirp and asymmetry. The analysis is based on interferometric correlative envelope (ICE) functions and ICE difference signals derived from interferometric autocorrelation signals. The third order ICE signals are compared with second order ICE signals obtained from a second order interferometric autocorrelation signals. It is shown that one out of six third order ICED signals may be used to obtain simultaneous detection and measurement of pulse chirp as well as pulse asymmetry of the chirped ultrashort laser pulse. This is in contrast to use of two out of three second order ICED signals for simultaneous detection of pulse chirp and asymmetry.     

干涉光谱图像序列压缩的实验研究

基于均匀值量化压缩算法和AR模型算法,对干涉型超光谱成像仪直接产生的实际干涉图像序列进行了近无损压缩仿真实验.AR模型算法对残差采用Lloyd-Max量化器进行量化,对量化输出结果用Huffman编码器进行编码.分析了AR模型阶数对压缩性能的影响.结果指出,均匀值量化和AR模型算法均能满足干涉光谱图像序列压缩的要求.     

X-ray interferometric Fourier holography

An X-ray interferometric Fourier holography was proposed and theoretically investigated. X-ray Interferometric Young fringes and the reconstruction of an object image were investigated by the Fourier transform method. It was shown that on the output surface of the analyzer crystal (the third plate of the interferometer) the interference pattern of two slits gives X-ray interferometric Young fringes. An expression for the period of X-ray interferometric Young fringes was obtained. The subsequent reconstruction of the slit image as an object is conducted by means of the Fourier transform method of intensity distribution on the hologram. Three methods for reconstruction of the function of complex transmission of the object are presented: an analytical one–the approximate method, the iteration method and the step-by-step approach. As examples a recording of X-ray interferometric Fourier hologram and the reconstruction of the function of complex amplitude transmission of a beryllium circular cylinder are given.     

ATIR proximity sensing through an absorbing medium

In this paper we describe a new simple interferometric method for measurement of the thickness of a very thin quivette filled with absorbing liquid. The method is based on the interferometric restoration and analysis of both p- and s-components of the attenuated totally internal reflected (ATIR) field. Two different liquid samples were studied experimentally. The interferometric signal obtained by measurements is compared with the theoretical prediction.     

低相干光源干涉系统在大口径拼接子镜间相位误差检测上的应用

针对大口径望远镜拼接式主镜,提出一种基于迈克耳孙干涉原理的低相干光源干涉检测系统.应用该系统对拼接子镜间相位失调误差进行实时检测.进而对失调子镜进行相应校正,以实现拼接子镜的共面排布.给出了低相干光源干涉检测系统的具体结构,叙述了干涉检测系统的检测原理,提出应用双中心波长组合低相干光源进行拼接子镜间相位误差检测,分析了系统最低信噪比.结果表明,双中心波长组合低相干光源系统,可以提高低相干光源下涉中心条纹的信号分辨能力.借以提高检测精度.使得低相干光源干涉测量系统对拼接子镜间的相位失调误差进行高精度提取.     

Nulling interferometry for the DARWIN space mission

The DARWIN observatory will include an interferometric instrument dedicated to the search for and spectral analysis of extrasolar planets. This instrument is based on the principle of Bracewell's interferometric coronograph or nulling interferometer, proposed in 1978, but at present never experimentally demonstrated in the thermal infrared with high extinctions.We have shown that high interferometric extinctions can only be obtained with `classical' optical pieces if the beams are cleaned by optical filtering during the recombination. After a short reminder of the nulling interferometer, we present different techniques of optical filtering to perform it. Then, we present a laboratory experimental bench we have constructed, which allows us, at present, to exhibit a monochromatic stable interferometric extinction better than 10³. Finally, we discuss this method, applied to ground-based telescopes.     

星载InSAR基线矢量方位动态测量方法研究

 星载InSAR干涉基线矢量方位角的测量精度对整个系统的测绘精度有着十分重要的影响。针对星载InSAR测量系统对其干涉基线矢量方位角的测量要求,给出了一种基于图像处理的CCD摄像测量方法。利用CCD摄像测量法对主副天线在平面内的相对位移进行了精确测量。分析了系统的理论误差,构建了完整的实验系统,并对光学靶标的固定步长位移进行验证性实验测量,实验结果与理论分析值具有较好的一致性,测量系统的测量精度优于1σ,证明了该测量方法具有很好的可行性。     

光纤干涉成像阵列全息相位校正研究

针对光纤传输和干涉成像阵列中的相位误差, 提出了一种基于特殊光子晶体的全息相位校正方法。首先分析了光纤干涉阵列成像的基本原理和相位信息的传输过程, 以一维线性阵列建立成像系统相位误差模型, 通过对参考光束和探测器前的快门交替打开和闭合, 来分别实现在晶体上写入由光纤阵列的出射光束与参考光束干涉形成的含有相位误差的光栅函数, 和光纤中出射光束被该光栅衍射和相位偏移以消除相位误差, 从理论上分析了上述基于光子晶体的全息法相位校正原理。最后采用所建立的含有相位误差的干涉阵列进行成像仿真, 对未加校正、采用本文方法和采用冗余基线校正的结果进行了对比分析。     

干涉型表面等离激元显微术成像的研究

运用Matlab系统地模拟了信号光相位与样品的厚度和折射率之间的对应关系,为干涉型表面等离激元显微术提供了理论依据,同时证明了基于相位探测的干涉型表面等离激元显微术相比基于强度探测的表面等离激元显微术具有更高的纵向分辨率,而且为生物化学方面的动态变换过程的实时监测提供了一种新方法.     

多道干涉仪测量托卡马克等离子体电子密度

一、引 言 在目前托卡马克等离子体诊断中,采用垂直多道干涉仪测量等离子体电子密度时,由于等离子体水平位移的影响,使得测量信号在沿大环半径方向的分布是非对称的。这就要求采用非对称的Abel变换来给出等离子体电子密度的空间分布。一种常用的非对称Abel变换是分离变量法,它的基本思想是把测量信号分成对称元和非对称的权函数,对称部分采用标准的Abel变换,变换的结果乘上非对称的权函数。这种方法实际上是假定了等离子体电子密度弦积分值的不对称性与局部的不对称性是相同的;而且对称部分采用标准的Abel变换,如Barr的方法,Bockasten方法等。这些方法是把等离子体看成一个个同心圆,没有考虑到等离子体水平位移引起的弦长变化。本文采用一种新的变换方法,这种方法的特点是考虑到等离子体位移的实际情况。     

High sensitivity adaptive optics control of laser beam based on interferometric phase-front detection

We present an upgrade of an adaptive optics (AO) system for the control of geometrical fluctuations in a laser beam, based on the interferometric detection of phase front. Acoustic isolation and suitable design of optical system make the present system very sensitive to laser beam geometrical fluctuations and can be an interesting step toward the active correction of the small perturbations of the input beam of gravitational wave interferometric detectors.     

Interferometric Direction Finding by a Vector-Scalar Receiver

A method for interferometric direction finding of a broadband sound source in an oceanic waveguide by a single vector-scalar receiver is presented. The method is based on the double Fourier transform of the interference pattern formed during motion. The efficiencies of the proposed direction finding method and the method based on measuring the delay times of signals arriving at spaced scalar receivers are compared based on the natural experiment results. The noise immunity of the interferometric direction finding method is considered.     

Gaussian interferometric power and Black box estimation of Unruh temperature

We present a black box estimation paradigm of Unruh temperature in a relativistic bosonic continuous-variable setting. It is shown that the guaranteed precision for the estimation of Unruh temperature can be evaluated by the Gaussian interferometric power for a given probe state. We demonstrate that the amount of interferometric power is always beyond the entanglement type quantum correlations in a relativistic setting. It is found that due to the fact that Unruh radiation acts as a thermal bath on the probe system, it destroys available resources of the probe system and reduces the guaranteed precision of the estimation of Unruh temperature. We also find that the thermal noise induced by Unruh effect will generate interferometric power between accelerated Bob and his auxiliary partner anti-Bob, while it does not generate any correlation between inertial Alice and anti-Bob.     

Spectral interferometry and reflectometry used to measure thin films

A new method for a precise measurement of the oscillatory part of phase change on reflection (interferometric phase) from a thin-film structure is presented. The method, which is based on phase retrieval from the spectral interferograms recorded at the output of a slightly dispersive Michelson interferometer, is combined with reflectometry. The interferometric phase of the thin-film structure is measured precisely using a reference sample of known phase change on reflection. The spectral reflectance of the thin-film structure is also measured in the interferometer. The feasibility of the method is confirmed in processing the experimental data for SiO₂ thin film on a silicon wafer of known optical constants. Four samples of the thin film are used and their thicknesses are determined. We confirm very good agreement between the thicknesses obtained from the interferometric phase and reflectance measurements. PACS  07.60.Ly; 68.55.Jk; 78.20.Bh     

合肥光源上采用干涉方法测量束流截面

 束流截面尺寸测量对优化系统参数、确保光源运行至关重要。采用干涉法测量合肥同步辐射光源束流截面垂直方向的尺寸。基于Cittert-Zernike 定理,利用双缝干涉条纹的对比度得出相干度和束流截面尺寸。测量系统由干涉成像与图像处理系统组成。进行了5组试验,试验结果证明了干涉法测量合肥同步辐射束流截面尺寸的可行性。     

A comparison of interferometric techniques for fiber cladding diameter measurements

Two interferometric techniques have been proposed as reference test methods for fiber cladding diameter measurements. These techniques derive their calibration accuracy from interferometric fundamentals instead of calibration artifacts. Prototypes of these systems are evaluated and contrasted for accuracy, precision, simplicity of construction, cost, and ease of use.     

非球面光学元件的面形检测技术

介绍了非球面各加工阶段的面形检测技术及其最新进展,重点介绍了非球面精密抛光期的面形检测技术,并对其中的非零位子孔径拼接干涉检测法和部分补偿法进行了详细阐述,提出了适用于大口径、深度非球面面形检测的组合干涉法的概念。概述了近年来受到关注的自由曲面非球面的发展和检测技术现状,展望了非球面检测技术的发展趋势。