JPS5550679A - Laser drive current control system - Google Patents

Laser drive current control system

Info

Publication number
JPS5550679A
JPS5550679A JP12269078A JP12269078A JPS5550679A JP S5550679 A JPS5550679 A JP S5550679A JP 12269078 A JP12269078 A JP 12269078A JP 12269078 A JP12269078 A JP 12269078A JP S5550679 A JPS5550679 A JP S5550679A
Authority
JP
Japan
Prior art keywords
output
signal
drive current
laser
voltage value
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
JP12269078A
Other languages
Japanese (ja)
Inventor
Koichi Oota
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.)
Hitachi Ltd
Original Assignee
Hitachi 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 Hitachi Ltd filed Critical Hitachi Ltd
Priority to JP12269078A priority Critical patent/JPS5550679A/en
Publication of JPS5550679A publication Critical patent/JPS5550679A/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01S—DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL
    • H01S5/00—Semiconductor lasers
    • H01S5/06—Arrangements for controlling the laser output parameters, e.g. by operating on the active medium
    • H01S5/068—Stabilisation of laser output parameters
    • H01S5/06825—Protecting the laser, e.g. during switch-on/off, detection of malfunctioning or degradation

Landscapes

  • Physics & Mathematics (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • General Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Optics & Photonics (AREA)
  • Semiconductor Lasers (AREA)

Abstract

PURPOSE:To reduce the receipt error rate of a light receiver by detecting the increase of a laser drive current when a semiconductor laser starts deteriorating to obtain an alarm signal and operating an automatic gain control circuit in the receiver using the signal and thereby light emitting output is reduced. CONSTITUTION:An input signal 1 is converted by a drive amplifier 6 to a laser drive current 14, which is applied to a semiconductor laser 7 to supply a light output 8 from the laser 7 to a coupler provided separately. In order to prevent the output 8 from varying, an automatic output control circuit having a light receiving element 10 and a comparator 11 is provided to convert part of the output 8 as designated by 9 by the element 10 to an electric signal. Then, the comparator 11 compares the value with the standard voltage value 12 to produce a difference signal 13, which controls the gain of the amplifier 6. A monitor circuit 15 is further provided to always monitor the magnitude of the current 14, and when it conicides with the alarm voltage value 19, it generates an alarm signal 16, and an integrated wave form 18 is formed by an integrator 17 to thereby alter the voltage value 12.
JP12269078A 1978-10-06 1978-10-06 Laser drive current control system Pending JPS5550679A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP12269078A JPS5550679A (en) 1978-10-06 1978-10-06 Laser drive current control system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP12269078A JPS5550679A (en) 1978-10-06 1978-10-06 Laser drive current control system

Publications (1)

Publication Number Publication Date
JPS5550679A true JPS5550679A (en) 1980-04-12

Family

ID=14842200

Family Applications (1)

Application Number Title Priority Date Filing Date
JP12269078A Pending JPS5550679A (en) 1978-10-06 1978-10-06 Laser drive current control system

Country Status (1)

Country Link
JP (1) JPS5550679A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4639924A (en) * 1982-09-03 1987-01-27 Canon Kabushiki Kaisha Drive system for a semiconductor laser
EP0756363A2 (en) * 1995-07-28 1997-01-29 AT&T Corp. Method and apparatus for monitoring performance of a laser transmitter

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4639924A (en) * 1982-09-03 1987-01-27 Canon Kabushiki Kaisha Drive system for a semiconductor laser
EP0756363A2 (en) * 1995-07-28 1997-01-29 AT&T Corp. Method and apparatus for monitoring performance of a laser transmitter
EP0756363A3 (en) * 1995-07-28 1997-11-19 AT&T Corp. Method and apparatus for monitoring performance of a laser transmitter

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