Claims
- 1. An optical communications system, comprising:a transmitting station transmitting a wavelength division multiplexed (WDM) optical signal which includes first and second optical signals at different wavelengths multiplexed together; a branch station transmitting an optical signal with the same wavelength as the second optical signal in the WDM optical signal; a branching unit branching the second optical signal from the WDM optical signal transmitted by the transmitting station, transmitting the branched second optical signal to the branch station, and combining the optical signal transmitted by the branch station with the WDM optical signal having the second optical signal branched therefrom, to produce a combined signal; a receiving station receiving the combined signal; and a power level controller causing power levels in the combined signal of the first optical signal and the optical signal transmitted by the branch station to be equal, and having an optical attenuator adjusting the power level of the optical signal transmitted by the branch station.
- 2. The optical communications system according to claim 1, whereinthe power level controller compares the power level of the WDM optical signal with the power level of the optical signal transmitted by the branch station, and adjusts the power level of the optical signal transmitted by the branch station based on a comparison result.
- 3. The optical communications system according to claim 2, wherein the power level controller comprises:an optical amplifier capable of adjusting a gain; and a gain adjustor adjusting the power level of the optical signal transmitted by the branch station by changing the gain of the optical amplifier.
Priority Claims (2)
Number |
Date |
Country |
Kind |
8-282822 |
Sep 1996 |
JP |
|
9-208899 |
Aug 1997 |
JP |
|
Parent Case Info
This application is a divisional of application Ser. No. 09/779,624, filed Feb. 9, 2001, now U.S. Pat. No. 6,414,770, which is a divisional of application Ser. No. 08/923,934 filed Sep. 5, 1997, now U.S. Pat. No. 6,233,076.
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Non-Patent Literature Citations (3)
Entry |
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