Optical cell with wavelength compensator

1. An optical cell comprising:

a splitter configured to split a light beam into first and second components and direct the first component into a first optical path having a first optical path length and the second component into a second optical path having a second optical path length;

a coupler configured to join the first and second components; and

a first compensator disposed between the splitter and the combiner in the first optical path, the first compensator rotatable about a first axis, wherein rotating the first compensator about the first axis varies a distance that the first optical path passes through the first compensator thereby changing the first optical path length.

2. The optical cell of claim 1 , wherein rotating the first compensator changes a central wavelength of an optical signal traversing the first optical path.

3. The optical cell of claim 1 , further comprising a second compensator disposed in the second optical path, the second compensator rotatable about a second axis, wherein rotating the second compensator about the second axis varies a distance that the second optical path passes through the second compensator thereby changing the second optical path length.

4. The optical cell of claim 3 , wherein the second compensator is configured to rotate independent of the first compensator.

5. The optical cell of claim 3 , wherein the second compensator is rotatable about a third axis, wherein rotating the second compensator about the third axis varies a distance that the second optical path passes through the second compensator thereby changing the second optical path length.

6. The optical cell of claim 1 , wherein the first and second optical path lengths are different.

7. The optical cell of claim 1 , further comprising at least one first optical element positioned in and defining the first optical path length of the first optical path together with the first compensator.

8. The optical cell of claim 1 , wherein the optical cell forms part of a delay line interferometer, an interleaver, or a deinterleaver.

9. The optical cell of claim 1 , wherein the first compensator is rotatable about a second axis, wherein rotating the first compensator about the second axis varies a distance that the first optical path passes through the first compensator thereby changing the first optical path length.

10. An optical cell comprising:

a first block that includes a splitter configured to split a light beam into first and second components and direct the first component into a first optical path having a first optical path length and the second component into a second optical path having a second optical path length;

a second block positioned within the first and second optical paths and that includes a coupler configured to join the first and second components into an output beam; and

a first compensator disposed in the first optical path between the splitter and the coupler and positioned to receive the first component from the splitter, the first compensator rotatable about a first axis, wherein rotating the first compensator about the first axis varies a distance that the first optical path and the first component passes through the first compensator thereby changing the first optical path length.

11. The optical cell of claim 10 , further comprising a second compensator disposed in the second optical path, the second compensator rotatable about a second axis, wherein rotating the second compensator about the second axis varies a distance that the second optical path passes through the second compensator thereby changing the second optical path length.

12. The optical cell of claim 11 , further comprising a third compensator disposed in the first optical path between the first compensator and the second block, the third compensator rotatable about a third axis, wherein rotating the third compensator about the third axis varies a distance that the first optical path passes through the third compensator thereby changing the first optical path length.

13. The optical cell of claim 12 , wherein the third compensator is configured to rotate independent of the first compensator.

14. The optical cell of claim 10 , wherein the first and second components have different polarization vectors.

15. The optical cell of claim 14 , wherein the first and second components have orthogonal polarizations.

16. The optical cell of claim 10 , wherein the first and second optical paths have different physical and optical path lengths.

17. An optical cell comprising:

a splitter configured to split a light beam into first and second components;

a coupler configured to join the first and second components into an output beam; and

a compensator disposed between the splitter and the coupler and positioned to receive the first component from the splitter, the compensator rotatable about an axis, wherein rotating the compensator about the axis varies a distance that the first component passes through the compensator thereby changing a first optical path length through which the first component travels.

18. The optical cell of claim 17 , wherein the splitter is configured to direct the first component into a first optical path and the second component into a second optical path.

19. The optical cell of claim 18 , wherein the first and second optical paths have different optical path lengths.

20. The optical cell of claim 17 , wherein rotating the compensator changes a central wavelength of the first component.

21. The optical cell of claim 17 , wherein a physical path length of the first component between the splitter and the coupler remains constant when the compensator is rotated.

22. The optical cell of claim 17 , wherein the optical cell forms part of a delay line interferometer, an interleaver, or a deinterleaver.