Claims
- 1. A co-directional optical amplifier comprising:
a first optical signal; a second optical signal; a wavelength selective optical coupler, to couple the first and second optical signals; an optical amplifier optically coupled to said wavelength selective optical coupler to amplify the first and second optical signals; and a wavelength selective optical de-coupler optically coupled to the output of said optical amplifier to decouple the first and second optical signals.
- 2. The co-directional optical amplifier of claim 1 further comprising an optical attenuator coupled to said first optical signal and coupled to said wavelength selective optical coupler to equalize the power of the first optical signal.
- 3. The co-directional optical amplifier of claim 1 further comprising an optical attenuator coupled to said second optical signal and coupled to said wavelength selective optical coupler to equalize the power of the first optical signal.
- 4. The co-directional optical amplifier of claim 1 further comprising at least one dispersion compensation module coupled to the wavelength selective optical de-coupler in the path of the first optical signal.
- 5. The co-directional optical amplifier of claim 1 further comprising at least one dispersion compensation module coupled to the wavelength selective optical de-coupler in the path of the second optical signal.
- 6. The co-directional optical amplifier of claim 1 further comprising a gain equalizer coupled to the optical amplifier and the selective optical decoupler.
- 7. The co-directional optical amplifier of claim 1 wherein the optical amplifier is a semiconductor optical amplifier.
- 8. The co-directional optical amplifier of claim 1 wherein the optical amplifier is a discrete Raman amplifier.
- 9. The co-directional optical amplifier of claim 1 wherein the optical amplifier is an erbium doped optical amplifier.
- 10. The co-directional optical amplifier of claim 9 wherein the erbium doped optical amplifier comprises a first stage and a second stage.
- 11. The co-directional optical amplifier of claim 10 further comprising a dispersion compensation module located between the stages of the two stage optical amplifier.
- 12. The co-directional optical amplifier of claim 10 further comprising:
a second optical decoupler connected to the output of the first stage to decouple the first and second optical signals; a first dispersion compensation module connected to the second optical decoupler in the path of the first optical signal; a second dispersion compensation module connected to the second optical decoupler in the path of the second optical signal; and a second optical coupler connected to the first and second dispersion compensation modules to couple the first and second optical signals before entering the input of the second stage.
- 13. The co-directional optical amplifier of claim 11 further comprising at least one dispersion compensation module coupled to the wavelength selective optical de-coupler.
- 14. The apparatus of claim 1 wherein the first optical signal occupies a different wavelength sub-band from the second optical signal.
- 15. The apparatus of claim 1 wherein the first optical signal occupies alternating wavelengths from the second optical signal.
- 16. A method of duplex operation using a co-directional optical amplifier comprising the steps of:
transmitting optical traffic at a first set of wavelengths in a first direction; transmitting optical traffic at a second set of wavelengths in a second direction; coupling the optical traffic at the first set of wavelengths and the optical traffic at the second set of wavelengths using a wavelength selective optical coupler; amplifying the optical traffic at the first set of wavelengths and the optical traffic at the second set of wavelengths in an optical amplifier wherein the optical traffic at the first set of wavelengths and the optical traffic at the second set of wavelengths propagate through said optical amplifier in the same direction; and decoupling the optical traffic at the first set of wavelengths from the optical traffic at the second set of wavelengths using a wavelength selective de-coupler.
- 17. The method of claim 16 wherein the optical traffic at the first set of wavelengths and the optical traffic at the second set of wavelengths is transmitted on the same fiber.
- 18. The method of claim 16 further comprising the step of equalizing the power of the optical traffic at the first set of wavelengths to the power of the optical traffic at the second set of wavelengths using at least one optical attenuator.
- 19. The method of claim 16 further comprising the step of equalizing the gain.
- 20. The method of claim 16 further comprising the step of compensating for dispersion.
- 21. A co-directional optical amplifier comprising:
a first optical fiber carrying a first optical signal in a first direction; a second optical fiber carrying a second optical signal in a second direction; the first fiber connected to a first optical attenuator; the second fiber connected to a second optical attenuator; the first and second optical attenuators connected to an optical coupler; the optical coupler connected to an optical amplifier to amplify the first and second optical signals into a first and second amplified optical signal; the optical amplifier connected to an optical decoupler; the optical decoupler connected to a third optical fiber to carry the first amplified optical signal; and the optical decoupler connected to a fourth optical fiber to carry the second amplified optical signal.
- 22. The co-directional optical amplifier of claim 21 wherein the first optical signal occupies a different wavelength sub-band from the second optical signal.
- 23. The co-directional optical amplifier of claim 21 wherein the first optical signal occupies alternating wavelengths from the second optical signal.
- 24. The co-directional optical amplifier of claim 21 further comprising an equalizing filter coupled to the optical amplifier and the optical de-coupler to equalize the power of the first optical signal.
- 25. The co-directional optical amplifier of claim 21 further comprising an equalizing filter coupled to the optical amplifier and the optical de-coupler to equalize the power of the first optical signal and the second optical filter.
- 26. The co-directional optical amplifier of claim 21 further comprising at least one dispersion compensation module coupled to the wavelength selective optical de-coupler in the path of the first optical signal.
- 27. The co-directional optical amplifier of claim 21 further comprising at least one dispersion compensation module coupled to the wavelength selective optical de-coupler in the path of the second optical signal.
- 28. The co-directional optical amplifier of claim 27 wherein the amplifier comprises a first stage and a second stage.
- 29. The co-directional optical amplifier of claim 28 further comprising a dispersion compensation module located between the first stage and the second stage.
- 30. The co-directional optical amplifier of claim 28 further comprising:
a second optical decoupler connected to the output of the first stage to decouple the first and second optical signals; a first dispersion compensation module connected to the second optical decoupler in the path of the first optical signal; a second dispersion compensation module connected to the second optical decoupler in the path of the second optical signal; and a second optical coupler connected to the first and second dispersion compensation modules to couple the first and second optical signals before entering the input of the second stage.
- 31. The co-directional optical amplifier of claim 29 further comprising at least one dispersion compensation module coupled to the wavelength selective optical de-coupler.
- 32. The co-directional optical amplifier of claim 21 wherein the first optical fiber and the second optical fiber are connected to a directional coupler de-coupler.
- 33. The co-directional optical amplifier of claim 21 wherein the third optical fiber and the forth optical fiber are connected to a directional coupler de-coupler.
- 34. A co-directional amplifier comprising:
a first coupler de-coupler decoupling a unamplified eastbound signal from a first fiber span; a second coupler de-coupler decoupling an unamplified westbound signal from a second fiber span; a wavelength selective coupler coupling the unamplified eastbound signal and the unamplified westbound signal; an amplifier amplifying the unamplified eastbound signal into an amplified eastbound signal and the unamplified westbound signal into an amplified westbound signal; a wavelength selective de-coupler decoupling the amplified eastbound signal and the amplified westbound signal; the first coupler-decoupler coupling the amplified westbound signal to the first fiber span; the second coupler-decoupler coupling the amplified westbound signal to the second fiber span.
- 35. The co-directional optical amplifier of claim 34 further comprising an optical attenuator coupled to the unamplified eastbound signal and coupled to said wavelength selective optical coupler to equalize the power of the unamplified eastbound signal.
- 36. The co-directional optical amplifier of claim 34 further comprising an optical attenuator coupled to the unamplified westbound signal and coupled to said wavelength selective optical coupler to equalize the power of the unamplified westbound signal.
- 37. The co-directional optical amplifier of claim 34 further comprising at least one dispersion compensation module coupled to the wavelength selective optical de-coupler in the path of the amplified eastbound signal.
- 38. The co-directional optical amplifier of claim 34 further comprising at least one dispersion compensation module coupled to the wavelength selective optical de-coupler in the path of the amplified westbound signal.
- 39. The co-directional optical amplifier of claim 34 further comprising a gain equalizer coupled to the optical amplifier and the selective optical decoupler.
- 40. The co-directional optical amplifier of claim 34 wherein the optical amplifier is a semiconductor optical amplifier.
- 41. The co-directional optical amplifier of claim 34 wherein the optical amplifier is a discrete Raman optical amplifier.
- 42. The co-directional optical amplifier of claim 34 wherein the optical amplifier is an erbium doped optical amplifier.
- 43. The co-directional optical amplifier of claim 42 wherein the erbium doped optical amplifier comprises a first stage with a first stage input and a first stage output and a second stage with a second stage input and a second stage output.
- 44. The co-directional optical amplifier of claim 43 further comprising a dispersion compensation module located between the stages of the two stage optical amplifier.
- 46. The co-directional optical amplifier of claim 43 further comprising:
a second optical decoupler connected to the output of the first stage; a first dispersion compensation module connected to the second optical decoupler; a second dispersion compensation module connected to the second optical decoupler; and, a second optical coupler connected to the first and second dispersion compensation modules and the input of the second stage.
- 46. The co-directional optical amplifier of claim 45 further comprising at least one dispersion compensation module coupled to the wavelength selective optical de-coupler.
- 47. The apparatus of claim 1 wherein the unamplified eastbound signal occupies a different wavelength sub-band from the unamplified westbound signal.
- 48. The apparatus of claim 1 wherein the unamplified eastbound signal occupies alternating wavelengths from the unamplified westbound signal.
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority to U.S. Provisional Application Serial No. 60/386,103, entitled “Codirectional Erbium Doped Fiber Amplifier”, by Michael H. Eiselt, filed Jun. 4, 2002,
Provisional Applications (1)
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Number |
Date |
Country |
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60386103 |
Jun 2002 |
US |