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US5825465A Expired / Lapsed US ⏱️ 0.0 years remaining

Autodyne detection laser velocimeter

Assignee: Commissariat à l'Énergie Atomique et Aux Énergies Alternatives
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Filing: 1997-07-17
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Granted: 1998-10-20
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Expires: 2017-07-17
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Abstract

Abstract Autodyne laser velocimeter comprising: a microlaser (10) capable of emitting respectively a first (40) and second (42) beam, pumping means (12) capable of supplying a pumping beam light to the microlaser, optical means (14) capable of directing the first beam (40) at a target (50) and of sending the light re-emitted by the target (50) to the microlaser (10), photoelectric detection means (16) of receiving the second beam and emitting a detection signal corresponding to a modulation in the intensity of the second beam, and means (17) of processing the detection signal to determine a characteristic magnitude of a displacement velocity of the target. Application to metrology.

Inventors

  • 👤 Philippe Nerin
  • 👤 Pascal Besesty
  • 👤 Herve Giraud
  • 👤 Andre Mouttet

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 20:21
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/36; G01P3/366; G01P5/00; G01P5/26; G01S; G01S17/00; G01S17/02; G01S17/50; G01S17/58; G01S7/00; G01S7/48; G01S7/491; G01S7/4912; G01S7/4916; H; H01; H01S; H01S3/00; H01S3/05; H01S3/06; H01S3/0602; H01S3/0604; H01S3/0627

Claims Analysis

Total Claims: 18
Claim 1
Independent Claim 127 words
Autodyne detection laser velocimeter comprising: a microlaser (10) comprising facing first (20) and second (22) emission surfaces capable of emitting respectively a first (40) and second (42) beam from the first and second surfaces (20, 22) respectively, the second emission surface having a lower transmission coefficient than that of the first surface, pumping means (12) capable of supplying a pumping beam to the microlaser, optical means (14) capable of sending the first beam (40) to a target (50) and of directing the light re-emitted by the target (50) to the microlaser (10), photoelectric detection means (16) for receiving the second beam (42) and emitting a detection signal, and means (17) for processing the detection signal to establish a magnitude characteristic of a displacement velocity of the target.
Claim 2
Dependent Claim 127 words
Autodyne detection laser velocimeter comprising: a microlaser (10) comprising facing first (20) and second (22) emission surfaces capable of emitting respectively a first (40) and second (42) beam from the first and second surfaces (20, 22) respectively, the second emission surface having a lower transmission coefficient than that of the first surface, pumping means (12) capable of supplying a pumping beam to the microlaser, optical means (14) capable of sending the first beam (40) to a target (50) and of directing the light re-emitted by the target (50) to the microlaser (10), photoelectric detection means (16) for receiving the second beam (42) and emitting a detection signal, and means (17) for processing the detection signal to establish a magnitude characteristic of a displacement velocity of the target.
Claim 3
Dependent Claim 47 words
Velocimeter of claim 1 wherein the processing means are capable of determining the Doppler frequency characteristic of the displacement of the target and of calculating a magnitude chosen from among a vibration frequency of the target, a displacement of the target and a velocity of the target.
Claim 4
Dependent Claim 44 words
Velocimeter of claim 1 fitted with a microlaser (10) capable of emitting light beams comprising respectively two waves electromagnetically polarized linearly and orthogonally and also comprising an analyzer (62) disposed on one optical path of the second beam (42) targeted at the detection means.
Claim 5
Dependent Claim 24 words
Laser velocimeter of claim 3 wherein the microlaser (10) comprises an amplifying material (18) that is intrinsically birefringent for emitting said two electromagnetic waves.
Claim 6
Dependent Claim 21 words
Laser velocimeter of claim 3 wherein the amplifying material (18) is an intrinsically birefringent crystal split along a plane C (C-cut).
Claim 7
Dependent Claim 25 words
Laser velocimeter of claim 5 wherein the crystal is chosen from among the following: YVO 4 , YLiF 4 and LaMgAl 11 O 9 .
Claim 8
Dependent Claim 21 words
Laser velocimeter of claim 4 wherein the amplifying material (18) is a crystal that has been subjected to stress during growth.
Claim 9
Dependent Claim 23 words
Laser velocimeter of claim 3 wherein the microlaser comprises an amplifying material (18) subject to stress perpendicular to the first and second beams.
Claim 10
Dependent Claim 31 words
Laser velocimeter of claim 1 wherein the pumping means (12) comprise a pumping beam source (30) and an optical system (32, 32b, 34) that focuses the pumping beam onto the microlaser.
Claim 11
Dependent Claim 19 words
Laser velocimeter of claim 9 wherein the optical system of the pumping means comprises a pumping optical fiber (32b).
Claim 12
Dependent Claim 27 words
Velocimeter of claim 10 comprising an optical measuring fiber 62b connected to photoelectric detection means and coupled to pumping optical fiber (32b) by an optical coupler (60b).
Claim 13
Dependent Claim 38 words
Laser velocimeter of claim 1 wherein microlaser (10) comprises an active medium consisting of an amplifying material (18) and two mirrors (20, 22) that respectively constitute the first and second emission surfaces and also constitute an optical resonator.
Claim 14
Dependent Claim 44 words
Laser velocimeter of claim 1 wherein optical means (14) comprise a lens (44) with a focal length (F), said lens being disposed in front of first surface (20) at a distance from said surface that is more or less equal to focal length (F).
Claim 15
Dependent Claim 14 words
Laser velocimeter of claim 1 wherein photoelectric detection means (16) comprise a PIN-type photodiode.
Claim 16
Dependent Claim 18 words
Laser velocimeter of claim 1 wherein the means of processing the detection signal (17) comprise a radiofrequency analyzer.
Claim 17
Dependent Claim 60 words
Velocimeter of claim 1 comprising a section (60) that is more or less transparent at the wavelength of the pumping means (12) but reflects the second beam (42) emitted by microlaser (10), said section being disposed between the pumping beam source (30) and the second surface (22) of microlaser (10) to deflect the second beam (42) onto detection means (16).
Claim 18
Dependent Claim 56 words
Velocimeter of claim 1 comprising a section (60a) that is more or less transparent at the wavelength of the pumping means (12) but reflects the first beam (40) emitted by microlaser (10), said section being disposed between the pumping beam source and the first surface of the microlaser to deflect the first beam onto the target.

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