JPS54129904A - Doubling system of light source - Google Patents

Doubling system of light source

Info

Publication number
JPS54129904A
JPS54129904A JP3795678A JP3795678A JPS54129904A JP S54129904 A JPS54129904 A JP S54129904A JP 3795678 A JP3795678 A JP 3795678A JP 3795678 A JP3795678 A JP 3795678A JP S54129904 A JPS54129904 A JP S54129904A
Authority
JP
Japan
Prior art keywords
light source
outputs
normal
constant value
stand
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
JP3795678A
Other languages
Japanese (ja)
Inventor
Akira Miyata
Masanori Honda
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.)
Fujitsu Ltd
Original Assignee
Fujitsu 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 Fujitsu Ltd filed Critical Fujitsu Ltd
Priority to JP3795678A priority Critical patent/JPS54129904A/en
Publication of JPS54129904A publication Critical patent/JPS54129904A/en
Pending 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
    • H04B10/03—Arrangements for fault recovery
    • H04B10/032—Arrangements for fault recovery using working and protection systems
    • 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

Abstract

PURPOSE:To prolong the lifetime of a stand-by light source by making the current control circuit of the stand-by light source keep the signal component of the driving current of an in-use light source low or at a normal value when the electric signal of the detection circuit of the in-use light source is normal or decreases below a certain value correspondingly. CONSTITUTION:Some of a light output is branched 4 and 4' and detecting circuits 5 and 5' make the photoelectric conversion of the outputs; and signal components of driving currents for laser diodes LD 3 and LD3' are controlled to a constant value by the outputs of current control circuits 6 and 9 corresponding to electric signals from circuits 5 and 5', and by the outputs, laser diodes LD3 and LD3' are driven. Namely, light sources 3 and 3' are provided which generate photo output 8 of the constant value, and light outputs from both the light sources are mixed into one and coupled with one fiber. Here, when the electric signal of detection circuit 5 of in-use light source 3 is normal or decreases below the constant value, current control circuit 9 of stand-by light source 3' controls the signal component of the driving current of diode 3 to a low-level constant value or normal value correspondingly. Therefore, the lifetime of light source 3' can be prolonged with the reliability of the system maintained.
JP3795678A 1978-03-31 1978-03-31 Doubling system of light source Pending JPS54129904A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP3795678A JPS54129904A (en) 1978-03-31 1978-03-31 Doubling system of light source

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP3795678A JPS54129904A (en) 1978-03-31 1978-03-31 Doubling system of light source

Publications (1)

Publication Number Publication Date
JPS54129904A true JPS54129904A (en) 1979-10-08

Family

ID=12511996

Family Applications (1)

Application Number Title Priority Date Filing Date
JP3795678A Pending JPS54129904A (en) 1978-03-31 1978-03-31 Doubling system of light source

Country Status (1)

Country Link
JP (1) JPS54129904A (en)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56105686A (en) * 1980-01-28 1981-08-22 Canon Inc Controller for quantity of light
JPS6089990A (en) * 1983-10-21 1985-05-20 Sumitomo Electric Ind Ltd Optical integrated circuit

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS56105686A (en) * 1980-01-28 1981-08-22 Canon Inc Controller for quantity of light
JPS6342432B2 (en) * 1980-01-28 1988-08-23 Canon Kk
JPS6089990A (en) * 1983-10-21 1985-05-20 Sumitomo Electric Ind Ltd Optical integrated circuit
JPH0426233B2 (en) * 1983-10-21 1992-05-06 Sumitomo Electric Industries

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