激光干涉仪与纳米精度检测

文章对光外差、移相、正弦相位调制等几种常见的纳米精度干涉测量技术进行了综述 ,并介绍了上海光机所的相关工作 .     

Spin-Dependent Electron Interferometers

We have studied theoretically the interplay between quantum interference and spin-orbit coupling in electron interferometers realized in semiconductor nanostructures. The correlation between spin quantization axis and propagation direction for electrons with fixed energy results in the appearance of spin-dependent interference fringes. We apply the spin-resolved scattering formalism to calculate transport in electronic versions of Youngs double-slit interferometer and the Mach-Zehnder interferometer. The possibility to tune spin-orbit coupling of the Rashba type using external gate voltages makes it possible to use such interferometer setups for magnet-less spintronics and quantum information processing.     

Spin-Dependent Electron Interferometers

We have studied theoretically the interplay between quantum interference and spin-orbit coupling in electron interferometers realized in semiconductor nanostructures. The correlation between spin quantization axis and propagation direction for electrons with fixed energy results in the appearance of spin-dependent interference fringes. We apply the spin-resolved scattering formalism to calculate transport in electronic versions of Youngs double-slit interferometer and the Mach-Zehnder interferometer. The possibility to tune spin-orbit coupling of the Rashba type using external gate voltages makes it possible to use such interferometer setups for magnet-less spintronics and quantum information processing.     

Surfaces of Constant Order for Laterally Spaced Interferometers

The concept of curves and surfaces of constant order, previously considered for parallel-plane interferometers, is here considered for laterally spaced interferometers, such as multiple-slit systems including gratings, under Fraunhofer diffraction conditions. It is also shown to be useful in special cases of Fresnel diffraction.     

Thermopower in Andrew Interferometers

We examine the thermopower Q of a mesoscopic normal-metal (N) wire in contact to superconducting (S) segments and show that even with electron-hole symmetry, Q may become finite due to the presence of supercurrents. Moreover, we show how the dominant part of Q can be directly related to the equilibrium supercurrents in the structure. We also discuss the thermopower arising due to an anomalous kinetic coefficient which is finite in the presence of supercurrent and in some situations gives the dominant contribution. In general, a finite thermopower appears both between the N reservoirs and the superconducters, and between the N reservoirs themselves. The latter, however, strongly depends on the geometrical symmetry of the structure. The paper includes a detailed analytical derivation of the results and an exact numerical solution of the quasiclassical equations in a few sample geometries. PACS numbers: 74.25.Fy, 73.23.-b, 74.45.+c.     

用于原子干涉仪的光学锁相环系统

研制了一种用于原子干涉仪的外差式光学锁相环系统,实现了两台外腔半导体激光器频率和相位的同步,锁相后的激光拍频线宽低于1 Hz,10 MHz积分带宽内的残余相位噪音为0.002 rad2,频偏1~100 kHz范围内的相位噪音达到-100 dBc/Hz。研究了闭环相位噪音对原子干涉仪的影响,当自由演化时间为200 ms、拉曼π脉冲时间为30 μs、单次循环时间为1 s时,锁相后相位噪音对重力测量灵敏度的贡献为10μGal?Hz-1/2     

On Möbius-band Interferometers

A class of two-beam interferometers, insensitive to mirror tilt, is discussed. The mirrors at the ends of each arm of the interferometer are parallel and rigidly connected and these are moved to change the optical path. If the beams in the two arms have a relative twist of 180°, tilt of this pair of mirrors does not change the interference pattern. Polarization effects in such interferometers can be serious; their compensation is discussed.     

A Device for Calibration of Electronic Speckle Pattern Interferometers

Measurement Techniques - A calibration device intended for metrological assurance of instruments used to measure deformations and displacements by methods of electronic speckle interferometry and...     

激光干涉仪测长精度校准方法的研究

本文从激光干涉仪的工作原理出发，对激光干涉仪测长中存在的各种误差源构成进行分析，从而提出了测长精度校准的不同方法特点，通过理论分析和试验总结出测长精度校准的科学合理的方法。     

Multiplexed Fibre-optic Sensors Using Ring Interferometers

Abstract

We describe a number of multiplexing techniques which may be used for fibre-optic sensors in which the sensing element is a ring resonator. The basic optical unit comprises a sensing ring resonator connected to a second interrogating ring resonator of nearly equal length, and illuminated by a source of short coherence length. A number of such units may be combined to form an array, using coherence multiplexing techniques. Using such an arrangement, the high finesse of the ring resonator may be exploited to yield a sensor of increased sensitivity over that obtainable with a two-beam interferometer. When a high-coherence source is used, then multiplexing may be accomplished using frequency-division techniques. However, in this case, the resonators must have low finesse, in order to avoid cross-talk. We also show that when a source of moderate coherence length is used, it is possible to use both frequency division and coherence multiplexing simultaneously, with the potential of realizing a large sensor array.     

The Fano Effect in Aharonov-Bohm Interferometers

After briefly reviewing the Fano effect, we explain why it may be relevant to various types of Aharonov–Bohm interferometers. We discuss both closed (electron conserving) and open interferometers, in which one path contains either a simple quantum dot or a decorated quantum dot (with more than one internal state or a parallel path. The possible relevance to some hitherto unexplained experimental features is also discussed.     

Optical Synthetic Aperture Analogues of Two Radio Interferometers

Experimental and theoretical results are given for the one and two-dimensional Covington-Drane optical synthetic apertures and the thin annular aperture. The segmented thin annulus is also discussed as a special case of the thin continuous annulus. Experiments are performed by masking a diffraction-limited lens with the appropriate pupil function and then measuring the imaging characteristics of the aperture. All the synthetic apertures are shown to have the full synthetic MTF's predicted by the theory. The Covington-Drane doubles the resolution of the central aperture and the thin annular apertures synthesize the full lens spatial frequency response. Optical processing of synthetic aperture photography is discussed and examples of inverse spatial filters are given.     

Response of Fabry-Perot Interferometers to Amplitude-modulated Light Beams

The response of a Fabry-Perot interferometer to amplitude-modulated light beams is studied through invariant linear system theory. Different approaches operating in the time or in the frequency domain are compared. Some particular cases of practical importance are treated in detail.     

外差激光干涉仪非线性的细分和消除

通过理论推导得到一个消除外差激光干涉仪非线性的理论,只要改变干涉仪的结构,也就是增加光程倍数,就可以减小激光干涉仪的非线性误差。实验证明,这个方法可以有效地减小双频激光干涉仪的各种非线性误差,不论这个误差是一阶的还是二阶的,也不论是什么原因引起的。它不仅适应于科学实验研究,而且也适应于工业精密测量应用,对纳米测试技术的发展具有实际意义。     

微型激光干涉仪应用于纳米测量机

本文介绍德国SIOS公司的微型激光干涉仪在德国Ilmenau技术大学纳米测量机 (NMM )研制过程中的应用。简要介绍微型激光干涉仪的工作原理 ,重点论述NMM如何在 2 5mmx 2 5mmx 5mm的空间范围内实现分辨力为 1.2nm的三维测量     

Fabry-Perot Interferometers at 168 Gc/s

Extension of high Q resonant devices, such as microwave cavities, into the millimeter region, leads to prohibitively small structures at frequencies above 100 Gc/s. The Fabry-Perot interferometer [1]-[3] serves as a satisfactory high Q millimeter resonator, however, since the size of the structure is relatively large compared to a wavelength. This size may be determined in part by external requirements. This paper presents the results of experiments on several different types of interferometers.