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Method and device for Doppler laser velocimetry with homodyne detection

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TLDR
In this article, a laser velocimeter with homodyne detection is constructed from a laser 1 whose linearly polarised radiation is applied in 10 to an optical system 2 of the Mach-Zender interferometer type.
Abstract
The laser velocimeter with homodyne detection is constructed from a laser 1 whose linearly polarised radiation is applied in 10 to an optical system 2 of the Mach-Zender interferometer type. The measurement beam strikes the object, whose velocity is to be measured, either directly or through a telescope 8. The signal beam S and the local oscillator beam OL are produced with a slight angular offset between them before striking a double detector 5. The angular offset is chosen so that the wavefronts of the two beams are offset by a half wavelength over the whole surface of the double detector 5. A comparison of the phases of the signals received by the two detectors gives the sign of the velocity.

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Solid-block homodyne interferometer

TL;DR: In this article, a solid-block homodyne Doppler interferometer utilizing continuous-wave or pulse-wave light beam technology was proposed, which eliminates the need for individually supported mirrors and beamsplitters.
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TL;DR: In this article, an all-fiber wind measurement laser radar apparatus based on an asymmetric M-Z interferometer and a method is presented. But, the measurement sensitivity can be raised by reducing the free spectrum spacing of the MZI and the demodulation method of differential intersect multiply by is adopted.
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TL;DR: In this article, an optical system for angular velocity measurement is described, which includes a laser light source, a first beam splitting prism, a polarization beam splitter, a second beamsplitting prism, spiral phase sheet and a quarter wave plate.
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TL;DR: In this article, an angular velocity measurement system consisting of a laser light source, a first beam splitter prism, a polaroid and a photoelectric detector was proposed to adjust the light intensity ratio of signal light to reference light.
References
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Apparatus for measuring velocity by the detection of scattered light

TL;DR: In this article, the velocity of an object through a fluid, e.g. the air, is determined by providing on the object, a light source radiating a beam of light 17 into the fluid and a receiver 15, receiving light 18 scattered from said beam by particles of the fluid, and comprising means determining the Doppler shift in the received light due to the velocity.
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Improvements in or relating to Vibration Responsive Apparatus

TL;DR: In this article, a laser beam is split into two orthogonally polarized beams by prisms 14 having a polarizing dielectric interface and the outputs of the detectors are passed to a differential amplifier whose output comprises a signal representative of the vibrations of the element 10 and modulated at the frequency of the mirror 16.
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Contactless determination of direction of movement - uses two opto-electronic transducers to pick up reflected light, and uses phases of their output signals to determine direction

TL;DR: In this article, the transducers are staggered in the direction of movement, and their output signals (S1, S2) are converted into rectangular signals, which are then compared in a phase comparator and binary signals are delivered, depending on the positive or negative phase shift.
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