Wavelength-selective thermal detection apparatus and methods
A wavelength selective bolometer includes a substrate configured to serve as a foundation for the apparatus and a thermal isolation gap established between the substrate and subsequent solid material layers. A conducting ground plane layer is disposed above the thermal isolation gap, and a first dielectric layer is mated to a top surface of the conducting ground plane. A temperature sensing material layer is mated to a top surface of the first dielectric layer, and a plurality of interconnects is placed in electrical communication with the temperature sensing material layer. A second dielectric layer is mated to a top surface of the temperature sensing material, and at least one conductive element is mated to a top surface of the second dielectric layer. The dimensions of the conductive element and other variables are chosen to achieve resonant absorption of selected wavelengths of radiation incident thereupon.
1. A wavelength selective bolometer apparatus, the apparatus comprising:
a substrate configured to serve as a foundation for the apparatus;
a thermal isolation gap established between the substrate and subsequent solid material layers;
a conducting ground plane layer disposed above the thermal isolation gap;
a first dielectric layer mated to a top surface of the conducting ground plane;
a temperature sensing material layer mated to a top surface of the first dielectric layer
a plurality of interconnects in electrical communication with the temperature sensing material layer, and extending beyond a perimeter of the first dielectric layer;
a second dielectric layer mated to a top surface of the temperature sensing material;
at least one conductive element mated to a top surface of the second dielectric layer; and
wherein the dimensions of the conductive element and a combined thickness of the first dielectric layer, the temperature sensing material layer, and the second dielectric layer are chosen to achieve resonant absorption of selected wavelengths of radiation incident thereupon.
2. The apparatus of claim 1 , wherein the temperature sensing layer comprises a first high temperature coefficient of resistance (TCR) material.
3. The apparatus of claim 1 , wherein the first dielectric layer and the second dielectric layer also comprise the temperature sensing material.
4. The apparatus of claim 2 , wherein the temperature sensing layer includes a second high TCR material layer in contact with the first high TCR layer.
5. The apparatus of claim 1 , wherein the first dielectric layer and the second dielectric layer are selected from the group consisting of silicon dioxide, hafnium dioxide, silicon nitride, titanium dioxide, and aluminum nitride.
6. The apparatus of claim 1 wherein each of the at least one conductive element and the conducting ground plane layer comprises material selected from the group consisting of metals, metal silicides, metal germanides, semimetals, semiconductors, conducting oxides, and conducting polymers.
7. The apparatus of claim 1 , further including a plurality of conductive elements disposed on the top side of the second dielectric layer.
8. The apparatus of claim 7 , wherein the plurality of conductive elements are disposed in a periodic or non-periodic geometric pattern.
9. The apparatus of claim 1 , wherein the at least one conducting layer comprises a a periodic or non-periodic array of holes in an otherwise continuous layer.
10. The apparatus of claim 1 , wherein the temperature sensing layer is VO x , where x has a value between 1 and 2.
11. The apparatus of claim 10 , wherein the temperature sensing layer further includes metallic nano-particles.
12. The apparatus of claim 1 , wherein the temperature sensing layer is comprised of amorphous silicon.
13. The apparatus of claim 1 , wherein the apparatus is a micro-electro-mechanical system air-bridge.