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US5172185A Expired / Lapsed US ⏱️ 0.0 years remaining

Device for determining or stabilizing the wavelength of laser light in a gaseous ambient medium

Assignee: Dr Johannes Heidenhain GmbH
•
Filing: 1990-04-06
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Granted: 1992-12-15
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Expires: 2010-04-06
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Abstract

Abstract Device for stabilizing the wavelength in air of a laser diode for an Interferometer which measures length in waveguide technology. To stablize the wavelength in air, an interference phenomenon, according to Young, is produced and detected in an air chamber of constant and stable length with two point-shaped light waves of a coherent beam. The point-shaped light waves are formed by the ends of waveguides. The photo-detectors and the control device control the frequency of the laser diode so that the interference phenomenon, and therefore the wavelength in air, remain stable inside the reference chamber. The arrangement is simple and compact.

Inventors

  • 👤 Gerhard Leuchs
  • 👤 Martin Kerner

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-31 17:27
CPC Classifications
H; H01; H01S; H01S5/00; H01S5/06; H01S5/068; H01S5/0683; H01S5/0687; G; G01; G01B; G01B9/00; G01B9/02; G01B9/02049; G01B9/02051; G01B9/02055; G01B9/0207; G01B2290/00; G01B2290/60; G01J; G01J9/00; G01J9/02; G01J9/0246

Claims Analysis

Total Claims: 30
Claim 1
Independent Claim 158 words
A device for determining the wavelength of coherent light from a laser light source found in a preferably gaseous ambient medium, with at least one photo-detector unit to detect interference generated by light from the laser light source in the ambient medium, wherein light stemming from the laser light source is led to and emanates from two spaced locations, which basically constitute point laser light sources, into the ambient medium and that the light waves emitted by the basically point light sources interfere in the ambient medium forming spatial interference detected by one or more photo-detector units, wherein light coming from the laser light source is guided in at least two light waveguides, whose ends leading into the ambient medium are spaced apart and form basically point light sources, and wherein the light waveguides are waveguide paths integrated in a carrier substrate, which end at spaced points at the edge of the carrier adjacent to the ambient medium.
Claim 2
Independent Claim 158 words
A device for determining the wavelength of coherent light from a laser light source found in a preferably gaseous ambient medium, with at least one photo-detector unit to detect interference generated by light from the laser light source in the ambient medium, wherein light stemming from the laser light source is led to and emanates from two spaced locations, which basically constitute point laser light sources, into the ambient medium and that the light waves emitted by the basically point light sources interfere in the ambient medium forming spatial interference detected by one or more photo-detector units, wherein light coming from the laser light source is guided in at least two light waveguides, whose ends leading into the ambient medium are spaced apart and form basically point light sources, and wherein the light waveguides are waveguide paths integrated in a carrier substrate, which end at spaced points at the edge of the carrier adjacent to the ambient medium.
Claim 3
Dependent Claim 21 words
A device according to claim 1, wherein the waveguide reach the edge of the carrier at an angle different from 90°.
Claim 4
Dependent Claim 26 words
A device according to claim 1, wherein the ends of the waveguide paths lie in a plane with the surface of the edge of the carrier.
Claim 5
Dependent Claim 15 words
A device according to claim 1, wherein the laser light source is a laser diode.
Claim 6
Dependent Claim 37 words
A device according to claim 1, wherein the interference is reflected back to the point light sources by using a mirror, and the one or more photo-detector unit lie side by side with the point light source.
Claim 7
Dependent Claim 20 words
An interferometer for length measurement with a device for detecting the wavelength is a gaseous medium according to claim 1.
Claim 8
Dependent Claim 69 words
An interferometer according to claim 6, wherein laser light from the laser light source led over a constant reference distance and over a changing measuring distance and that light from the same laser light source is led in waveguides and emanates from these light waveguides at two spaced locations basically representing two point light sources generating a spatial interference pattern, which is detected by at least one measuring photo-detector.
Claim 9
Independent Claim 155 words
A device for stabilizing the wavelength of coherent light from a laser light source found in a preferably gaseous ambient medium, with at least one photo-detector unit to detect interference generated by light form the laser light source in the ambient medium, wherein light stemming from the laser light source is led to and emanates from two spaced locations, which basically constitute point laser light sources, into the ambient medium and that the light waves emitted by the basically point light sources interfere in the ambient medium forming spatial interference detected by one or more photo-detector units wherein characterized by the fact that it includes an electronic control device which is connected to the one or more photo-detector unit and changes the frequency of the laser light source when there are variations in the refractive index of the ambient medium so that the spatial interference and thus the wavelength in the ambient medium remain constant.
Claim 10
Independent Claim 155 words
A device for stabilizing the wavelength of coherent light from a laser light source found in a preferably gaseous ambient medium, with at least one photo-detector unit to detect interference generated by light form the laser light source in the ambient medium, wherein light stemming from the laser light source is led to and emanates from two spaced locations, which basically constitute point laser light sources, into the ambient medium and that the light waves emitted by the basically point light sources interfere in the ambient medium forming spatial interference detected by one or more photo-detector units wherein characterized by the fact that it includes an electronic control device which is connected to the one or more photo-detector unit and changes the frequency of the laser light source when there are variations in the refractive index of the ambient medium so that the spatial interference and thus the wavelength in the ambient medium remain constant.
Claim 11
Dependent Claim 38 words
A device according to claim 8, wherein light coming from the laser light source is guided in at least two light waveguides, whose ends leading into the ambient medium are spaced apart and form basically point light source.
Claim 12
Dependent Claim 33 words
A device according to claim 9, wherein the light waveguides are waveguide paths integrated in a carrier, which end at spaced points at the edge of the carrier adjacent to the ambient medium.
Claim 13
Dependent Claim 22 words
A device according to claim 10, wherein the waveguide paths reach the edge of the carrier at an angle different from 90°.
Claim 14
Dependent Claim 26 words
A device according to claim 10, wherein the ends of the waveguide paths lie in a plane with the surface of the edge of the carrier.
Claim 15
Dependent Claim 14 words
A device according to claim 12, wherein the spacer is connected to the carrier.
Claim 16
Dependent Claim 33 words
A device according to claim 9, wherein the light waveguides are flexible optical fibers which are spatially held by a holder or the like, at lesat at the ends facing the ambient medium.
Claim 17
Dependent Claim 23 words
A device according to claim 14, wherein the spacer is connected to the holder or is built in a one-piece unit with it.
Claim 18
Dependent Claim 38 words
A device according to claim 8, wherein one or more photo-detector units are attached to a spacer, which is used to keep a constant distance between the basically point light sources and the one or more photo-detector units.
Claim 19
Dependent Claim 31 words
A device according to claim 16, wherein the spacer, which is ring-shaped, encloses a space in which the interference and which communicates with the surrounding air through openings in the spacer.
Claim 20
Dependent Claim 25 words
A device according to claim 16, wherein the spacer is made of material with a thermal coefficient of expansion below 10 -6 K -1 .
Claim 21
Dependent Claim 15 words
A device according to claim 8, wherein the laser light source is a laser diode.
Claim 22
Dependent Claim 37 words
A device according to claim 8, wherein the interference is reflected back to the point light sources by using a mirror, and the one or more photo-detector units lie side by side with the point light source.
Claim 23
Dependent Claim 20 words
An interferometer for length measurement with a device for stabilizing the wavelengths in a gaseous medium according to claim 8.
Claim 24
Dependent Claim 69 words
An interferometer according to claim 21, wherein laser light from the laser light source led over a constant reference distance and over a changing measuring distance and that light from the same laser light source is led in waveguides and emanates from these light waveguides at two spaced locations basically representing two point light sources generating a spatial interference pattern, which is detected by at least one measuring photo-detector.
Claim 25
Independent Claim 129 words
A device for determining the wavelength of coherent light from a laser light source found in a preferably gaseous ambient medium, with at lesat one photo-detector unit to detect interference generated by light from the laser light source in the ambient medium, wherein light stemming from the laser light source is led to and emanates from two spaced locations, which basically constitute point laser light sources, into the ambient medium and that the light waves emitted by the basically point light sources interfere in the ambient medium forming spatial interference detected by one or more photo-detector units, wherein one or more photodetector units are attached to a spacer, which is used to keep a constant distance between the basically point light source and the one or more photo-detector units.
Claim 26
Independent Claim 129 words
A device for determining the wavelength of coherent light from a laser light source found in a preferably gaseous ambient medium, with at lesat one photo-detector unit to detect interference generated by light from the laser light source in the ambient medium, wherein light stemming from the laser light source is led to and emanates from two spaced locations, which basically constitute point laser light sources, into the ambient medium and that the light waves emitted by the basically point light sources interfere in the ambient medium forming spatial interference detected by one or more photo-detector units, wherein one or more photodetector units are attached to a spacer, which is used to keep a constant distance between the basically point light source and the one or more photo-detector units.
Claim 27
Dependent Claim 51 words
A device according to claim 23, wherein the light waveguides are flexible optical fibers, which are spatially held by a holder or the like, at lesat at the ends facing the ambient medium, and wherein the spacer is connected to the holder or is built in a one-piece unit with it.
Claim 28
Dependent Claim 14 words
A device according to claim 23, wherein the spacer is connected to the carrier.
Claim 29
Dependent Claim 33 words
A device according to claim 23, wherein the spacer, which is ring shaped, encloses a space in which the interference occurs and which communicates with the surrounding air through openings in the spacer.
Claim 30
Dependent Claim 26 words
A device according to claim 23, wherein the spacer is made of a material with a thermal coefficient of expansion below 10 -6 K -1 .

References Cited (Backward Citations)

US4668093A Cited
US4722603A Cited
US4747688A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1995-12-15 1996-06-15 1996-12-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1999-12-15 2000-06-15 2000-12-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2003-12-15 2004-06-15 2004-12-15 $7700.00 Window Closed / Lapsed

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