Polarization phase-shifting Jamin shearing interferometer

The Jamin shearing interferometer is very useful in wavefront testing, especially for the low coherent light. Based on this interferometer, a polarization phase-shifting Jamin shearing interferometer is proposed to improve the performance. In the interferometer, two interference beams are linearly polarized and a polarization phase shifter is applied to realize the phase shifting. Different types of configurations of the interferometer are given. With phase-shifting interferograms, the precision of the interferometer can be improved. The interferometer is kept as an equal optical path system and its shearing amount remains changeable with simple structure and easy operation. In experiments, phase-shifting interferograms are obtained by rotating the analyzer. The usefulness of the interferometer is verified.     

一种提高静态傅里叶干涉仪光谱分辨率的方法

为了在不改变静态傅里叶变换干涉具尺寸的前提下提高光谱分辨率,设计了正交斜楔型静态傅里叶变换干涉具,采用两个正交的等效斜楔形成连续的光程差变化.通过推导传统干涉具与正交斜楔型干涉具的光程差函数,设计了采用正交斜楔型干涉具增加有效探测长度,从而提高光谱分辨率的方法.经仿真计算,正交斜楔型干涉具的最大光程差为0.323 4 mm,比传统干涉具的0.080 8 mm大4倍左右,即光谱分辨率提高了4倍.实验证明,由于正交斜楔的探测原理使干涉具边缘的干涉条纹产生畸变,故要对干涉条纹进行边缘切除及滤波,给出了切除大小的计算公式.采用WQF520型光谱仪进行对比实验,检测800 nm的激光,该干涉具误差小于1 nm.该方法可有效地提高静态傅里叶变换干涉具的光谱分辨率.     

高速转镜干涉成像光谱仪

介绍一种高速转镜干涉光谱仪原理,提出一种基于该原理的干涉成像光谱仪,该成像光谱仪有较大视场角,提高了扫描效率,特点是用带有倾角平面反射镜转动代替传统Michelson干涉成像光谱仪动镜的直线运动,解决了Michelson干涉成像光谱仪扫描效率低和不稳定的难题.     

A displacement measurement system, utilizing a Wollaston interferometer

A dual interferometric displacement measurement system is presented where a Wollaston prism interferometer is employed in conjunction with a normal Michelson interferometer. The system operates without the use of external polarizers, apart from those associated with the Wollaston prism interferometer itself. It is shown that an optical path difference induced in the Michelson interferometer can be detected using the Wollaston prism in a normal interferometer arrangement. Further, the interference pattern produced by the Wollaston prism interferometer changes in a measurable, linear fashion as the optical path difference from the Michelson interferometer alters. A simple theoretical analysis of the system is presented and used to derive a computer model of the optical arrangement. Results from an experimental implementation of the system, using a Wollaston prism with a beam separation of 0.5 degrees and a superluminescent diode, of wavelength 825 nm, as a light source, are included and compared to the results from the computer model.     

New large-aperture and high- accuracy lateral shearing interferometer

The principle of a new large-aperture high-accuracy interferometer for flow visualization is presented. The interferometer uses a Twyman-Green interferometer as a beam-splitter, a grating as a detector, and a real-time moiré fringe method to eliminate systematic errors. The interferometer has been used to measure the flow fields in a shock tunnel and obtained satisfactory results.     

Construction and operation of a simple electronic speckle pattern interferometer and its use in measuring microscopic deformations

The construction and operation of a simple electronic speckle pattern interferometer (ESPI) is described. The underlying theory behind the operation of the interferometer, which is sensitive to out-of-plane displacements, is given. The interferometer uses a commercial digital still camera for image acquisition and a personal computer for image storage and analysis. The interferometer was used to measure microscopic deformations of a steel plate caused by small loads. The results were found to be in good agreement with the predictions of the elastic theory. Various possible applications of the interferometer are mentioned.     

便携式泰曼格林型干涉仪装调方法研究

 为满足光学系统对高精度检测的要求,依据一种新型便携式干涉仪的设计方案,研究了装调方法。该型干涉仪基于改进的泰曼-格林光路结构,其设计测试精度达到λ/10（P-V,λ=630 nm）,具有参考镜离轴、体积小巧、便携、精度较高、成本低及便于批量装备等新特点。针对该新型干涉仪的结构特点,研究了以两个互相垂直的光轴为基准对整体结构进行装调的新方法,并用装调完善的干涉仪进行了实测试验和比对试验。试验结果表明,该新型干涉仪器对已知面型精度为λ/10（P-V,λ=630 nm）的标准球面镜进行检测,其精度可达到0.09 λ;在相同的测试条件下进行比对实验时,该新型干涉仪对普通标准球面镜的检测结果为0.053 λ（RMS,λ=630 nm）,ZYGO干涉仪的检测结果为0.051 λ（RMS,λ=632.8 nm）,两者测量能力较为接近。采用新装调方法进行装调的该新型便携式干涉仪的实际检测精度达到了设计要求,新装调方法可以满足该新型干涉仪的指标要求。     

高灵敏度的量子迈克耳孙干涉仪

迈克耳孙干涉仪不仅可以用来研究物理学的基本问题,而且能够用于精密测量,比如引力波信号的测量.因此,构建高灵敏度的迈克耳孙干涉仪是实现微弱信号测量的关键.目前,人们利用压缩态可以降低迈克耳孙干涉仪的噪声;通过光学四波混频过程能够放大马赫·曾德尔干涉仪中的相位信号,从而提高干涉仪的信噪比和灵敏度.本文研究了一种用于高灵敏度相位测量的量子迈克耳孙干涉仪.在迈克耳孙干涉仪中,利用非简并光学参量放大器取代干涉仪中的线性光学分束器;并且将压缩态注入干涉仪的真空通道,可以得到高信噪比和高灵敏度的干涉仪.由于存在不可避免的光学损耗,分析了迈克耳孙干涉仪内部和外部的损耗对相位测量灵敏度的影响.通过理论计算研究了干涉仪的相位测量灵敏度随系统参数的变化关系,得到了高灵敏度的相位测量量子迈克耳孙干涉仪的实现条件,为用于精密测量的干涉仪的设计提供了直接参考.     

光纤连接器端面几何参量自动测量仪

报道了一种高精度测量光纤连接器端面几何参量的自动测量仪。叙述了光纤连接器的端面几何参量的测量原理。由光纤连接器端面形貌和纤芯中心坐标,可以高精度得到曲率半径、顶点偏移量、端面倾斜角和光纤高度等影响连接器性能的关键端面几何参量。该仪器体积小,自动化程度高,用户界面友好,使用方便,可测量物理接触、角度式物理接触等类型的光纤连接器端面几何参量。实际测量证明,该测量仪有很好的重复测量精度。该测量仪与美国Dorc公司ZX-1 mini PMS测量仪和Norland公司NC3000测量仪相比,测量精度水平相当。该仪器样机已通过华东国家计量测试中心的测试。     

Passively stabilized single-photon interferometer

A single-photon interferometer is a fundamental element in quantum information science. In most previously reported works, single-photon interferometers use an active feedback locking system to stabilize the relative phase between two arms of the interferometer. Here, we use a pair of beam displacers to construct a passively stable single-photon interferometer. The relative phase stabilization between the two arms is achieved by stabilizing the temperature of the beam displacers. A purely polarized single-photon-level pulse is directed into the interferometer input port. By analyzing and measuring the polarization states of the single-photon pulse at the output port, the achieved polarization fidelity of the interferometer is about 99.1 ±0.1%. Our passively stabilized single-photon interferometer provides a key element for generating high-fidelity entanglement between a photon and atomic memory.     

Compact cyclic shearing interferometer: part two

A solid cyclic lateral shearing interferometer to be used with parallel beams of light for testing lenses is described. The interferometer can be modified into a polarization interferometer to be used in OTF measurement. The interferometer is compact and immune to environmental disturbance and less prone to misalignment.     

Mach–Zehnder interferometer with squeezed and EPR entangled optical fields

We study a scheme for Mach-Zehnder(MZ) interferometer as a quantum linear device by injecting two-mode squeezed input states into two ports of interferometer.Two-mode squeezed states can be changed into two types of inputs for MZ interferometer:two squeezed states and Einstein-Podolsky-Rosen(EPR) entangled states.The interference patterns of the MZ interferometer vary periodically as the relative phase of the two arms of the interferometer is scanned,and are measured by the balanced homodyne detection system.Our experiments show that there are different interference patterns and periodicity of the output quantum states for two cases which depend on the relative phase of input optical fields.Since MZ interferometer can be used to realize some quantum operations,this work will have the important applications in quantum information and metrology.     

Analysis of period and visibility of dual phase grating interferometer

Dual phase grating interferometer may simultaneously achieve large field of view and high x-ray dose efficiency. Here, we develop a simple theoretical method to better understand the imaging process of the dual phase grating interferometer. The derivation process of fringe period and the optimal visibility conditions of the dual phase grating interferometer are given in detail. Then, we theoretically prove that the fringe period and optimal visibility conditions of the dual phase grating interferometer include that of the Talbot interferometer. By comparing our experimental results with those of other researchers, we find that when the positions of phase gratings are far away from the positions where the fringe visibility is optimal, the fringe period of the dual π -phase grating interferometer is twice the theoretical results under the illumination of polychromatic x-ray. This conclusion may explain the contradictory research results of dual phase grating interferometer among different researchers.     

Linearization and minimization of cyclic error with heterodyne laser interferometry

We present a method for the linearization and minimization of interferometer cyclic error. We utilize a polynomial curve fitting and resampling algorithm to correct for nonlinear mirror displacement. In the frequency domain, this algorithm compresses cyclic error into a single-frequency component and enables the precise measurement of cyclic error in a noise-dominated environment. We have applied the technique to determine the cyclic error for a range of interferometer components. In addition, we have used these measurements to optimize interferometer configuration and performance such that we routinely achieve a cyclic error of ～50 pm for our custom Glan-Laser interferometer and ～100 pm for a commercial interferometer.     

Compulsorily Phase Locked Interferometer Using Orthogonally Polarized Light Source of a Modulated LD with High Extinction Ratio

This paper describes a compulsorily phase locked differential interferometer using an orthogonally polarized light source of a modulated LD with high extinction ratio to reduce non-linearity of the interferometer caused by polarization cross-talk. The current modulated LD is used as a light source to make the interferometer compact and for the scanning phase of the interferometer. The interferometer is operated compulsorily at the maximum inclination point of the fringe intensity curve by fringe scanning and an electric system. A Wollaston prism of high extinction ratio (50 dB) is used to combine the polarizing beams and to make the polarization cross-talk very small. In one light source the polarized output beams are on the same propagation axis; in the other they have a small crossing angle (2.5 mrad ∼ 10 mrad) to completely exclude non-linearity of the interferometer causded by polarization cross-talk. Using jets of a gas mixture of nitrogen and ethylene, this interferometer was demonstrated to be useful in detecting the photothermal effect of a photothermal velocimeter under phase fluctuation in a turbulent flow.     

复合材料分层检测用光纤Mach-Zehnder干涉仪

发展了一种能够有效检测复合材料分层的光纤Mach Zehnder干涉仪。用一只2×2耦合器和一只3×3耦合器构成光纤干涉仪,输出信号经A/D转换后送入计算机,用软件进行信号解调。将此干涉仪的一个臂埋入材料内部或粘贴在复合材料表面,沿光纤逐点下压材料,通过光纤干涉仪测量出传感光纤形变的大小和方向,这样就能够有效的检测出材料内部是否存在分层。     

Knife-edge diffraction pattern as an interference phenomenon: An experimental reality

This paper demonstrates that a knife-edge diffraction pattern is, indeed, due to the interference of two superimposing waves: the geometrical wave and the boundary diffraction wave. Within the framework of boundary diffraction wave theory it is shown that this diffraction pattern can easily be broadened in such a manner that a single fringe covers the whole field of view. At this point the system converges to a schlieren diffraction interferometer and could be used for the study of phase objects using diffraction-limited optics. Experimental observations show that the method bears a similarity to that of any known two-beam interferometer, e.g. Mach-Zehnder interferometer. The experimental details have been presented and the results are compared with a two-beam holographic interferometer and a point diffraction interferometer.     

Zone-Plate Interferometer for Measuring the Shape Error of Mirrors with Large Numerical Aperture and Steep Asphericity

A compact zone-plate interferometer is developed to measure the shape error of concave mirrors. A diffracted light of (0, 0) and that of (-1, -1) or (+1, +1) are used in the interferometer. The interferometer enables us to measure the shape error of mirrors with a large numerical aperture and a steep asphericity. The shape errors of a spherical mirror and a parabolic mirror are measured by the interferometer, and that of the former agrees well with that measured by Fizeau interferometer. Methods for adjustments of zone plates and the mirrors being tested are proposed to perform precise measurements of the mirror shapes.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994.     

克服光纤Mach-Zehnder干涉仪信号衰落的新方法及分析

为了克服光纤Mach-Zehnder干涉仪易受环境因素影响而引起偏置相位漂移从而导致输出信号衰落(波动)的问题,提出一种新的简单方法,即:将干涉仪输出信号分为直流和交流两个分量,通过直流分量的大小来计算交流信号的补偿因子,以达到克服交流信号衰落、稳定检测传感信号的目的在小信号测量情况下,该方法在很大范围内能有效抑制随机温度涨落等因素引起的信号衰落的问题文中对补偿方法的误差和局限性也做了分析和讨论.     

Differential-phase-shift quantum key distribution experiment with a planar light-wave circuit Mach-Zehnder interferometer

A differential-phase-shift quantum key distribution experiment was carried out with a planar light-wave circuit (PLC) Mach-Zehnder interferometer. This scheme has two advantages: it requires no polarization control and has a high repetition frequency, provided that a stable interferometer is available. Stable polarization-insensitive operation was achieved with an interferometer fabricated by PLC technology. Raw key creation at a rate of 3076 bits/s with a 5.0% quantum bit-error rate was achieved over 20 km of fiber. The stability of the PLC interferometer was examined.