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71.
72.
M. E. Pleydell 《Optics & Laser Technology》1987,19(3)
This note reports a laser Doppler interferometer for measuring the axial motion of solid targets which have had no prior preparation. Both magnitude and sense of motion are measured to a resolution at least 0.316 μm usinga passive optical system and simple signal processing, making the device relatively cheap to construct. Results indicate that the LDI is capable of good linearity over a substantial range of target amplitudes and has a reasonable degree of immunity from speckle effects. 相似文献
73.
We study the role of entanglement and non-locality in quantum protocols that make use of systems of identical particles. Unlike in the case of distinguishable particles, the notions of entanglement and non-locality for systems whose constituents cannot be distinguished and singly addressed are still debated. We clarify why the only approach that avoids incongruities and paradoxes is the one based on the second quantization formalism, whereby it is the entanglement of the modes that can be populated by the particles that really matters and not the particles themselves. Indeed, by means of a metrological and of a teleportation protocol, we show that inconsistencies arise in formulations that force entanglement and non-locality to be properties of the identical particles rather than of the modes they can occupy. The reason resides in the fact that orthogonal modes can always be addressed while identical particles cannot. 相似文献
74.
Electronic-speckle-pattern interferometry and moiré interferometry have been used to calculateK
1 andJ for compact tension specimens. Automated-fringe-pattern analysis enables the full-field of data to be used with the minimum
of operator intervention. Measurements are shown to be accurate to within 10 percent. TheJ-measurement procedure employed could form the basis of an automatic-fault detection system. 相似文献
75.
76.
77.
In this paper, the out-of-plane deformation of silicon surface of Direct Chip Attachment (DCA) assembly, under thermal loading,
was measured in real-time by Twyman/Green interferometry. The contour maps of the out-of-plane displacement fields of silicon
surface under thermal loading and cycling of various temperature were obtained. Experimental results show that the relation
between the out-of-plane displacement and temperature is nonlinear and varies with temperature cycling, due to nonlinear mechanical
behavior of the materials used in electronic packaging. A comparison of the out-of-plane displacement fields of silicon surface
measured by T/G interferometry in real-time and replicating technique of high temperature specimen grating of moire interferometry
was made. 相似文献
78.
79.
G. Mudhana 《Optics Communications》2011,284(12):2854-2858
We report a fiber optic probe suitable for measuring the wavelength dispersion of liquids. The measuring probe is made from an extrinsic fiber-optic cavity formed by a lensed photonic crystal fiber (PCF) and a micro-mirror. The custom-designed lensed PCF plays a dual role of collimator to help realize a long cavity length of the order of millimeters and as an efficient reflector to form the reference beam. The length of the cavity used in the experiment is about 1620 μm. In this article, we present the analytical method of obtaining dispersion of the liquid sample from the spectral interferogram of a single-arm or common path interferometer. Sodium chloride salt solutions with varied concentrations are used as an example to demonstrate the efficacy of the instrument. The index change with concentration is found to be linear at low concentrations and deviates from linearity as it approaches saturation. 相似文献
80.
Nadine Werth Mathias S. Müller Johann Meier Alexander W. Koch 《Optics Communications》2011,284(9):2317-2322
Using Laser-based Speckle-Interferometers, the shape of optically rough surfaces can be measured precisely and contactlessly from variable measuring distances even in regions of difficult access. This work is concerned with the integration of a micromirror array (MMA) into an electronic Speckle-Pattern-Interferometer. With the adaptive optics, it is intended to adapt the phasefront of a reference wave to critical surface areas of the measurement object. Yet, due to the topography of the MMA, diffraction effects occur which affect the phase and intensity of the generated wavefront. We demonstrate how these diffraction effects can be efficiently modelled by a Fraunhofer diffraction method. We compare the results of this model to theoretical data obtained by a numerical Fresnel diffraction model and to measurement data obtained from a measurement setup incorporating a multi mirror array. 相似文献