JPS56100539A - Light agc system - Google Patents

Light agc system

Info

Publication number
JPS56100539A
JPS56100539A JP329880A JP329880A JPS56100539A JP S56100539 A JPS56100539 A JP S56100539A JP 329880 A JP329880 A JP 329880A JP 329880 A JP329880 A JP 329880A JP S56100539 A JPS56100539 A JP S56100539A
Authority
JP
Japan
Prior art keywords
signal
light
light input
circuit
amplitude
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
JP329880A
Other languages
Japanese (ja)
Inventor
Yoshitsugu Yamanashi
Takashi Kihara
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 JP329880A priority Critical patent/JPS56100539A/en
Publication of JPS56100539A publication Critical patent/JPS56100539A/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
    • H04B10/60—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
    • H04B10/6911—Photodiode bias control, e.g. for compensating temperature variations
    • 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
    • H04B10/67—Optical arrangements in the receiver
    • 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
    • H04B10/67—Optical arrangements in the receiver
    • H04B10/671—Optical arrangements in the receiver for controlling the input optical signal
    • H04B10/672—Optical arrangements in the receiver for controlling the input optical signal for controlling the power of the input optical signal
    • H04B10/674—Optical arrangements in the receiver for controlling the input optical signal for controlling the power of the input optical signal using a variable optical attenuator
    • 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
    • H04B10/693—Arrangements for optimizing the preamplifier in the receiver
    • H04B10/6931—Automatic gain control of the preamplifier

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Control Of Amplification And Gain Control (AREA)
  • Optical Communication System (AREA)

Abstract

PURPOSE:To extend the automatic gain adjustment range, by providing a light quantity control part in the automatic gain adjusting circuit. CONSTITUTION:When the light input is not large, the conventional AGC circuit is operated. That is, the light signal is converted to an electric signal by avalanche photodiode (APD) 1, and the signal obtained by detecting the amplitude by amplitude detector 2 is fed back to bias circuit 3 or electric AGC circuit 4 of APD1 to make the taken-out signal amplitude fixed. Meanwhile, the AGC signal is monitored; and if the light input becomes so large that it cannot be compensated by the conventional AGC system, light quantity control part 6 is operated by comparator 5 to reduce the light input, thereby making the light input into the range where it is compensated by the conventional AGC circuit.
JP329880A 1980-01-16 1980-01-16 Light agc system Pending JPS56100539A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP329880A JPS56100539A (en) 1980-01-16 1980-01-16 Light agc system

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP329880A JPS56100539A (en) 1980-01-16 1980-01-16 Light agc system

Publications (1)

Publication Number Publication Date
JPS56100539A true JPS56100539A (en) 1981-08-12

Family

ID=11553460

Family Applications (1)

Application Number Title Priority Date Filing Date
JP329880A Pending JPS56100539A (en) 1980-01-16 1980-01-16 Light agc system

Country Status (1)

Country Link
JP (1) JPS56100539A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0160324A2 (en) * 1984-05-04 1985-11-06 Alcatel SEL Aktiengesellschaft Optical receiver

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0160324A2 (en) * 1984-05-04 1985-11-06 Alcatel SEL Aktiengesellschaft Optical receiver
JPS6128243A (en) * 1984-05-04 1986-02-07 スタンダ−ド・エレクトリツク・ロ−レンツ・アクチエンゲゼルシヤフト Light receiver
EP0160324A3 (en) * 1984-05-04 1988-03-16 Alcatel SEL Aktiengesellschaft Optical receiver

Similar Documents

Publication Publication Date Title
JPS56100539A (en) Light agc system
JPS5437403A (en) Automatic gain control method for light receiving circuit
JPS5488704A (en) Automatic gain control system
JPS6416036A (en) Automatic reception level control system for coherent light communication
JPS5583280A (en) Output stabilizing system for semiconductor laser
JPS6455995A (en) Automatic white balance correcting device
JPS56140789A (en) Color balance control circuit
JPS56169443A (en) Detecting circuit for input signal interruption
JPS5338244A (en) Automatic gain control system by pilot signal
JPS6436131A (en) Automatic gain control system for optical receiver
JPS56143738A (en) Automatic gain controlling system of light receiver
JPS5776946A (en) Automatic gain control system
JPS5742218A (en) Delay automatic gain control circuit
JPS56111430A (en) Detector for fine vibration
JPS5721181A (en) Television camera
JPS5379453A (en) Automatic gain control system
JPS6468083A (en) Signal discriminating device
JPS57188163A (en) Signal discriminator
JPS5550679A (en) Laser drive current control system
JPS6427323A (en) Transmission equipment
JPS5390802A (en) Control system for light receiving system
JPS5769982A (en) Audio reception circuit for television receiver
JPS577645A (en) Optical receiving circuit
JPS5515030A (en) Infrared spectrophotometer
JPS6422122A (en) Light reception circuit