Claims
- 1. An optical signal amplifier comprising:
at least one source of pumping light, said source being configured to produce pumping light having a predominant polarization state; at least one depolarizer comprising a birefringent optical component having a principal axis oriented at about 45 degrees with respect to said predominant polarization state and coupled to receive said pumping light as an input and having as an output a pumping beam, wherein said output pumping beam has a degree of polarization in an inclusive range of greater than 1% through approximately 40%; and a Raman gain medium configured to receive said pumping beam and optical signals as inputs and to transfer energy from said pumping beam to said optical signals via stimulated Raman scattering.
- 2. The amplifier of claim 1, wherein said Raman gain medium being a single mode optical fiber.
- 3. The amplifier of claim 2, wherein said Raman gain medium being a single mode fiber that is forward pumped.
- 4. The amplifier of claim 2, wherein said Raman gain medium being a single mode fiber that is backward pumped.
- 5. The amplifier of claim 4, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of greater than 1% through 15%.
- 6. The amplifier of claim 5, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 2% through 13%.
- 7. The amplifier of claim 6, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 3% through 11%.
- 8. The amplifier of claim 7, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 4% through 10%.
- 9. The amplifier of claim 8, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 5% through 9%.
- 10. The amplifier of claim 9, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 6% through 7%.
- 11. The amplifier of claim 3, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 1% through 10%.
- 12. The amplifier of claim 11, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 2% through 9%.
- 13. The amplifier of claim 12, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 3% through 7%.
- 14. The amplifier of claim 13, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 4% through 6%.
- 15. The amplifier of claim 1, wherein said Raman gain medium being a non-zero dispersion shifted fiber.
- 16. The amplifier of claim 15, wherein said Raman gain medium being a non-zero dispersion shifted fiber that is backward pumped.
- 17. The amplifier of claim 16, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of greater than 1% through 20%.
- 18. The amplifier of claim 17, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 2% through 16%.
- 19. The amplifier of claim 18, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 3% through 12%.
- 20. The amplifier of claim 19, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 4% through 8%.
- 21. The amplifier of claim 20, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 5% through 7%.
- 22. The amplifier of claim 21, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization of about 6%.
- 23. The amplifier of claim 15, wherein said Raman gain medium being a non-zero dispersion shifted fiber that is forward pumped.
- 24. The amplifier of claim 23, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 1% through 9%.
- 25. The amplifier of claim 24, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 2% through 8%.
- 26. The amplifier of claim 25, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 3% through 7%.
- 27. The amplifier of claim 26, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 4% through 6%.
- 28. The amplifier of claim 27, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of about 5%.
- 29. The amplifier of claim 1, wherein said Raman gain medium being a dispersion compensation fiber that is forward pumped.
- 30. The amplifier of claim 29, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of greater than 1% through 20%.
- 31. The amplifier of claim 30, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 2% through 16%.
- 32. The amplifier of claim 31, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 3% through 12%.
- 33. The amplifier of claim 32, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 4% through 8%.
- 34. The amplifier of claim 33, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 5% through 7%.
- 35. The amplifier of claim 34, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization of about 6%.
- 36. A method of managing polarization dependent gain in a Raman amplifier comprising:
routing laser light having a predominant polarization state through a single birefringent component that has a principal axis oriented at about 45 degrees with respect to said predominant polarization state so as to produce a pumping beam which has a degree of polarization in an inclusive range of greater than 1% through about 40%; and routing said pumping beam to a Raman gain medium.
- 37. The method of claim 36, wherein said Raman gain medium being a single mode optical fiber.
- 38. The method of claim 37, wherein said Raman gain medium being a single mode fiber that is forward pumped.
- 39. The method of claim 37, wherein said Raman gain medium being a single mode fiber that is backward pumped.
- 40. The method of claim 39, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of greater than 1% through 15%.
- 41. The method of claim 40, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 2% through 13%.
- 42. The method of claim 41, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 3% through 11%.
- 43. The method of claim 42, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 4% through 10%.
- 44. The method of claim 43, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 5% through 9%.
- 45. The method of claim 44, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 6% through 7%.
- 46. The method of claim 38, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 1% through 10%.
- 47. The method of claim 46, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 2% through 9%
- 48. The method of claim 47, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 3% through 7%.
- 49. The method of claim 48, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 4% through 6%.
- 50. The method of claim 36, wherein said Raman gain medium being a non-zero dispersion shifted fiber.
- 51. The method of claim 50, wherein said Raman gain medium being a non-zero dispersion shifted fiber that is backward pumped.
- 52. The method of claim 51, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of greater than 1% through 20%.
- 53. The method of claim 52, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 2% through 16%.
- 54. The method of claim 53, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 3% through 12%.
- 55. The method of claim 54, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 4% through 8%.
- 56. The method of claim 55, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 5% through 7%.
- 57. The method of claim 54, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization of about 6%.
- 58. The method of claim 50, wherein said Raman gain medium being a non-zero dispersion shifted fiber that is forward pumped.
- 59. The method of claim 58, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 1% through 9%.
- 60. The method of claim 59, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 2% through 8%.
- 61. The method of claim 60, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 3% through 7%.
- 62. The method of claim 61, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of above 4% through 6%.
- 63. The method of claim 62, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of about 5%.
- 64. The method of claim 36, wherein said Raman gain medium being a forward pumped dispersion compensating fiber.
- 65. The method of claim 64, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of greater than 1% through 20%.
- 66. The method of claim 65, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 2% through 16%.
- 67. The method of claim 66, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 3% through 12%.
- 68. The method of claim 67, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 4% through 8%.
- 69. The method of claim 68, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization in an inclusive range of 5% through 7%.
- 70. The method of claim 69, wherein said depolarizer is configured to provide an output pumping beam that has a degree of polarization of about 6%.
- 71. (Amended) A light source for pumping a Raman gain medium in a Raman amplifier comprising:
a laser light source configured to produce an output light beam having a predominant polarization state; a single birefringent component having an input port and an output port, wherein said input port is configured to receive said output light beam and having a principal axis oriented at about 45 degrees with respect to said predominant polarization state so as to produce a pumping beam which has a degree of polarization in an inclusive range of greater than 1% through about 40%, and wherein said output port is configured to couple said pumping beam to said Raman gain medium.
- 72. The light source of claim 71, wherein said Raman gain medium being a single mode optical fiber.
- 73. The light source of claim 72, wherein said Raman gain medium being a single mode fiber that is forward pumped.
- 74. The light source of claim 73, wherein said Raman gain medium being a single mode fiber that is backward pumped.
- 75. The light source of claim 71, wherein said Raman gain medium being a non-zero dispersion shifted optical fiber.
- 76. The light source of claim 75, wherein said Raman gain medium being a non-zero dispersion shifted optical fiber that is forward pumped.
- 77. The light source of claim 75, wherein said Raman gain medium being a non-zero dispersion shifted fiber that is backward pumped.
- 78. The light source of claim 71, wherein said Raman gain medium being a dispersion compensating fiber that is forward pumped.
Priority Claims (1)
Number |
Date |
Country |
Kind |
11-251528 |
Sep 1999 |
JP |
|
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
[0001] The present application is a continuation-in-part of co-pending and commonly owned U.S. application Ser. No. 09/654,974, filed on Sep. 5, 2000, the entire contents of which being incorporated herein by reference.
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
09654974 |
Sep 2000 |
US |
Child |
10645528 |
Aug 2003 |
US |