Claims
- 1. An optical device comprising:
an optical path characterized by a refractive index, for propagating a light signal; an optical modifying element disposed in the optical path for modifying the light signal; and an overclad liquid having a refractive index less than the refractive index of the optical path disposed between the optical path and the optical modifying element for reducing optical loss of the light signal.
- 2. The optical device of claim 1 wherein the optical path comprises a waveguide.
- 3. The optical device of claim 2 wherein the overclad liquid has the refractive index lower than the waveguide.
- 4. The optical device of claim 1 wherein the optical path comprises a waveguide core.
- 5. The optical device of claim 1 wherein the optical path comprises a waveguide having a core layer disposed on top of a substrate.
- 6. The optical device of claim 5 wherein the overclad liquid has the refractive index less than the core layer.
- 7. The optical device of claim 1 further comprising a cover for enclosing the overclad liquid within the optical path.
- 8. The optical device of claim 1 wherein the optical path comprises a waveguide circuit.
- 9. An optical device comprising:
an optical planar substrate; a waveguide core having a refractive index, the waveguide core disposed on the optical planar substrate for providing an optical path for propagating a light signal; an optical modifying element optically coupled to the waveguide core for modifying the light signal; and an overclad liquid having a refractive index less than the refractive index of the waveguide core disposed between the waveguide core and the optical modifying element for reducing optical loss of the light signal.
- 10. An optical device comprising:
a planar substrate; a layer of waveguide material deposited on the planar substrate, the layer of waveguide material having a waveguide circuit etched into the waveguide material; a cover for selectively encapsulating the substrate around the waveguide circuit while leaving space to provide a gap above the waveguide circuit; and a liquid material having a lower index of refraction than the waveguide material filled into the gap above the waveguide circuit such that the liquid acts as an overclad for the waveguide circuit.
- 11. A method for fabricating a planar optical device, the method comprising the following steps:
providing a planar substrate; depositing a layer of waveguide material onto the planar substrate; etching a waveguide circuit into the waveguide material; encapsulating the substrate around the waveguide circuit to provide a gap above the waveguide circuit; and filling the gap above the waveguide circuit with a liquid material having a lower index of refraction than the waveguide material such that the liquid acts as an overclad for the waveguide circuit.
- 12. The method of claim 11 wherein the encapsulating step comprises the following steps:
depositing a solid overclad material layer on the waveguide material; forming an opposed pair of overclad sidewalls at opposed edges of the planar substrate by removing the solid overclad layer from the waveguide material away from the opposed edges of the planar substrate; mounting a cover on top of the opposed pair of overclad sidewalls for covering the planar substrate.
- 13. The method of claim 11 wherein the encapsulating step comprises the following steps:
selectively depositing a solid overclad material layer on the waveguide material and forming an opposed pair of overclad sidewalls at opposed edges of the planar substrate by removing the solid overclad layer from the waveguide material away from the opposed edges of the planar substrate in a single selective deposition step; and mounting a cover on top of the opposed pair of overclad sidewalls for covering the planar substrate.
- 14. The method of claim 11 further comprising inserting an optical modifying element disposed in the waveguide circuit for modifying a light signal.
- 15. The method of claim 14 wherein the inserting step comprises inserting a MEMS mirror of a MEMS substrate in the waveguide circuit for modifying the light signal.
- 16. The method of claim 15 further comprising the following steps:
etching a trench in the waveguide circuit such that the light signal follows a reflected optical path if the MEMS mirror is in a reflected state in the trench; forming at least one flip-chip solder bump on the planar substrate on opposed sides of the trench; and flip-chip attaching the MEMS substrate on top of the flip-chip solder bumps wherein the MEMS mirror is slidable within the trench for covering a major portion of the trench.
- 17. The method of claim 16 wherein the etching step comprises providing access to the waveguide material by etching a trench through the waveguide circuit.
- 18. The method of claim 17 wherein the encapsulating step comprises the following steps:
selectively depositing a solid overclad material layer on the waveguide material; forming an opposed pair of overclad sidewalls at opposed edges of the planar substrate by removing the solid overclad layer from the waveguide material away from the trench and away from the opposed edges of the planar substrate; and sealing the MEMS substrate to the opposed pair of overclad sidewalls as a cover for covering the planar substrate.
- 19. The method of claim 17 wherein the encapsulating step comprises the following steps:
pigtailing on opposed edges of the planar substrate for forming an opposed pair of pigtail blocks; and enclosing the MEMS substrate with a cover sealed to the opposed pair of pigtail blocks as a cover for enclosing the planar substrate.
- 20. The method of claim 11 wherein the filling step comprises filling the gap with the liquid material having a fluorinated compound.
Priority Claims (1)
Number |
Date |
Country |
Kind |
00400816.5 |
Mar 2000 |
EP |
|
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of European Application No. 00400816.5, filed Mar. 23, 2000.