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GB2019561A - Telecommunication systems - Google Patents

Telecommunication systems

Info

Publication number
GB2019561A
GB2019561A GB7913001A GB7913001A GB2019561A GB 2019561 A GB2019561 A GB 2019561A GB 7913001 A GB7913001 A GB 7913001A GB 7913001 A GB7913001 A GB 7913001A GB 2019561 A GB2019561 A GB 2019561A
Authority
GB
United Kingdom
Prior art keywords
subcarrier frequency
fibre
energised
centred
modulators
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.)
Granted
Application number
GB7913001A
Other versions
GB2019561B (en
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.)
Kingsley S A
Original Assignee
Kingsley S A
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 Kingsley S A filed Critical Kingsley S A
Priority to GB7913001A priority Critical patent/GB2019561B/en
Publication of GB2019561A publication Critical patent/GB2019561A/en
Application granted granted Critical
Publication of GB2019561B publication Critical patent/GB2019561B/en
Expired legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/60—Receivers
    • H04B10/66—Non-coherent receivers, e.g. using direct detection
    • H04B10/69—Electrical arrangements in the receiver
    • H04B10/691—Arrangements for optimizing the photodetector in the receiver

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Measurement Of Mechanical Vibrations Or Ultrasonic Waves (AREA)
  • Mechanical Light Control Or Optical Switches (AREA)

Abstract

A telecommunication system has a laser-energised multi mode optical fibre 1. Data is input to the fibre by a series of modulators 4 each operating at a different subcarrier frequency. Optical radiation is detected by quadrant photodetector 3 which applies each of its outputs to respective channel sets. Each channel has a band pass filter 8 centred on a subcarrier frequency followed by a non-linear device 9. The signals from all the channels carrying the same subcarrier frequency are combined and the signals passed through band pass filters 11 centred on the second harmonic of the subcarrier frequency. Each of the modulators 4 consists of a plate bonded by a piezoelectric transducer and a pressure plate between which a length of optical fibre is sandwiched. When the transducer is energised the acoustic energy produced applies asymmetric radial strain to the fibre which induces radial or transverse birefringency, hence phase modulation of orthogonally polarised modes. <IMAGE>
GB7913001A 1978-04-20 1979-04-12 Telecommunication systems Expired GB2019561B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB7913001A GB2019561B (en) 1978-04-20 1979-04-12 Telecommunication systems

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
GB1567278 1978-04-20
GB7913001A GB2019561B (en) 1978-04-20 1979-04-12 Telecommunication systems

Publications (2)

Publication Number Publication Date
GB2019561A true GB2019561A (en) 1979-10-31
GB2019561B GB2019561B (en) 1982-09-02

Family

ID=26251464

Family Applications (1)

Application Number Title Priority Date Filing Date
GB7913001A Expired GB2019561B (en) 1978-04-20 1979-04-12 Telecommunication systems

Country Status (1)

Country Link
GB (1) GB2019561B (en)

Cited By (28)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0047669A3 (en) * 1980-09-08 1982-04-07 Bicc Public Limited Company Telecommunication systems
EP0084958A3 (en) * 1982-01-22 1983-08-10 The Marconi Company Limited Apparatus for controlling the position or movement of a member
EP0074927A3 (en) * 1981-09-11 1985-01-16 Feller Ag. Switching arrangement with an optical fibre
GB2181921A (en) * 1985-10-15 1987-04-29 Plessey Co Plc Optical communications system
GB2182516A (en) * 1985-11-01 1987-05-13 Stc Plc Optical fibre network
US4849960A (en) * 1986-01-24 1989-07-18 Plessey Overseas Limited Optical fibre transducer injected data transmission system
US5220448A (en) * 1990-04-09 1993-06-15 Ascom Tech Ag Bit and frame synchronization unit for an access node of optical transmission equipment
EP0621461A1 (en) * 1993-04-23 1994-10-26 Focas Limited Fibre optic current transducer
EP0637880A1 (en) * 1993-08-04 1995-02-08 AT&T Corp. Optical successive modulation-multiplexing for fiber optical network
WO1996007873A1 (en) * 1994-09-09 1996-03-14 Cookson Group Plc Fibre optic sensor
EP0606170A3 (en) * 1993-01-07 1996-11-20 Nec Corp Optical transmission system and optical network terminals used therein.
US6301033B1 (en) * 1996-06-14 2001-10-09 Hitachi, Ltd. Optical transmission equipment and optical networks
GB2433112A (en) * 2005-12-06 2007-06-13 Schlumberger Holdings Borehole telemetry system
US7656535B2 (en) 2004-12-17 2010-02-02 British Telecommunications Public Limited Company Optical system and method for inferring a disturbance
US7667849B2 (en) 2003-09-30 2010-02-23 British Telecommunications Public Limited Company Optical sensor with interferometer for sensing external physical disturbance of optical communications link
US7697795B2 (en) 2005-03-04 2010-04-13 British Telecommunications Public Limited Company Acoustic modulation
US7755971B2 (en) 2005-03-04 2010-07-13 British Telecommunications Public Limited Company Sensing system
US7796896B2 (en) 2003-09-30 2010-09-14 British Telecommunications Plc Secure optical communication
US7817279B2 (en) 2006-02-24 2010-10-19 British Telecommunications Public Limited Company Sensing a disturbance
US7848645B2 (en) 2004-09-30 2010-12-07 British Telecommunications Public Limited Company Identifying or locating waveguides
US7961331B2 (en) 2006-02-24 2011-06-14 British Telecommunications Public Limited Company Sensing a disturbance along an optical path
US7995197B2 (en) 2004-09-30 2011-08-09 British Telecommunications Public Limited Company Distributed backscattering
US8000609B2 (en) 2005-04-14 2011-08-16 British Telecommunications Public Limited Company Communicating or reproducing an audible sound
US8003932B2 (en) 2005-06-02 2011-08-23 British Telecommunications Public Limited Company Evaluating the position of a disturbance
US8027584B2 (en) 2006-02-24 2011-09-27 British Telecommunications Public Limited Company Sensing a disturbance
US8045174B2 (en) 2004-12-17 2011-10-25 British Telecommunications Public Limited Company Assessing a network
US8396360B2 (en) 2005-03-31 2013-03-12 British Telecommunications Public Limited Company Communicating information
US8670662B2 (en) 2006-04-03 2014-03-11 British Telecommunications Public Limited Company Evaluating the position of an optical fiber disturbance

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB0407386D0 (en) 2004-03-31 2004-05-05 British Telecomm Monitoring a communications link

Cited By (33)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0047669A3 (en) * 1980-09-08 1982-04-07 Bicc Public Limited Company Telecommunication systems
EP0074927A3 (en) * 1981-09-11 1985-01-16 Feller Ag. Switching arrangement with an optical fibre
EP0084958A3 (en) * 1982-01-22 1983-08-10 The Marconi Company Limited Apparatus for controlling the position or movement of a member
GB2181921A (en) * 1985-10-15 1987-04-29 Plessey Co Plc Optical communications system
GB2182516A (en) * 1985-11-01 1987-05-13 Stc Plc Optical fibre network
US4761833A (en) * 1985-11-01 1988-08-02 Stc Plc Optical fibre network
US4849960A (en) * 1986-01-24 1989-07-18 Plessey Overseas Limited Optical fibre transducer injected data transmission system
EP0232041A3 (en) * 1986-01-24 1990-01-24 Plessey Overseas Limited Optical transmission systems using polarization modulation
US5220448A (en) * 1990-04-09 1993-06-15 Ascom Tech Ag Bit and frame synchronization unit for an access node of optical transmission equipment
EP0606170A3 (en) * 1993-01-07 1996-11-20 Nec Corp Optical transmission system and optical network terminals used therein.
EP0621461A1 (en) * 1993-04-23 1994-10-26 Focas Limited Fibre optic current transducer
EP0637880A1 (en) * 1993-08-04 1995-02-08 AT&T Corp. Optical successive modulation-multiplexing for fiber optical network
US5440415A (en) * 1993-08-04 1995-08-08 At&T Corp. Optical successive modulation-muliplexing for fiber optical network
WO1996007873A1 (en) * 1994-09-09 1996-03-14 Cookson Group Plc Fibre optic sensor
US6301033B1 (en) * 1996-06-14 2001-10-09 Hitachi, Ltd. Optical transmission equipment and optical networks
US7667849B2 (en) 2003-09-30 2010-02-23 British Telecommunications Public Limited Company Optical sensor with interferometer for sensing external physical disturbance of optical communications link
US7796896B2 (en) 2003-09-30 2010-09-14 British Telecommunications Plc Secure optical communication
US7848645B2 (en) 2004-09-30 2010-12-07 British Telecommunications Public Limited Company Identifying or locating waveguides
US7995197B2 (en) 2004-09-30 2011-08-09 British Telecommunications Public Limited Company Distributed backscattering
US7656535B2 (en) 2004-12-17 2010-02-02 British Telecommunications Public Limited Company Optical system and method for inferring a disturbance
US8045174B2 (en) 2004-12-17 2011-10-25 British Telecommunications Public Limited Company Assessing a network
US7697795B2 (en) 2005-03-04 2010-04-13 British Telecommunications Public Limited Company Acoustic modulation
US7755971B2 (en) 2005-03-04 2010-07-13 British Telecommunications Public Limited Company Sensing system
US8396360B2 (en) 2005-03-31 2013-03-12 British Telecommunications Public Limited Company Communicating information
US8000609B2 (en) 2005-04-14 2011-08-16 British Telecommunications Public Limited Company Communicating or reproducing an audible sound
US8003932B2 (en) 2005-06-02 2011-08-23 British Telecommunications Public Limited Company Evaluating the position of a disturbance
GB2433112B (en) * 2005-12-06 2008-07-09 Schlumberger Holdings Borehole telemetry system
GB2433112A (en) * 2005-12-06 2007-06-13 Schlumberger Holdings Borehole telemetry system
US9000942B2 (en) 2005-12-06 2015-04-07 Schlumberger Technology Corporation Borehole telemetry system
US7961331B2 (en) 2006-02-24 2011-06-14 British Telecommunications Public Limited Company Sensing a disturbance along an optical path
US8027584B2 (en) 2006-02-24 2011-09-27 British Telecommunications Public Limited Company Sensing a disturbance
US7817279B2 (en) 2006-02-24 2010-10-19 British Telecommunications Public Limited Company Sensing a disturbance
US8670662B2 (en) 2006-04-03 2014-03-11 British Telecommunications Public Limited Company Evaluating the position of an optical fiber disturbance

Also Published As

Publication number Publication date
GB2019561B (en) 1982-09-02

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Legal Events

Date Code Title Description
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
732 Registration of transactions, instruments or events in the register (sect. 32/1977)
PCNP Patent ceased through non-payment of renewal fee