Room-temperature quantum noise limited spectrometry and methods of the same

1. A heterodyne detection system for detecting light, comprising:

a first input aperture configured to receive first light from a scene input;

a second input aperture configured to receive second light from a local oscillator input;

a broadband local oscillator configured to provide the second light to the second input aperture;

a dispersive element configured to disperse the first light and the second light; and

a final condensing lens coupled to a detector;

a radio frequency (RF) waveguide, wherein the RF waveguide is coplanar to the detector;

wherein the final condensing lens is configured to concentrate incident light from a primary condensing lens onto the detector;

wherein the detector is configured to sense a frequency difference between the first light and the second light;

wherein the final condensing lens comprises a plasmonic condensing lens;

wherein the first input aperture is spatially offset from the second input aperture; and

wherein the first input aperture and the second input aperture are arranged such that the first and second light pass through the first and second input apertures in a same direction relative to each other.

2. The heterodyne detection system as recited in claim 1 , wherein the detector is an infrared detector.

3. The heterodyne detection system as recited in claim 1 , wherein the detector comprises a type II InAs/GaSb superlattice.

4. The heterodyne detection system as recited in claim 1 , wherein the detector comprises InAs/GaAs;

wherein the detector comprises a lattice of the InAs/GaAs; and

wherein the lattice is characterized by a lattice period of about 58 A.

5. The heterodyne detection system as recited in claim 1 , further comprising an electro-optic modulator coupled to the RF waveguide.

6. The heterodyne detection system as recited in claim 5 , further comprising a bandpass filter coupled to the electro-optic modulator.

7. The heterodyne detection system as recited in claim 1 , wherein the detector comprises a photodetector array.

8. The heterodyne detection system as recited in claim 1 , wherein the detector comprises a quantum dot detector.

9. The heterodyne detection system as recited in claim 1 , wherein the plasmonic condensing lens is a plasmonic infrared (IR) condensing lens.

10. The heterodyne detection system as recited in claim 1 , wherein the plasmonic condensing lens is placed in contact with the detector.

11. The heterodyne detection system as recited in claim 1 , wherein the plasmonic condensing lens comprises an immersion micro-lens.

12. The heterodyne detection system as recited in claim 1 , wherein the plasmonic condensing lens is characterized by a conical geometry.

13. The heterodyne detection system as recited in claim 1 , wherein the plasmonic condensing lens comprises a Si core having a conductive metal cladding on radial surfaces thereof.

14. The heterodyne detection system as recited in claim 13 , wherein the conductive metal comprises Pt.

15. The heterodyne detection system as recited in claim 1 , wherein the plasmonic condensing lens is characterized by dimensions including a length of approximately 10 μm, a receiving end diameter of approximately 3.5 μm, and a transmitting end diameter of approximately 0.5 μm.

16. The heterodyne detection system as recited in claim 1 , wherein an angle measured from perpendicular to a planar surface of the detector and a sidewall of the plasmonic condensing lens is in a range from about 5° to about 12°.

17. The heterodyne detection system as recited in claim 16 , wherein the angle measured from perpendicular to the planar surface of the detector and the sidewall of the final condensing lens is about 8.5°.

18. A method of forming a plasmonic condensing lens for room temperature quantum noise limited (QNL) infrared (IR) spectrometry using a heterodyne detection system as recited in claim 1 , the method comprising:

forming a silicon cone on a substrate;

coating the silicon cone with a highly reflective material selected from a group consisting of Au, Ag, Pt and Cu; and

modifying the silicon cone using focused ion beam (FIB) modification to permit transmittance of light through the silicon cone.

19. A heterodyne detection system for detecting light, comprising:

a first input aperture configured to receive first light from a scene input;

a second input aperture configured to receive second light from a local oscillator input;

a broadband local oscillator configured to provide the second light to the second input aperture;

a dispersive element configured to disperse the first light and the second light; and

a final condensing lens coupled to a detector;

wherein the final condensing lens is configured to concentrate incident light from a primary condensing lens onto the detector;

wherein the detector is configured to sense a frequency difference between the first light and the second light;

wherein the final condensing lens comprises a plasmonic condensing lens;

wherein the detector is a square-law detector;

wherein the first input aperture is spatially offset from the second input aperture; and

wherein the first input aperture and the second input aperture are arranged such that the first and second light pass through the first and second input apertures in a same direction relative to each other.

20. A heterodyne detection system for detecting light, comprising:

a first input aperture configured to receive first light from a scene input;

a second input aperture configured to receive second light from a local oscillator input;

a broadband local oscillator configured to provide the second light to the second input aperture;

a dispersive element configured to disperse the first light and the second light; and

a final condensing lens coupled to a detector;

a radio frequency (RF) waveguide, wherein the RF waveguide is coplanar to the detector;

wherein the final condensing lens is configured to concentrate incident light from a primary condensing lens onto the detector;

wherein the detector is configured to sense a frequency difference between the first light and the second light;

wherein the final condensing lens comprises a plasmonic condensing lens;

wherein the plasmonic condensing lens is characterized by a conical geometry; and

wherein the conical geometry comprises:

a first diameter at a distal end adjacent the detector, the first diameter having a length of less than about one-half wavelength of the incident light in Si, and

a second diameter at an end receiving the incident light from the dispersive element, the second diameter having a length approximately equal to a diffraction limit set by the primary condensing lens.