Double mirror structure for wavelength division multiplexing with polymer waveguides

1. A wavelength filtering structure, comprising:

a first reflective surface, positioned at an end of a first waveguide section, that reflects a beam comprising a plurality of wavelengths;

a filter in the path of the reflected beam that allows a selected wavelength from the reflected beam to pass and that reflects all other wavelengths in a selected beam;

a second reflective surface, positioned adjacent to the first reflective surface and at an end of a second waveguide section, that reflects the selected beam into a core of the second waveguide section; and

an emitter configured to emit the selected wavelength through the filter, wherein the emitter is aligned with the filter.

2. The wavelength filtering structure of claim 1 , wherein the first and second reflective surfaces are formed at an angle relative to the beam path.

3. The wavelength filtering structure of claim 2 , wherein the first and second reflective surfaces are formed at an angle less than 45 degrees relative to the beam path.

4. The wavelength filtering structure of claim 1 , further comprising a photodetector configured to receive the selected wavelength that passes through the filter.

5. The wavelength filtering structure of claim 1 , wherein the emitter comprises a lens configured to orient the emitted light in a direction parallel to the existing beam.

6. The wavelength filtering structure of claim 1 , wherein the emitter is set at a non-zero lateral distance from a point of incidence on the filter where the reflected beam hits.

7. The wavelength filtering structure of claim 6 , wherein the emitted wavelength reflects from the second reflective surface to enter the second waveguide section.

8. The wavelength filtering structure of claim 1 , further comprising a focusing element at an end of the first waveguide section configured to compensate for beam divergence.

9. A wavelength division multiplexer/demultiplexer, comprising:

a plurality of filtering structures formed next to each other on a board, each transmitting a different wavelength from a beam comprising a plurality of wavelengths, each filtering structure including:

a first reflective surface, positioned at an end of a first waveguide section, that reflects the beam comprising a plurality of wavelengths, formed at an angle less than 45 degrees relative to a beam path and having a curve to compensate for beam divergence;

a filter in the path of the reflected beam that allows the selected wavelength from the reflected beam to be transmitted and that reflects all other wavelengths in a selected beam;

a second reflective surface, positioned adjacent to the first reflective surface and at an end of a second waveguide section, that reflects the selected beam to the end of the second waveguide section, formed at an angle less than 45 degrees relative to the beam path; and

an emitter configured to emit the selected wavelength through the filter, wherein the emitter is aligned with the filter.

10. A method for forming a wavelength filtering structure, comprising:

forming grooves in a waveguide to define angled surfaces in a path of the waveguide;

forming a reflective layer on the angled surfaces;

depositing cladding material on top of the waveguide and on the angled surfaces;

forming a filter layer on an active region of an opto-electronic device, which transmits a single wavelength and reflects other wavelengths used;

depositing the opto-electrical device on the cladding layer such that the filter layer is aligned with a point of incidence of a light beam reflected from the reflective layer, and such that the filter layer is aligned with an emitter configured to emit the single wavelength through the filter layer; and

electrically bonding the opto-electronic device to vias in the waveguide structure.

11. The method of claim 10 , wherein forming grooves comprises forming the angled surfaces at an angle less than 45 degrees relative to a waveguide axis.

12. The method of claim 10 , wherein the opto-electronic device comprises a photodetector configured to receive the selected wavelength that passes through the filter and wherein said step of bonding comprises bonding a surface of the electrical device having said photodetector to the cladding layer such that the photodetector is aligned with a point of incidence of a beam.

13. The method of claim 10 , wherein said step of bonding comprises bonding a surface of the electrical device having said emitter to the cladding layer such that the emitter is set to a non-zero lateral distance from a point of incidence of a beam.

14. The wavelength filtering structure of claim 1 , wherein the first reflective surface has a curve along a single axis to compensate for beam divergence in a single dimension.

15. The wavelength filtering structure of claim 1 , wherein the first waveguide section is tapered relative to a carrying width of the first waveguide section, and wherein the second waveguide section is widened relative to a carrying width of the second waveguide section.

16. The wavelength division multiplexer/demultiplexer of claim 9 , wherein the first reflective surface has a curve along a single axis to compensate for beam divergence.

17. The wavelength division multiplexer/demultiplexer of claim 9 , wherein the first waveguide section is tapered relative to a carrying width of the first waveguide section, and wherein the second waveguide section is widened relative to a carrying width of the second waveguide section.

18. The method of claim 10 , further comprising forming a waveguide having a first section that tapers and a second section that is widened relative to a carrying width of the respective waveguide sections.

19. The method of claim 10 , wherein one of the grooves is formed with a curve along a single axis of one of the angled surfaces to compensate for beam divergence.