Photodetector capable of detecting long wavelength radiation

1. A photodetector capable of detecting long wavelength radiation, comprising:

a source disposed on a proximal end of an insulation layer;

a drain disposed on a distal end of the insulation layer;

at least one nano-assembly coupling the source and the drain between the proximal and distal ends; and

at least two surface plasmon waveguides positioned between the source and the drain and juxtaposed to the at least one nano-assembly in a longitudinal direction of the at least one nano-assembly to receive photons from incident light and to confine at least a portion of the photons around at least a portion of the nano-assembly,

wherein one of the at least two surface plasmon waveguides is positioned along a first side of the at least one nano-assembly, and another of the at least two surface plasmon waveguides is positioned along a second side of the at least one nano-assembly that is opposite the first side.

2. The photodetector of claim 1 , wherein at least one of the at least two surface plasmon waveguides is in contact with the at least one nano-assembly.

3. The photodetector of claim 1 , wherein at least one of the at least two surface plasmon waveguides is spaced-apart from the at least one nano-assembly by several to thousands of nanometers.

4. The photodetector of claim 1 , wherein the nano-assembly is configured to have at least one intersubband such that at least one transition of electrons in the at least one intersubband corresponds to detection of a photon.

5. The photodetector of claim 4 , wherein the photon has energy in a range from about several meV to hundreds of meV.

6. The photodetector of claim 1 , wherein a plurality of waveguides and nano-assemblies are disposed so that at least some of the waveguides are interposed between the nano-assemblies to create an alternating arrangement of the waveguides and the nano-assembly.

7. The photodetector of claim 1 , wherein the source and the drain are spaced-apart from each other.

8. The photodetector of claim 1 , wherein the at least one nano-assembly includes at least one of a nanowire, a nanobelt, or a nanorod.

9. The photodetector of claim 1 , wherein the at least one nano-assembly includes an array of at least one of a nano-wire, a nanobelt, or a nanorod.

10. The photodetector of claim 1 , wherein the at least one nano-assembly is selected from the group consisting of ZnO, Si, and InAs.

11. The photodetector of claim 10 , wherein each of the at least one nano-assembly is fabricated from the same material as each other.

12. The photodetector of claim 1 , wherein each of the at least one nano-assembly is fabricated from different types of material.

13. The photodetector of claim 1 , wherein at least one of the at least two surface plasmon waveguides is fabricated from a metal material.

14. The photodetector of claim 13 , wherein the metal material is Ag.

15. The photodetector of claim 1 , wherein the long wavelength radiation has a wavelength of at least 1 μm.

16. The photodetector of claim 1 , wherein the at least one nano-assembly has a width from about 10 nm to about 500 nm.

17. The photodetector of claim 1 , wherein the at least one nano-assembly has a length from about 0.5 μm to about 5 μm.