Optical interleaver
View Patent ↗In accordance with an exemplary embodiment of the present invention, an optical device includes a first element which decomposes said optical signal into a first beam and a second beam with the first beam being in a first polarization state and the second beam being in a second polarization state. The first and second polarization states being orthogonal to one another and including each of said multiple channels. The optical device further includes a second element which transforms the first beam into a first elliptically polarized state having odd channels in a third polarization state and even channels in a fourth polarization state having even channels in the third polarization state and odd channels in the fourth polarization state; and a third element which combines the odd channels into a first output port and the even channels into a second output port.
1. An apparatus for optical interleaving/de-interleaving, comprising:
an input port for receiving an optical signal, said optical signal being polarized light and having multiple channels;
a first element for decomposing said optical signal into a first beam and a second beam, said first beam being in a first polarization state and said second beam being in a second polarization state, said first and said second polarization states being orthogonal to one another and including each of said multiple channels;
a second element for transforming said first beam into a first elliptically polarized state having odd channels in a third polarization state and even channels in a fourth polarization state, and said second element transforming said second beam into a second elliptically polarized state having even channels in said third polarization state and odd channels in said fourth polarization state;
a first passive element thermally coupled to the second element and configured to compensate for thermal effects on the second element; and
a third element for combining said odd channels into a first output port and said even channels into a second output port.
2. An apparatus as recited in claim 1 , wherein said multiple channels have a channel spacing of (1/(2τ)) and said odd channels have a channel spacing of (1/τ) and said even channels have a channel spacing of (1/τ).
3. An apparatus as recited in claim 2 , wherein (1/(2τ)) is 400 GHz.
4. An apparatus as recited in claim 2 , wherein (1/(2ρ)) is 200 GHz.
5. An apparatus as recited in claim 2 , wherein (1/(2τ)) is 100 GHz.
6. An apparatus as recited in claim 2 , wherein (1/(2τ)) is 50 GHz.
7. An apparatus as recited in claim 2 , wherein (1/(2τ)) is 25 GHz.
8. An apparatus as recited in claim 2 , wherein (1/(2τ)) is 12.5 GHz.
9. An apparatus as recited in claim 1 , wherein the first output port is concatenated with a second apparatus and the second output port is concatenated with a third apparatus, the second apparatus for separating the odd channels into first and second sub-signals, the third apparatus for separating the even channels into third and fourth sub-signals, each sub-signal having a channel spacing of (2/τ).
10. An apparatus as recited in claim 1 , wherein said second element is a birefringent material.
11. An apparatus as recited in claim 1 , wherein said first element is a polarization splitter.
12. An apparatus as recited in claim 1 , wherein said optical signal is elliptically polarized.
13. An apparatus as recited in claim 1 , wherein said third element includes a polarization splitter.
14. An apparatus as recited in claim 1 , wherein said third element further includes a half-wave plate and a birefringent element.
15. An apparatus recited in claim 1 , further comprising a second passive element thermally coupled to the first passive element and configured to compensate for second-order thermal effects.
16. An apparatus for interleaving/de-interleaving optical signals, comprising:
input port for receiving an elliptically polarized optical signal;
a polarization splitter for splitting said elliptically polarized optical signal into a first beam being in a first polarization state and a second beam being in a second polarization state, said first and second polarization states being mutually orthogonal;
a birefringent element for transforming said first beam into a first elliptically polarized state having odd channels in a third polarization state and even channels in a fourth polarization state, and said birefringent element transforming said second beam into a second elliptically polarized state having even channels in said third polarization state and odd channels in said fourth polarization state;
a first passive element thermally coupled to the birefringent element and configured to compensate for thermal effects on the birefringent element; and
a combining element for combining said odd channels into a first output port and said even channels at a second output port.
17. An apparatus as recited in claim 16 , wherein said optical signal includes multiple channels having a first channel spacing, and said odd channels and said even channels each have a second channel spacing, wherein said second channel spacing is twice said first channel spacing.
18. An apparatus as recited in claim 17 , wherein said first channel spacing is 400 GHz.
19. An apparatus as recited in claim 17 , wherein said first channel spacing is 200 GHz.
20. An apparatus as recited in claim 17 , wherein said first channel spacing is 100 GHz.
21. An apparatus as recited in claim 17 , wherein first channel spacing is 50 GHz.
22. An apparatus as recited in claim 17 , wherein first channel spacing is 25 GHz.
23. An apparatus as recited in claim 17 , wherein first channel spacing is 12.5 GHz.
24. An apparatus as recited in claim 17 , wherein said combining element includes a half wave plate and a polarization splitter.
25. An apparatus as recited in claim 16 , wherein said birefringent element is chosen from the group consisting essentially of electro-optic devices, birefringent crystals and birefringent optical fibers.
26. An apparatus as recited in claim 16 , wherein said birefringent element has a o-axis (optic axis) oriented at 45° to said first and said second polarization states.
27. An apparatus recited in claim 16 , further comprising a second passive element thermally coupled to the first passive element and configured to compensate for second-order thermal effects.
28. A method of interleaving/de-interleaving an optical signal, the method comprising:
providing an optical signal to an input port, said optical signal being polarized light and including multiple channels;
decomposing said optical signals into a first beam and a second beam said first beam being in a first polarization state and said second beam being in a second polarization state, said first and said second polarization states being orthogonal to one another and including each of said multiple channels;
transforming said first beam into a first elliptically polarized state having odd channels in a third polarization state and even channels in a fourth polarization state and transforming said second beam into a second elliptically polarized state having even channels in said third polarization stale and odd channels in said fourth polarization state;
passively compensating for temperature induced wavelength drift; and combining said odd channels into a first output port and said even channels into a second output port.
29. A method as recited in claim 28 , wherein said multiple channels have a channels spacing of (1/(2τ)) and said odd channels have a spacing of (1/(2τ) and said even channels have a spacing of (1/(τ).
30. A method as recited in claim 29 , wherein (1/(2τ)) is 400 GHz.
31. A method as recited in claim 29 , wherein (1/(2τ)) is 200 GHz.
32. A method as recited in claim 29 , wherein (1/(2τ)) is 100 GHz.
33. A method as recited in claim 29 , wherein (1/(2ρ)) is 50 GHz.
34. A method as recited in claim 29 , wherein (1/(2τ)) is 25 GHz.
35. A method as recited in claim 29 , wherein (1/(2τ)) is 12.5 GHz.
36. A method as recited in claim 28 , wherein the method further comprises: providing said odd channels and said even channels to a concatenated second interleaver/deinterleaver and a concatenated third interleaver/deinterleaver, respectively, and said even and said odd channels are selectively output from said second and said third interleavers/deinterleavers having a channel spacing (2/τ).
37. A method recited in claim 28 , further comprising the step of passively compensating for second-order thermal effects.