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Ophthalmic Laser Interferometry
SPIE Proceedings, 1986If the pupil of the eye is illuminated by a collimated laser beam the light returning from the eye exhibits Newton's interference fringes. This phenomenon can be used (1) to measure fundus tissue pulsations and (2) to measure the optical length of the eye.
A F. Fercher, E Roth
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Parallel multiplex laser feedback interferometry
Review of Scientific Instruments, 2013We present a parallel multiplex laser feedback interferometer based on spatial multiplexing which avoids the signal crosstalk in the former feedback interferometer. The interferometer outputs two close parallel laser beams, whose frequencies are shifted by two acousto-optic modulators by 2Ω simultaneously. A static reference mirror is inserted into one
Song, Zhang, Yidong, Tan, Shulian, Zhang
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SPIE Proceedings, 1990
By using a multiphase detection technique, unambiguous shot-noise-limited measurements of unwrapped (i.e. not limited to modulo 21) interferometric phase may be made at data rates in excess of 1 MHz. This technique is ideally suited for use with laser diodes.
Michael Hercher, Geert Wyntjes
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By using a multiphase detection technique, unambiguous shot-noise-limited measurements of unwrapped (i.e. not limited to modulo 21) interferometric phase may be made at data rates in excess of 1 MHz. This technique is ideally suited for use with laser diodes.
Michael Hercher, Geert Wyntjes
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Laser interferometry based seismic sensor
SPIE Proceedings, 2003Laser interferometry is one of the most sensitive and versatile techniques for small relative displacements measurement. For these reasons it is used or it is being introduced in many different fields of research. One of its possible applications is seismic activity monitoring, obtained by fixing the mirrors of an interferometer to the ground. In order
BARONE, Fabrizio +3 more
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Retina, 1999
To determine the functional predictive value of laser interferometry (LI) in retinal detachment (RD).Laser interferometry with test field diameters of 3 degrees and 8 degrees, both with and without light, was tested preoperatively in 42 eyes with rhegmatogenous RD that were candidates for scleral buckling.
M, Roldán-Pallarés +2 more
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To determine the functional predictive value of laser interferometry (LI) in retinal detachment (RD).Laser interferometry with test field diameters of 3 degrees and 8 degrees, both with and without light, was tested preoperatively in 42 eyes with rhegmatogenous RD that were candidates for scleral buckling.
M, Roldán-Pallarés +2 more
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SPIE Proceedings, 1990
A system has been developed which is capable of interferometrically measuring optical path length changes, with high spatial and temporal resolutions. The capability to freeze fast motion is provided by the pulse length of the laser, the frame rate is determined by the laser and camera, and the spatial resolution is determined by the camera and data
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A system has been developed which is capable of interferometrically measuring optical path length changes, with high spatial and temporal resolutions. The capability to freeze fast motion is provided by the pulse length of the laser, the frame rate is determined by the laser and camera, and the spatial resolution is determined by the camera and data
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Imaging focused laser differential interferometry
Optics LettersFocused laser differential interferometry (FLDI) is an important diagnostic for measuring density fluctuations in high-speed flows. Currently, however, high dynamic range FLDI is limited to photodiode measurements. In order to spatially resolve multiple locations within complex flows, we present a novel, to the best of our knowledge, refractive-optic ...
Andrew W. Marsh +3 more
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Pulsed HF Laser Holographic Interferometry
Applied Optics, 1975Two-dimensional holographic interferometry has been accomplished at wavelengths near 3 microm. The source is a pulsed hydrogen fluoride oscillator-amplifier system. Transverse excitation is achieved with a fast bank discharging into a simple electrode configuration.
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Particle sizing using laser interferometry
Applied Optics, 1977The theory and conditions are summarized under which single spherical particles in the size range of a few micrometers and larger may be sized using the observed fringe visibility in a cross-beam laser velocimeter. Scalar diffraction theory and experimental data are presented to show how the size information in the forward- scattered light is dependent
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2004
Publisher Summary This chapter presents a phase-measuring technique in an unbalanced interferometer using direct frequency modulation of laser diodes (LD) sources by changing currents. The wavelength is stepwise, sinusoidally changed to introduce a time-varying phase difference between the two beams of the interferometer.
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Publisher Summary This chapter presents a phase-measuring technique in an unbalanced interferometer using direct frequency modulation of laser diodes (LD) sources by changing currents. The wavelength is stepwise, sinusoidally changed to introduce a time-varying phase difference between the two beams of the interferometer.
openaire +1 more source