Pixel architecture for thermal imaging system
View Patent ↗A thermally tunable pixel element includes a substrate; a thermally tunable filter island; a thermal absorption structure in direct thermal contact with and extending beyond the thermally tunable filter island; and a thermal isolation structure providing a thermally isolating path between the thermal absorption structure and the substrate.
1. A structure comprising:
a substrate;
a plurality of thermally tunable filter islands;
a thermally isolating trench between each filter island of the plurality of filter islands;
a thermal absorption structure in direct thermal contact with and extending beyond one of the thermally tunable filter islands; and
a thermal isolation structure providing a thermally isolating path between the thermal absorption structure and the substrate.
2. The structure of claim 1 , wherein the thermal absorption structure supports the said one of the filter islands from below.
3. The structure of claim 1 , wherein the thermal absorption structure supports the said one of the filter islands from above.
4. The structure of claim 1 , wherein the said one of the filter islands has a smaller area than the thermal absorption structure.
5. The structure of claim 1 , wherein the thermal isolation structure comprises a support arm for the said one of the thermally tunable filter islands and the thermal absorption structure.
6. The structure of claim 1 , wherein the thermal isolation structure comprises a plurality of support arms for the said one of the thermally tunable filter island and thermal absorption structure.
7. The structure of claim 1 , wherein the thermal isolation structure comprises a patterned portion of the thermal absorption structure.
8. The structure of claim 1 , wherein the thermal isolation structure comprises a thermally isolating post.
9. The structure of claim 1 , further including a space between the substrate and the thermal absorption structure.
10. The structure of claim 9 , wherein the space has a thickness that is about ¼ of a thermal wavelength of interest.
11. The structure of claim 10 , further comprising a patterned reflective layer that reflects at least the thermal wavelength of interest.
12. The structure of claim 1 , further comprising a patterned absorbing layer, at least a portion of which absorbs light irradiating the pixel element.
13. The structure of claim 12 , wherein the patterned absorbing layer comprises an aperture that transmits light irradiating the pixel element.
14. The structure of claim 1 , wherein the thermally tunable filter island comprises a thermally tunable thin film interference filter.
15. The structure of claim 1 , wherein the thermal absorbing structure comprises silicon dioxide, silicon nitride, or a mixture thereof.
16. The structure of claim 1 , wherein the thermal absorbing structure comprises a thin metal film.