Claims
- 1. A polarization insensitive semiconductor optical amplifier module, the module comprising:
a semiconductor optical amplifier; and a polarization dependent loss unit optically coupled to the semiconductor optical amplifier; the polarization dependent loss unit providing loss based on the polarization of light provided to the polarization dependent loss unit, the polarization dependent loss unit having loss that makes the semiconductor optical amplifier module less polarization sensitive; and wherein the semiconductor optical amplifier and the polarization dependent loss unit are packaged together as a module.
- 2. The module of claim 1, wherein the semiconductor optical amplifier is a gain-clamped semiconductor optical amplifier.
- 3. The module of claim 1, wherein the polarization dependent loss unit is optically coupled to the output of the semiconductor optical amplifier.
- 4. The module of claim 1, wherein the polarization dependent loss unit has a loss that is matched to the polarization dependent gain of the semiconductor optical amplifier.
- 5. The module of claim 1, wherein the polarization dependent loss unit is variable in the amount of loss that is provided.
- 6. The module of claim 1, wherein the polarization dependent loss unit also provides tunable polarization independent loss.
- 7. The module of claim 1, wherein the polarization dependent loss unit is a polarizing fiber having a pre-defined length.
- 8. The module of claim 1, wherein the polarization dependent loss unit is a polarizing fiber having a pre-defined rotational position with respect to the semiconductor optical amplifier.
- 9. The module of claim 1, wherein the polarization dependent loss unit is a parallel metallic strip polarizer.
- 10. The module of claim 9, wherein the parallel metallic strip polarizer has variable broken lines to create variable polarization dependent loss across filter, and filter is mounted in a movable position to tune the polarization dependent loss amplitude, and a rotatable position to tune loss to TE/TM.
- 11. The module of claim 1, wherein the polarization dependent loss unit comprises a first optical fiber and a second optical fiber butt coupled, with an axis of the second optical fiber offset from an axis of the first optical fiber.
- 12. The module of claim 1, wherein the polarization dependent loss unit comprises an optical fiber bent to a pre-determined angle to produce matching polarization dependent loss.
- 13. The module of claim 1, wherein:
the semiconductor optical amplifier has an input facet and an output, and has a tilted stripe that is angled with respect to cleave planes of the semiconductor optical amplifier; and the polarization dependent loss unit is a thin film coating on the input facet of the semiconductor optical amplifier, the thin film having a thickness such that the polarization dependent loss is about the same as the polarization dependent gain of the semiconductor optical amplifier.
- 14. The module of claim 1, wherein:
the semiconductor optical amplifier has a tilted stripe that is angled with respect to cleave planes of the semiconductor optical amplifier; and the polarization dependent loss unit is a thin film coating on the output facet of the semiconductor optical amplifier, the thin film having a thickness such that the polarization dependent loss is about the same as the polarization dependent gain of the semiconductor optical amplifier.
- 15. The module of claim 14, wherein the thin film is any material used as an anti-reflective coating.
- 16. The module of claim 14, wherein the thin film is one from the group of aluminum nitride, aluminum oxide, titanium oxide, silicon, silicon oxide, yitrium oxide, zirconium oxide.
- 17. The module of claim 14, wherein the thin film is a plurality of layers of one or more materials.
- 18. The module of claim 1, wherein the polarization dependent loss unit is a fiber positioned such that the axis of the fiber is at a predetermined angle with respect to a axis of an active region of the semiconductor optical amplifier.
- 19. A method for manufacturing a polarization insensitive semiconductor optical amplifier module, the method comprising the step of:
determining a polarization dependent gain of a semiconductor optical amplifier; determining a polarization dependent loss of at least one polarization dependent loss unit; selecting a polarization dependent loss unit that has a polarization dependent loss that reduces the polarization sensitivity of the semiconductor optical amplifier; optically coupling the selected polarization dependent loss unit to the semiconductor optical amplifier; and packaging the selected polarization dependent loss unit and the semiconductor optical amplifier as a semiconductor optical amplifier module.
- 20. The method of claim 19, wherein the selected polarization dependent loss unit is a variable polarization dependent loss unit, and the method further comprises the step of tuning the loss of the PDL unit to make the semiconductor optical amplifier module polarization insensitive.
- 21. The method of claim 19, wherein the step of determining a polarization dependent loss of at least one polarization dependent loss unit comprises the step of determining the polarization dependent loss of a plurality of fibers having different lengths.
- 22. The method of claim 19, wherein the step of determining a polarization dependent loss of at least one polarization dependent loss unit comprises the step of determining the polarization dependent loss of a fibers based on a plurality of rotational orientations.
- 23. The method of claim 19, wherein the step of determining a polarization dependent loss of at least one polarization dependent loss unit comprises the step of determining the polarization dependent loss of a first fiber and a second fiber at a plurality of offsets from each other.
- 24. The method of claim 18, wherein the step of determining a polarization dependent loss of at least one polarization dependent loss unit comprises the step of determining the polarization dependent loss of a fiber bent at a plurality of different angles.
- 25. A polarization insensitive semiconductor optical amplifier module, the module comprising:
a semiconductor optical amplifier having polarization dependent gain; and a polarization dependent gain unit optically coupled to the semiconductor optical amplifier; the polarization dependent gain unit providing gain based on the polarization of light provided to the polarization dependent gain unit, the polarization dependent gain unit having gain that makes the semiconductor optical amplifier module less polarization sensitive; and wherein the semiconductor optical amplifier and the polarization dependent gain unit are packaged together as a module.
- 26. The module of claim 25, wherein the polarization dependent gain unit is a gain-clamped semiconductor optical amplifier.
- 27. The module of claim 25, wherein the semiconductor optical amplifier is a gain-clamped semiconductor optical amplifier.
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application relates to U.S. patent application Ser. No. 09/273,813, entitled “Tunable-Gain Lasing Semiconductor Optical Amplifier,” filed on Mar. 22, 1999, which is incorporated herein by reference, and U.S. patent application Ser. No. 09/09/416,817, entitled “Low-Noise, High-Power Optical Amplifier,” filed on Oct. 12, 1999, which is incorporated herein by reference.
Continuations (1)
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Number |
Date |
Country |
Parent |
09585587 |
Jun 2000 |
US |
Child |
09956175 |
Sep 2001 |
US |