Granted Patent B2

US 7,515,780 · App. 11/586,093 · Granted Apr 7, 2009

Abstract

Claims (23)

1. A fiber optical isolator comprising:

a first isolator stage comprising:

a Faraday rotator configured to adjust the polarity of a light beam;

a heat sink coupled to the Faraday rotator and configured to dissipate heat generated in the Faraday rotator by the light beam, and

an input port coupled to the first isolator stage, wherein the input port is aligned to achieve an insertion loss that decreases as optical power increases to at least one level greater than 2 watts.

2. The fiber optical isolator, as set forth in claim 1 , comprising a second isolator stage coupled in series with the first isolator stage, wherein the second isolator stage is substantially similar to the first isolator stage.

3. The fiber optical isolator, as set forth in claim 1 , comprising a polarizer arrayed in an optical line of sight with the Faraday rotator.

4. The fiber optical isolator, as set forth in claim 1 , wherein the heat sink comprises gadolinium gallium garnet.

5. The fiber optical isolator, as set forth in claim 1 , wherein the Faraday rotator comprises yttrium-iron-garnet.

6. A method of manufacturing a fiber optic isolator, the method comprising:

coupling a Faraday rotator to a heat sink, wherein the heat sink is configured to dissipate heat generated in the Faraday rotator by a light signal; and

aligning an input fiber with a collimating lens so that insertion loss decreases as a power level of the light signal increases at power levels less than 2 watts.

7. The method, as set forth in claim 6 , comprising coupling a polarizer to the Faraday rotator.

8. The method, as set forth in claim 6 , comprising aligning the input fiber and an output fiber of the fiber optic isolator to generally minimize the insertion loss of the fiber optic isolator for a light power of approximately 10 watts.

9. The method, as set forth in claim 6 , comprising installing another Faraday rotator and another heat sink inside the fiber optic isolator.

10. The method, as set forth in claim 6 , wherein coupling a Faraday rotator to the heat sink comprises constructing a Bismuth doped yttrium-iron-garnet crystal grown on a gadolinium gallium garnet substrate.

11. A fiber optic component comprising:

an optical isolator;

an input port coupled to the optical isolator and configured to receive a light beam; and

an output port coupled to the optical isolator and aligned with the optical isolator such that the insertion loss generated by the fiber optic component will decrease as a light power of the light beam increases until a minimum value of insertion loss is reached at a light power of at least 2 watts.

12. The fiber optic component, as set forth in claim 11 , wherein the output port is aligned such that the insertion loss will decrease as the light power rises until a minimum value of insertion loss is reached at an light power of at least 10 watts.

13. The fiber optic component, as set forth in claim 11 , wherein the optical isolator comprises a Faraday rotator.

14. The fiber optic component, as set forth in claim 11 , wherein the output port is aligned to at least partially compensate for an effect of a thermal lens generated in the optical isolator.

Assignments (11)