Title:
OPTICAL REPEATER
Document Type and Number:
Japanese Patent JP3132464
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To reduce a feeding current in an optical relay system that is driven by constant current drive by providing a 2nd current control element which is parallelly connected to a serial circuit of a laser diode and a 1st current control element.
SOLUTION: A photodiode 2a receives a part of excitation light emitted from a laser diode 1a and a current control circuit 5 controls a base voltage of a transistor 3a so that the excitation light level can become constant. A circuit comprising the diode 1a, the photodiode 2a and the transistor 3a is made an incoming interchange circuit. A circuit comprising a laser diode 1b, a photodiode 2b and a transistor 3b operates in the same manner and is made an outgoing interchange circuit. About a transistor 4 which is parallelly connected to the two incoming and outgoing circuits, a base voltage is controlled by the circuit 5 so that the sum of currents which flow in the incoming and outgoing interchange circuits and the transistor 4 can be equal to a current value of a constant current source 6.
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Inventors:
Hideya Okazaki
Application Number:
JP9916698A
Publication Date:
February 05, 2001
Filing Date:
April 10, 1998
Export Citation:
Assignee:
NEC
International Classes:
H01S3/094; H01S3/06; H01S3/067; H01S3/0941; H01S3/10; H04B10/07; H04B10/29; H04B10/293; H04B10/297; H04B10/80; (IPC1-7): H04B10/17; H01S3/094; H04B10/02; H04B10/16
Domestic Patent References:
| JP5268167A | ||||
| JP6237227A | ||||
| JP7154310A |
Attorney, Agent or Firm:
Tadao Hirata