JPS57158503A - Measuring method of electric length of optical fiber - Google Patents

Measuring method of electric length of optical fiber

Info

Publication number
JPS57158503A
JPS57158503A JP4433481A JP4433481A JPS57158503A JP S57158503 A JPS57158503 A JP S57158503A JP 4433481 A JP4433481 A JP 4433481A JP 4433481 A JP4433481 A JP 4433481A JP S57158503 A JPS57158503 A JP S57158503A
Authority
JP
Japan
Prior art keywords
fiber
optical fiber
frequency
phase difference
signal
Prior art date
Legal status (The legal status 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 status listed.)
Pending
Application number
JP4433481A
Other languages
Japanese (ja)
Inventor
Tsuneo Horiguchi
Shigeru Tanaka
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Nippon Telegraph and Telephone Corp
Sumitomo Electric Industries Ltd
Original Assignee
Nippon Telegraph and Telephone Corp
Sumitomo Electric Industries Ltd
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 by Nippon Telegraph and Telephone Corp, Sumitomo Electric Industries Ltd filed Critical Nippon Telegraph and Telephone Corp
Priority to JP4433481A priority Critical patent/JPS57158503A/en
Publication of JPS57158503A publication Critical patent/JPS57158503A/en
Pending legal-status Critical Current

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
    • G01B11/00—Measuring arrangements characterised by the use of optical techniques
    • G01B11/02—Measuring arrangements characterised by the use of optical techniques for measuring length, width or thickness

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Length Measuring Devices By Optical Means (AREA)

Abstract

PURPOSE:To measure electric length of an optical fiber with high accuracy, by propagating a laser beam whose amplitude has been modulated by frequency (f), by the optical fiber, and using an approximate expression based on a propagation characteristic from a phase difference of modulated components at an input/ output position and the frequency (f). CONSTITUTION:A continuous light beam of a laser 5 is modulated as to its amplitude by a sine wave of frequency (f) of an oscillator 2, and is made incident to an optical fiber 1. An optical signal which is reflected by the projecting end of the fiber and is returned into the fiber is fetched through a half-mirror 8 of the incident end side and is detected by a photodetector 6. Subsequently, a phase difference (theta) between its detecting signal and a signal of the oscillator 2 is measured by a vector voltmeter 4, and on the other hand, exact frequency (f) of the oscillating signal is measured by a counter 3. Electric length L of the fiber is derived from the approximate expression (theta)=360(f)NL/C regarding said phase difference (provided that N and C denote a constant showing a group refractive index of the fiber, and a light velocity, respectively).
JP4433481A 1981-03-25 1981-03-25 Measuring method of electric length of optical fiber Pending JPS57158503A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP4433481A JPS57158503A (en) 1981-03-25 1981-03-25 Measuring method of electric length of optical fiber

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP4433481A JPS57158503A (en) 1981-03-25 1981-03-25 Measuring method of electric length of optical fiber

Publications (1)

Publication Number Publication Date
JPS57158503A true JPS57158503A (en) 1982-09-30

Family

ID=12688610

Family Applications (1)

Application Number Title Priority Date Filing Date
JP4433481A Pending JPS57158503A (en) 1981-03-25 1981-03-25 Measuring method of electric length of optical fiber

Country Status (1)

Country Link
JP (1) JPS57158503A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61176804A (en) * 1985-01-31 1986-08-08 Hitachi Cable Ltd Method for measuring length of optical fiber by phase change method
EP0325435A2 (en) * 1988-01-21 1989-07-26 Hewlett-Packard Company Method and apparatus for locating discontinuities in optical transmission media
EP0645601A1 (en) * 1993-09-29 1995-03-29 Sollac Measuring procedure and device for the evolution of the ablation length of a tube
JP2001356008A (en) * 2000-06-12 2001-12-26 Advantest Corp Method and apparatus for measuring length of optical device as well as recording medium

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS61176804A (en) * 1985-01-31 1986-08-08 Hitachi Cable Ltd Method for measuring length of optical fiber by phase change method
EP0325435A2 (en) * 1988-01-21 1989-07-26 Hewlett-Packard Company Method and apparatus for locating discontinuities in optical transmission media
EP0325435A3 (en) * 1988-01-21 1991-04-03 Hewlett-Packard Company Method and apparatus for locating discontinuities in optical transmission media
EP0645601A1 (en) * 1993-09-29 1995-03-29 Sollac Measuring procedure and device for the evolution of the ablation length of a tube
FR2710740A1 (en) * 1993-09-29 1995-04-07 Lorraine Laminage Process for measuring the evolution of the length of a nozzle for the introduction of a fluid into a liquid metal contained in a metallurgical vessel, and device for its implementation.
JP2001356008A (en) * 2000-06-12 2001-12-26 Advantest Corp Method and apparatus for measuring length of optical device as well as recording medium

Similar Documents

Publication Publication Date Title
EP0640846A2 (en) Optical measuring apparatus
US4569588A (en) Light frequency change detecting method and apparatus
GB2202324A (en) Optical fibre sensing system
US20080094608A1 (en) Laser velocimetry system
WO1992002912A1 (en) Sensing apparatus
US4380394A (en) Fiber optic interferometer
JPS57158503A (en) Measuring method of electric length of optical fiber
GB2207236A (en) Sensing temperature or pressure distribution
GB2196112A (en) Optical fibre measurement apparatus and method
CN205449326U (en) Device based on laser beat frequency temperature measurement is realized in optic fibre FP chamber
JP2568561B2 (en) Optical interferometer
JP2655647B2 (en) Optical integrated circuit interferometer
JPH0875434A (en) Surface form measuring device
JPS5812539B2 (en) fiber optic equipment
SU1075814A1 (en) Method of measuring linear velocity of object and fibre-optical meter of linear velocity
JPS547361A (en) Detecting method of broken position of optical fibers
JPS643548A (en) Slight differential heat measuring instrument by optical fiber interferometer
RU2031363C1 (en) Method of measuring optical lengths and delays of fiber light guides and other fiber-optic elements
JPS557652A (en) Mode dispersion measuring unit by optical fiber
JPS5448268A (en) Measuring method of rear scattering of optical fibers
SU1142731A1 (en) Measuring system having three-mirror laser-interferometer
SU1620867A1 (en) Device for measuring pressure
SU1637012A1 (en) Device for checking optical pulse duration
SU1277733A1 (en) Fibe-optics measuring device
JPS577534A (en) Measurement of distribution parameter in refractive index of optical fiber