Detecting system based on terahertz wave

Patent metadata

Field	Value
Publication number	US-9852871-B1
Application number	US-201715497940-A
Country	US
Kind code	B1
Filing date	Apr 26, 2017
Priority date	Jun 3, 2016
Publication date	Dec 26, 2017
Grant date	Dec 26, 2017

Abstract

The disclosure relates to a detecting system including a terahertz wave source, a detector and a controlling computer. The terahertz wave source includes a terahertz reflection klystron including an electron emission unit, a resonance unit, an output unit. The electron emission unit is configured to emit electrons. The resonance unit includes a resonant cavity communicated with the electron emission unit so that the electron emission unit emit electrons into the resonant cavity. The resonant cavity of the electron emission unit opposite the cavity wall has an output aperture coupled. The output unit is communicated with the resonance unit by the output aperture coupled. The resonance unit generate terahertz wave transmit to the output unit by the output aperture coupled.

First claim

What is claimed is:

1. A detecting system based on terahertz wave, comprising:
a terahertz wave source, wherein the terahertz wave source comprises a terahertz reflex klystron, and the terahertz reflex klystron comprises:
an electron emission unit being configured to emit a plurality of electrons, the electron emission unit defining a first opening;
a resonant unit comprising a resonant cavity frame defining a resonant cavity, the resonant cavity frame comprising a top wall and a bottom wall, the top wall and the bottom wall face each other; and the bottom wall comprising a bottom opening, the top wall comprising a top opening and at least one outputting hole, and the bottom opening and the first opening are aligned with each other; and
an output unit being configured to output the terahertz wave, and the plurality of electrons being transferred to the output unit from the at least one outputting hole;

a detector spaced from the terahertz wave source; and
a controlling computer connected to both the terahertz wave source and the detector.

2. The detecting system of claim 1 , wherein the first opening, the bottom opening and the top opening are co-axial.

3. The detecting system of claim 1 , wherein the at least one outputting hole comprises a plurality of outputting holes arranged orderly, and the plurality of outputting holes are central symmetry around a center of the top opening.

4. The detecting system of claim 1 , wherein the electron emission unit comprises a cathode, an electron emitter unit, an electron injection layer, and an electron extraction grid; and the electron emitter unit is electrically connected to the cathode, the electron injection layer defines a hollow space having the first opening, the electron emitter unit is located in the hollow space, and the electron extraction grid covers the first opening.

5. The detecting system of claim 4 , wherein the electron emission unit further comprises an insulating layer located on a surface of the electron injection layer; and the insulating layer comprises two potions, a first portion of the insulating layer is located between the electron injection layer and the cathode, and a second portion of the insulating layer is located in the hollow space and on an inside surface of the electron injection layer.

6. The detecting system of claim 4 , wherein the hollow space is in a shape of inverted funnel, and a size of the hollow space is gradually narrowed along a direction away from the cathode.

7. The detecting system of claim 4 , wherein the electron emitter unit is in a tapered shape with a peak and comprises a plurality of electron emitters, and one of the plurality of electron emitters, that is in a center of the electron emitter unit, is the highest.

8. The detecting system of claim 7 , wherein a height of each of the plurality of electron emitters is gradually decreased along a direction away from the center.

9. The detecting system of claim 4 , wherein the electron emitter unit is a carbon nanotube wire comprising a plurality of carbon nanotubes parallel with each other or twisted with other.

10. The detecting system of claim 4 , wherein the electron extraction grid is a carbon nanotube composite layer, a carbon nanotube layer, or a graphene layer.

11. The detecting system of claim 4 , wherein the electron extraction grid comprises a carbon nanotube layer and a coating layer, and the carbon nanotube layer defines a plurality of apertures.

12. The detecting system of claim 1 , wherein the resonant unit further comprises an insulating support, a first grid electrode, a second grid electrode, a reflective room and a reflective electrode; the insulating support is located around the bottom opening; the first grid electrode is located on the insulating support; the second grid electrode covers the top opening; the reflective room covers the top opening and open to the top opening; and the reflective electrode is located in the reflective room.

13. The detecting system of claim 12 , wherein the reflective electrode is located above and faces the second grid electrode.

14. The detecting system of claim 1 , wherein two detectors are located on opposite two sides of the terahertz wave source.

15. The detecting system of claim 14 , wherein an angle between a receiving surface of each of the two detectors and a outputting surface of the terahertz wave source is greater than 90 degrees and less than 180 degrees.

16. The detecting system of claim 15 , wherein an angle is in arrange from about 120 degrees to about 160 degrees.

17. A detecting system based on terahertz wave, comprising:
a terahertz wave source, wherein the terahertz wave source comprises:
a substrate;
a plurality of first electrodes and a plurality of second electrodes located on the substrate; and
a plurality of terahertz reflex klystrons electrically connected to the plurality of first electrodes and the plurality of second electrodes, wherein each of the plurality of terahertz reflex klystrons comprises:
an electron emission unit being configured to emit a plurality of electrons, the electron emission unit defining a first opening;
a resonant unit comprising a resonant cavity frame defining a resonant cavity, the resonant cavity frame comprising a top wall and a bottom wall, the top wall and the bottom wall facing each other; and the bottom wall comprising a bottom opening, the top wall comprising a top opening and at least one outputting hole, and the bottom opening and the first opening are aligned with each other; and
an output unit being configured to output the terahertz wave, and the plurality of electrons being transferred to the output unit from the at least one outputting hole;

a detector spaced from the terahertz wave source; and
a controlling computer connected to both the terahertz wave source and the detector.

18. The detecting system of claim 17 , wherein the plurality of first electrodes and the plurality of second electrodes are perpendicular with each other to from a grid structure.

19. The detecting system of claim 18 , wherein the grid structure comprises a plurality of cells, and each of the plurality of terahertz reflex klystrons is located in the one of the plurality of cells and electrically connected to one of the plurality of first electrodes and one of the plurality of second electrodes.

20. The detecting system of claim 17 , wherein two detectors are located on opposite two sides of the terahertz wave source, and an angle between a receiving surface of each of the two detectors and a outputting surface of the terahertz wave source is greater than 90 degrees and less than 180 degrees.

Assignees

• Univ Tsinghua
• Hon Hai Prec Ind Co Ltd

Inventors

• Liu Peng
• Chen Pi-Jin
• Li Zong-Qian
• Lei You-Hua
• Zhang chun-hai
• Zhou Duan-Liang
• Fan Shou-Shan

Classifications

• H01J25/22

  Reflex klystrons, i.e. tubes having one or more resonators, with a single reflection of the electron stream, and in which the stream is modulated mainly by velocity in the modulator zone · CPC title

• H01J31/127

  using large area or array sources, i.e. essentially a source for each pixel group · CPC title

• H01J25/26 Primary

  in which the electron stream is coaxial with the axis of the resonator or resonators and is tube-like before reflection · CPC title

• H01J23/04

  Cathodes · CPC title

• H01J3/021

  Electron guns using a field emission, photo emission, or secondary emission electron source · CPC title