Raman amplifier and optical transmission system using the amplifier
AssigneeFujitsu Limited
InventorsTakao Naito, Toshiki Tanaka
Life of this patent
Estimating the term…
Abstract
A plurality of pump lights are appropriately located in a wavelength band λ1 to λ3. The width of the wavelength band λ1 to λ3 is wider than a Raman shift amount. Gain is obtained in a wavelength band λ2 to λ3 by the plurality of pump lights located in the wavelength band λ1 to λ2. Gain is obtained in a wavelength band λ3 to λ4 by the plurality of pump lights located in the wavelength band λ2 to λ3. As a result, gain can be obtained in a wavelength band λ2 to λ4. A plurality of signal lights are located in the wavelength band λ2 to λ4. The deviation of gain can be adjusted by controlling the power of each of the plurality of pump lights.
Claims26
A Raman amplifier for amplifying multi-wavelength light including a plurality of signal lights, comprising:
- a transmission medium transmitting the multi-wavelength light and a first pump light for amplifying the multi-wavelength light where the multi-wavelength light and the first pump light propagate in an identical direction;
- a light source generating a second pump light for amplifying the multi-wavelength light;
- and
- an optical device guiding the second pump light generated by said light source to the transmission medium, wherein at least one of the first pump light and the second pump light is located within a band of the multi-wavelength light.
A Raman amplifier for amplifying multi-wavelength light including a plurality of signal lights, comprising:
- a transmission medium transmitting the multi-wavelength light;
- a light source generating first pump light located within a band of the multi-wavelength a light and second pump light located out of a band of the multi-wavelength light;
- and
- an optical device guiding the first pump light and the second pump light generated by said light source to the transmission medium wherein the first pump light is located based on the ITU-T grid.
A Raman amplifier for amplifying multi-wavelength light including a plurality of signal lights, comprising:
- a transmission medium transmitting the multi-wavelength light and first pump light where the multi-wavelength light and the first pump light propagate in an identical direction;
- a light source generating second pump light located within a band of the multi-wavelength light and third pump light located out of a band of the multi-wavelength light;
- and
- an optical device guiding the second pump light and the third pump light generated by said light source to the transmission medium.
An optical transmission system in which a Raman amplifier is installed between a first terminal station and a second terminal station, and multi-wavelength light including a plurality of signal lights is transmitted from the first terminal station to the second terminal station, wherein
- the first terminal station comprises:
- a signal light source generating the multi-wavelength light;
- and
- a first pump light source generating first pump light, and
- the Raman amplifier comprises:
- a transmission medium transmitting the multi-wavelength light and the first pump light;
- a second pump light source generating second pump light;
- and
- an optical device guiding the second pump light generated by said second pump light source to the transmission medium, wherein
- at least a part of the first pump light is located within a band of the multi-wavelength light, and wherein
- optical power of the first pump light and the second pump light are adjusted in such a way that gain of the Raman amplifier is equalized.
An optical transmission system in which a Raman amplifier is installed between a first terminal station and a second terminal station, and multi-wavelength light including a plurality of signal lights is transmitted from the first terminal station to the second terminal station, wherein
- the first terminal station comprises:
- a signal light source generating the multi-wavelength light, and
- the Raman amplifier comprises:
- a transmission medium transmitting the multi-wavelength light;
- a first pump light source generating first pump light located within a band of the multi-wavelength light;
- a second pump light source generating second pump light located out of a band of the multi-wavelength light;
- and
- an optical device guiding the first pump light generated by said first pump light source and the second pump light generated by said second pump light source to the transmission medium, wherein
- optical power of the first pump light and the second pump light are adjusted in such a way that gain of the Raman amplifier is equalized.
A Raman amplifier for amplifying multi-wavelength light including a plurality of signal lights, comprising:
- a transmission medium transmitting the multi-wavelength light and auxiliary light with a longer wavelength than a wavelength of the multi-wavelength light;
- a light source generating pump light for amplifying the multi-wavelength light;
- and
- an optical device guiding the pump light generated by said light source to the transmission line.
A Raman amplifier for amplifying multi-wavelength light including a plurality of signal lights, comprising:
- a transmission medium transmitting the multi-wavelength light;
- a light source generating pump light for amplifying the multi-wavelength light and auxiliary light with a longer wavelength than a wavelength of the multi-wavelength light;
- and
- an optical device guiding the pump light and auxiliary light generated by said light source to the transmission medium.
An optical transmission system in which a Raman amplifier is installed between a first terminal station and a second terminal station, and multi-wavelength light including a plurality of signal lights is transmitted from the first terminal station to the second terminal station, wherein
- the first terminal station comprises:
- a signal light source generating the multi-wavelength light;
- and
- an auxiliary light source generating auxiliary light with a longer wavelength than a wavelength of the multi-wavelength light, and
- the Raman amplifier comprises:
- a transmission medium transmitting the multi-wavelength light and the auxiliary light;
- a pump light source generating pump light for amplifying the multi-wavelength light;
- and
- an optical device guiding the pump light generated by said pump light source to the transmission medium, wherein
- optical power of the auxiliary light is adjusted in such a way that a gain of the Raman amplifier is equalized.
An optical transmission system in which a Raman amplifier is installed between a first terminal station and a second terminal station, and multi-wavelength light including a plurality of signal lights is transmitted from the first terminal station to the second terminal station, wherein
- the first terminal station comprises:
- a signal light source generating the multi-wavelength light, and
- the Raman amplifier comprises:
- a transmission medium transmitting the multi-wavelength light;
- a pump light source generating pump light for amplifying the multi-wavelength light;
- an auxiliary light source generating auxiliary light with a longer wavelength than a wavelength of the multi-wavelength light;
- and
- an optical device guiding the pump light generated by said pump light source and the auxiliary light generated by said auxiliary light source to the transmission medium, wherein
- optical power of the auxiliary light is adjusted in such a way that a gains of the Raman amplifier is equalized.
An optical transmission system in which multi-wavelength light including a plurality of signal lights is amplified by a Raman amplifier, wherein
- the Raman amplifier amplifies the multi-wavelength light using a plurality of pump lights located at frequency intervals of 1/n of Raman shift amount (n is an integer).
An optical transmission system in which multi-wavelength light including a plurality of signal lights is amplified by a Raman amplifier and a rare-earth doped fiber amplifier, wherein
- the Raman amplifier amplifies the multi-wavelength light using a plurality of pump lights located at frequency intervals of 1/n of Raman shift amount, and wherein
- the rare-earth-doped fiber amplifier is composed of a plurality of amplification units corresponding to the plurality of pump lights, and each amplification unit amplifies signal light in a corresponding wavelength band (n is an integer).
An optical transmission system in which multi-wavelength light including a plurality of signal lights is amplified by a Raman amplifier and a rare-earth doped fiber amplifier, wherein
- the Raman amplifier amplifies the multi-wavelength light using a plurality of pump lights located at frequency intervals of 1/(n+0.5) of Raman shift amount, and wherein
- the rare-earth-doped fiber amplifier is composed of a plurality of amplification units corresponding to the plurality of pump lights, and each amplification unit amplifies signal light in a corresponding wavelength band (n is an integer).
An optical transmission system in which multi-wavelength light including a plurality of signal lights is amplified by a Raman amplifier, wherein
- the Raman amplifier amplifies the multi-wavelength light using pump light located within a band of the multi-wavelength light, and wherein
- a supervisory signal for monitoring a state of this transmission system is located in a vicinity of pump light which is located within a band of the multi-wavelength light and wherein a transmission rate of the supervisory signal is much lower than that of signals transmitted by the multi-wavelength light.
Dependencies are inferred from the claim text.