OPTICAL PHASE SYNCHRONIZING LIGHT SOURCE

Japanese Patent JP3459166

B2

PROBLEM TO BE SOLVED: To reduce a band width required for an optical phase locked loop and to perform optical phase synchronizing for signal light from a laser beam source having an oscillation light frequency flicker by combining an optical phase locked loop method with a light injection synchronizing method.
SOLUTION: A part of input signal light is branched by an optical branching unit 11 to be inputted to an injection synchronizing light source 12, and injection synchronizing light synchronized with the optical frequency of the carrier component of the input signal light is outputted. This injection synchronizing light is inputted to an optical frequency shifter 13, and the optical frequency is shifted by δf, and the injection synchronizing light E2 and the branched input signal light E1 are inputted to an optical synthesizing unit 14 of two inputs two outputs to be synthesized, and a part of outputted synthesized light E1+E2, E1-E2 are branched by the optical branching units 15-1, 15-2 to be inputted to a light phase detector 16. Then, a phase error signal from the light phase detector 16 is fed back to a control circuit 17 driving the light frequency shifter 13, and a light frequency shift δf imparted to the injection synchronizing light is controlled, and the light frequency and the light phase between the input signal light E1 and the injection synchronizing light E2 are synchronized.

Koh Imajuku
Atsushi Takada

JP30169097A

October 20, 2003

November 04, 1997

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Nippon Telegraph and Telephone Corporation

G02F2/02; H03L7/08; H04B10/00; (IPC1-7): G02F2/02; H03L7/08; H04B10/00

JP8136959A

Furuya Fumio

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