Thin film lithium niobate optical device having an engineered substrate for heterogeneous integration
An electro-optic device is described. The electro-optic device includes a substrate, an insulator on the substrate, an optical structure on the insulator and an electrode proximate to at least a portion of the optical structure. The substrate includes a trench region having a plurality of trenches therein. The trench region has an effective microwave index based on a substrate material and the plurality of trenches. The insulator is on the substrate. The optical structure is on the insulator. The optical structure has a thin film electro-optic layer including lithium. The electrode is proximate to a portion of the optical structure.
1. An electro-optic device, comprising:
a substrate including a trench region having a plurality of trenches therein, the trench region having an effective microwave index based on a substrate material and the plurality of trenches, wherein the plurality of trenches include a first row of trenches and a second row of trenches, and wherein the first row of trenches and the second row of trenches are non-intersecting;
an insulator on the substrate;
an optical structure on the insulator, the optical structure having a thin film electro-optic layer including lithium; and
an electrode proximate to a portion of the optical structure, wherein the electrode forms a grating in plan view, wherein the grating includes a plurality of chambers, wherein at least one chamber of the plurality of chambers is not completely enclosed in plan view, and wherein the at least one chamber surrounds at least one trench in plan view, and wherein the electro-optic device includes one or more of the following:
a fill that partially fills at least one trench of the plurality of trenches;
the first trench having a different length than the second trench;
the plurality of trenches not extending through the insulator;
an additional insulator being provided on the insulator; and/or
the plurality of trenches being disposed between the electrode and the optical structure and also extending under the optical structure, wherein an opening of a trench of the plurality of trenches has an oval shaped footprint.
2. The electro-optic device of claim 1 , wherein the electrode is configured to carry an electrode signal having a microwave frequency and wherein the plurality of trenches has a periodicity smaller than half of a wavelength corresponding to the microwave frequency.
3. The electro-optic device of claim 1 , wherein the plurality of trenches has a periodicity not exceeding fifty micrometers.
4. The electro-optic device of claim 1 , wherein each of the plurality of trenches has a width not exceeding twenty micrometers.
5. The electro-optic device of claim 1 , wherein each of the plurality of trenches has a height not exceeding twenty micrometers and not less than three micrometers.
6. The electro-optic device of claim 1 , wherein the plurality of trenches has the fill including at least one of a vacuum or an insulating cladding, the effective microwave index corresponding to the substrate material and the fill.
7. The electro-optic device of claim 1 , wherein the insulator does not exceed three micrometers in thickness.
8. The electro-optic device of claim 1 , wherein a portion of the plurality of trenches are under a portion of the electrode.
9. The electro-optic device of claim 1 , further comprising:
a photonics structure between the optical structure and the plurality of trenches.
10. The electro-optic device of claim 8 , wherein the photonics structure includes a silicon photonics waveguide.
11. The electro-optic device of claim 1 , wherein the effective microwave index is less than 2.5.
12. An integrated electro-optic device, comprising:
a substrate including a trench region having a plurality of trenches therein, the trench region having an effective microwave index based on a substrate material and the plurality of trenches, wherein the plurality of trenches include a first row of trenches and a second row of trenches, and wherein the first row of trenches and the second row of trenches are non-intersecting;
an insulator on the substrate;
a first optical structure on the substrate including a first photonics material; and
a second optical structure on the substrate and including a thin film electro-optic layer including lithium,
an electrode proximate to a portion of the first optical structure, wherein the electrode forms a grating in plan view, wherein the grating includes a plurality of chambers, wherein at least one chamber of the plurality of chambers is not completely enclosed in plan view, and wherein the at least one chamber surrounds at least one trench in plan view, and wherein the integrated electro-optic device includes one or more of the following:
a fill that partially fills at least one trench of the plurality of trenches;
the first trench having a different length than the second trench;
the plurality of trenches not extending through the insulator;
an additional insulator being provided on the insulator; and/or
the plurality of trenches being disposed between the electrode and the first optical structure and also extending under the first optical structure, wherein an opening of a trench of the plurality of trenches has an oval shaped footprint.
13. The integrated electro-optic device of claim 12 , wherein the first optical structure is a silicon photonics optical structure.
14. The integrated electro-optic device of claim 13 , wherein the insulator has a thickness not exceeding three micrometers, the first optical structure being on the insulator and between the second optical structure and the insulator.
15. A method, comprising:
providing a plurality of trenches in a trench region of a substrate, the trench region having an effective microwave index based on a substrate material and the plurality of trenches, wherein the plurality of trenches include a first row of trenches and a second row of trenches, and wherein the first row of trenches and the second row of trenches are non-intersecting;
providing an insulator on the substrate;
providing an optical structure on the insulator, the optical structure having a thin film electro-optic layer including lithium; and
providing an electrode proximate to a portion of the optical structure, wherein the electrode forms a grating in plan view, wherein the grating includes a plurality of chambers, wherein at least one chamber of the plurality of chambers is not completely enclosed in plan view, and wherein the at least one chamber surrounds at least one trench in plan view, and wherein the method includes one or more of the following:
a fill that partially fills at least one trench of the plurality of trenches;
the first trench having a different length than the second trench;
the plurality of trenches not extending through the insulator;
an additional insulator being provided on the insulator; and/or
the plurality of trenches being disposed between the electrode and the optical structure and also extending under the optical structure, wherein an opening of a trench of the plurality of trenches has an oval shaped footprint.
16. The method of claim 15 , wherein the providing the plurality of trenches further includes:
etching the plurality of trenches into the substrate; and wherein the providing the insulator further includes
cladding the substrate with an insulating layer; and
planarizing the insulating layer.
17. The method of claim 16 , wherein the cladding is performed before the etching of the plurality of trenches.
18. The method of claim 15 , wherein the electrode is configured to carry an electrode signal having a microwave frequency and wherein the plurality of trenches has a periodicity smaller than half of a wavelength corresponding to the microwave frequency.
19. The method of claim 15 , wherein the providing the plurality of trenches further includes:
at least partially filling the plurality of trenches using the fill including at least one of a vacuum or an insulating cladding, the effective microwave index corresponding to the substrate material and the fill.
20. The method of claim 15 , wherein the effective microwave index is less than 2.5.
21. The electro-optic device of claim 1 , wherein the electro-optic device includes three or more of the following:
a fill that partially fills at least one trench of the plurality of trenches;
the first trench having a different length than the second trench;
the plurality of trenches not extending through the insulator;
an additional insulator being provided on the insulator; and/or
the plurality of trenches being disposed between the electrode and the optical structure and also extending under the optical structure.
22. The electro-optic device of claim 1 , wherein the electro-optic device includes the following:
a fill that partially fills at least one trench of the plurality of trenches;
the first trench having a different length than the second trench;
the plurality of trenches not extending through the insulator;
an additional insulator being provided on the insulator; and
the plurality of trenches being disposed between the electrode and the optical structure and also extending under the optical structure.