Title:
OPTICAL RESONATOR AND LIGHT FREQUENCY SWEEP DEVICE USING THE SAME
Document Type and Number:
Japanese Patent JP3445481
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To stabilize the polarized state of an output light pulse train caused by restraining the change of the polarized state occurring when a light pulse circulates in an optical ring circuit by making propagated light pass between a light frequency shifter and a Faraday polarized wave rotating element while moving it back and forth in an optical path.
SOLUTION: An FRMa 13 and an FRMb 14 consisting of the Faraday polarized wave rotating element and a mirror accurately rotate the plane of polarization of the light pulse by 90°. The light pulse is frequency-shifted by Δf by means of the light frequency shifter 21, reflected after its polarized state is rotated by 90° in the FRMb 14, and frequency-shifted by the shifter 21 again, then propagated toward a coupler 5. Then, it is moved back and forth in the optical resonator. An optical switch for segmenting a pulse 10 and an optical switch 20 are synchronously controlled by a synchronous control circuit 25 in order to attain periodic actions. As a result, the light pulse train frequency- shifted by 2Δf is periodically obtained from the output port 15 of the coupler 5.
Inventors:
Hiroki Takei
Fumihiko Yamamoto
Tsuneo Horiguchi
Fumihiko Yamamoto
Tsuneo Horiguchi
Application Number:
JP34033897A
Publication Date:
September 08, 2003
Filing Date:
December 10, 1997
Export Citation:
Assignee:
Nippon Telegraph and Telephone Corporation
International Classes:
G02F2/00; G02F2/02; (IPC1-7): G02F2/02
Domestic Patent References:
| JP7199250A |
Attorney, Agent or Firm:
Yoshikazu Tani (1 person outside)