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NL6815932A - - Google Patents

Info

Publication number
NL6815932A
NL6815932A NL6815932A NL6815932A NL6815932A NL 6815932 A NL6815932 A NL 6815932A NL 6815932 A NL6815932 A NL 6815932A NL 6815932 A NL6815932 A NL 6815932A NL 6815932 A NL6815932 A NL 6815932A
Authority
NL
Netherlands
Prior art keywords
mirror
interferometer
signal
high frequency
nov
Prior art date
Application number
NL6815932A
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed filed Critical
Publication of NL6815932A publication Critical patent/NL6815932A/xx

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
    • G01B9/02055—Reduction or prevention of errors; Testing; Calibration
    • G01B9/02075—Reduction or prevention of errors; Testing; Calibration of particular errors
    • G01B9/02078—Caused by ambiguity
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B9/00—Measuring instruments characterised by the use of optical techniques
    • G01B9/02—Interferometers
    • G01B9/02055—Reduction or prevention of errors; Testing; Calibration
    • G01B9/02062—Active error reduction, i.e. varying with time
    • G01B9/02067—Active error reduction, i.e. varying with time by electronic control systems, i.e. using feedback acting on optics or light
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04R—LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; DEAF-AID SETS; PUBLIC ADDRESS SYSTEMS
    • H04R23/00—Transducers other than those covered by groups H04R9/00 - H04R21/00
    • H04R23/008—Transducers other than those covered by groups H04R9/00 - H04R21/00 using optical signals for detecting or generating sound
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
    • G01B2290/00—Aspects of interferometers not specifically covered by any group under G01B9/02
    • G01B2290/25—Fabry-Perot in interferometer, e.g. etalon, cavity

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Automation & Control Theory (AREA)
  • Optics & Photonics (AREA)
  • Acoustics & Sound (AREA)
  • Signal Processing (AREA)
  • Mechanical Light Control Or Optical Switches (AREA)
  • Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
  • Lasers (AREA)
  • Instruments For Measurement Of Length By Optical Means (AREA)

Abstract

1,243,359. Light modulators. COMPAGNIE GENERAL D'ELECTRICITE. 8 Nov., 1968 [10 Nov., 1967], No. 53164/68. Heading H4F. [Also in Divisions G1 and G2] Small displacements are detected by coupling them to one mirror of a Fabry-Perot interferometer, detecting the intensity of light passing through or reflected from the interferometer, feeding back a signal to a transducer tending to keep the variations in mirror spacing less than #/4 and using the fed back signal as an indication of the displacements. The interferometer 1, which is illuminated by a He-Ne laser 4, comprises mirrors 8 and 9 coupled to a piezoelectric ceramic or magnetostrictive cylinder 16 rigidly and by a diaphragm 11 respectively. The light intensity emerging at 10<SP>1</SP> or 10<SP>11</SP> is measured by a photo-cell 12 and compared with a reference signal from a photocell 7 and any difference energizes the cylinder 16 to reduce the difference. The laser may be modulated at a high frequency to facilitate amplification, the high frequency signal being filtered out of the feed back loop. Microphones.-Sound vibrations incident upon the mirror 9 produce corresponding signals at the output S. For high frequency response the interferometer is supported at the mirror 8 end and is vented to the atmosphere. For low frequency response, it is supported at the other end; fluid-tight and provided with a smaller aperture diaphragm. The device may be used as an accelerometer by using the mirror 9 or a body attached thereto as seismic mass.
NL6815932A 1967-11-10 1968-11-08 NL6815932A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR127817 1967-11-10

Publications (1)

Publication Number Publication Date
NL6815932A true NL6815932A (en) 1969-05-13

Family

ID=8641565

Family Applications (1)

Application Number Title Priority Date Filing Date
NL6815932A NL6815932A (en) 1967-11-10 1968-11-08

Country Status (5)

Country Link
BE (1) BE722797A (en)
DE (1) DE1807876A1 (en)
FR (1) FR1555697A (en)
GB (1) GB1243359A (en)
NL (1) NL6815932A (en)

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3116346A1 (en) * 1980-05-01 1982-03-04 National Research Development Corp., London DEVICE FOR MEASURING THE SOUND VOLUME OR OF VOLUME FLOW, IN PARTICULAR IN THE LOW AREA OF NANOLITERS PER SECOND
DE3142164A1 (en) * 1980-10-27 1982-06-16 Rosemount Engineering Co. Ltd., Bognor Regis, Sussex DEVICE FOR MEASURING PRESSURE DIFFERENCES
FR2538195B1 (en) * 1982-12-16 1986-10-17 Int Standard Electric Corp OPTICAL TRANSMISSION METHOD AND SYSTEM
JPS61235731A (en) * 1985-04-11 1986-10-21 Sharp Corp Pressure sensing element
JPS6230921A (en) * 1985-07-31 1987-02-09 Sharp Corp Optical sensor
DE3709253A1 (en) * 1987-03-20 1988-09-29 Fraunhofer Ges Forschung Fabry Perot sensor
FR2640456A1 (en) * 1988-12-13 1990-06-15 Science Tec MICROPHONE WITH INTERFEROMETRIC SOUND PRESSURE DETECTION
DE4125485C2 (en) * 1991-08-01 1994-05-19 Deutsche Aerospace Method and arrangement for measuring the smallest deflections
US7583390B2 (en) 2006-03-02 2009-09-01 Symphony Acoustics, Inc. Accelerometer comprising an optically resonant cavity
US7355723B2 (en) * 2006-03-02 2008-04-08 Symphony Acoustics, Inc. Apparatus comprising a high-signal-to-noise displacement sensor and method therefore
CN102833661B (en) * 2012-08-15 2016-08-03 温州泛波激光有限公司 A kind of laser microphone

Also Published As

Publication number Publication date
FR1555697A (en) 1969-01-31
GB1243359A (en) 1971-08-18
DE1807876A1 (en) 1969-07-31
BE722797A (en) 1969-04-24

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