JPS57172787A - Semiconductor laser protection - Google Patents

Semiconductor laser protection

Info

Publication number
JPS57172787A
JPS57172787A JP5753281A JP5753281A JPS57172787A JP S57172787 A JPS57172787 A JP S57172787A JP 5753281 A JP5753281 A JP 5753281A JP 5753281 A JP5753281 A JP 5753281A JP S57172787 A JPS57172787 A JP S57172787A
Authority
JP
Japan
Prior art keywords
laser
circuit
semiconductor laser
control loop
output control
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
JP5753281A
Other languages
Japanese (ja)
Inventor
Isamu Shibata
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.)
Ricoh Co Ltd
Original Assignee
Ricoh Co 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 Ricoh Co Ltd filed Critical Ricoh Co Ltd
Priority to JP5753281A priority Critical patent/JPS57172787A/en
Publication of JPS57172787A publication Critical patent/JPS57172787A/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 prevent an overcurrent flowing into a laser by a method wherein an output control loop is provided with a voltage limiting circuit in a semiconductor laser device having the output control loop and a switching circuit is also provided in series with the laser to delay the switch at the time of turning on a power source. CONSTITUTION:When a series circuit consisting of a semiconductor laser LD, a transistor Tr1 and a resistor R1 is formed between a voltage source V and a ground, a switching circuit 4 is inserted between the voltage source V and the laser LD. An output control loop consisting of a photodetector 1, a comparator 2 in which a reference voltage (a) is applied, and an operational amplifier OP1 is provided and a voltage limiting circuit 3 is inserted between the comparator 2 and the amplifier OP1 when the output in the amplifier OP1 is connected to the base of a transistor Tr1. In this composition, the circuit 4 is delayed when a voltage source V is made in hot line condition and the driving current in the laser LD is limited by the circuit 3 to prevent the deterioration or breakdown of the laser LD.
JP5753281A 1981-04-16 1981-04-16 Semiconductor laser protection Pending JPS57172787A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP5753281A JPS57172787A (en) 1981-04-16 1981-04-16 Semiconductor laser protection

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP5753281A JPS57172787A (en) 1981-04-16 1981-04-16 Semiconductor laser protection

Publications (1)

Publication Number Publication Date
JPS57172787A true JPS57172787A (en) 1982-10-23

Family

ID=13058352

Family Applications (1)

Application Number Title Priority Date Filing Date
JP5753281A Pending JPS57172787A (en) 1981-04-16 1981-04-16 Semiconductor laser protection

Country Status (1)

Country Link
JP (1) JPS57172787A (en)

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