Optical components with one or more embedded Bragg reflectors and tapered waveguide cores
Structures for an optical component, such as an optical reflector or an Echelle grating, and methods of forming such structures. The structure comprises a first waveguide core positioned in a vertical direction over a semiconductor substrate. The first waveguide core includes a tapered section and a plurality of segments separated by a plurality of gaps. A second waveguide core, which is positioned in the vertical direction relative to the first waveguide core, includes a portion positioned adjacent to the first waveguide core.
1. A structure for an optical reflector, the structure comprising:
a semiconductor substrate;
a first waveguide core positioned in a vertical direction over the semiconductor substrate, the first waveguide core including a first tapered section and a first plurality of segments separated by a first plurality of gaps; and
a second waveguide core positioned in the vertical direction relative to the first waveguide core, the second waveguide core including a portion positioned adjacent to the first waveguide core.
2. The structure of claim 1 further comprising:
a third waveguide core positioned in the vertical direction over the semiconductor substrate and adjacent to the portion of the second waveguide core, the third waveguide core including a second tapered section and a second plurality of segments separated by a second plurality of gaps.
3. The structure of claim 2 wherein the portion of the second waveguide core is positioned in a lateral direction between the first waveguide core and the third waveguide core.
4. The structure of claim 3 wherein the first waveguide core and the third waveguide core comprise polysilicon, amorphous silicon, or single-crystal silicon, and the second waveguide core comprises silicon nitride.
5. The structure of claim 2 wherein the portion of the second waveguide core is positioned in the vertical direction between the first waveguide core and the third waveguide core.
6. The structure of claim 5 wherein the first waveguide core comprises single-crystal silicon, the second waveguide core comprises silicon nitride, and the third waveguide core comprises polysilicon or amorphous silicon.
7. The structure of claim 1 wherein the first waveguide core comprises single-crystal silicon, and the second waveguide core comprises silicon nitride.
8. The structure of claim 1 wherein the first waveguide core comprises polysilicon or amorphous silicon, and the second waveguide core comprises silicon nitride.
9. The structure of claim 1 wherein the second waveguide core is positioned in an overlapping arrangement with the first tapered section and the first plurality of segments of the first waveguide core.
10. The structure of claim 1 wherein the second waveguide core includes an end surface and a tapered section that terminates at the end surface, and the first tapered section of the first waveguide core is positioned adjacent to the tapered section of the second waveguide core.
11. The structure of claim 10 wherein the tapered section of the second waveguide core is longitudinally offset from the first plurality of segments of the first waveguide core.
12. The structure of claim 1 further comprising:
a dielectric layer over the first waveguide core, the dielectric layer comprising a dielectric material, and the dielectric material of the dielectric layer disposed in the first plurality of gaps of the first waveguide core.
13. The structure of claim 1 wherein the first tapered section of the first waveguide core is configured to receive light transferred from the second waveguide core, and the first plurality of segments of the first waveguide core are configured to reflect the light back to the first tapered section of the first waveguide core for transfer to the second waveguide core.
14. A method of forming a structure for an optical reflector, the method comprising:
forming a first waveguide core positioned in a vertical direction over a semiconductor substrate, wherein the first waveguide core includes a tapered section and a plurality of segments separated by a plurality of gaps; and
forming a second waveguide core positioned in the vertical direction relative to the first waveguide core, wherein the second waveguide core includes a portion positioned adjacent to the first waveguide core.