System and method for photomixer-based heterodyne high-frequency spectrometer and receiver

Patent metadata

Field	Value
Publication number	US-12140477-B2
Application number	US-201917044486-A
Country	US
Kind code	B2
Filing date	Apr 1, 2019
Priority date	Apr 2, 2018
Publication date	Nov 12, 2024
Grant date	Nov 12, 2024

Abstract

A system for detecting high-frequency radiation that offers near-quantum-limited sensitivity, broad spectral bandwidth, and high spectral resolution while operating at room temperature. The system can include an antenna assembly configured to receive at least a high-frequency radiation and a substrate comprising a semiconductor material with a contact-semiconductor interface connected to the antenna assembly. The system also includes an optical pump configured to produce an optical beam that has a high-frequency beat frequency, the optical beam contacting the contact-semiconductor interface to create an intermediate frequency signal by combining the optical beam with the high-frequency radiation. The system further includes a detector configured to detect the intermediate frequency and generate at least one report indicating the received, high-frequency radiation.

First claim

The invention claimed is:

1. A system for detecting high-frequency radiation, the system comprising:
an antenna assembly configured to receive at least a high-frequency radiation of between 50 GHz and 10 THz, wherein the antenna assembly comprises a logarithmic spiral antenna having a negligible reactance over the 0.1-5 THz frequency range;
a substrate comprising a semiconductor material with a contact-semiconductor interface connected to the antenna assembly;
an optical pump configured to produce an optical beam that has a high-frequency beat frequency of between 0.1 THz and 2 THz, the optical beam contacting the contact-semiconductor interface to create an intermediate frequency signal in the radio frequency (RF) range by combining the optical beam with the high-frequency radiation;
a bandpass filter in electrical communication with the antenna assembly, and configured to filter the intermediate frequency; and
a detector configured to detect the filtered intermediate frequency and generate at least one report indicating the received, high-frequency radiation.

2. The system of claim 1 , further comprising a photomixer configured to cooperate with the optical pump to create the intermediate frequency signal.

3. The system of claim 2 , wherein the photomixer comprises plasmonic contact electrodes.

4. The system of claim 1 , further comprising a lens configured to focus terahertz radiation received by the antenna assembly towards the photomixer.

5. The system of claim 1 , wherein the bandpass filter has a bandwidth of 15 MHZ or narrower.

6. The system of claim 5 , wherein a bandwidth of the bandpass filter matches a linewidth of the optical pump.

7. The system of claim 1 , further comprising a low-noise amplifier in electrical communication with the antenna assembly.

8. The system of claim 1 , wherein an operating temperature of the system is between 2 mK and 1500 K.

9. The system of claim 1 , wherein the semiconductor material may include at least one of gallium arsenide, In(x)Ga(1−x)As(y)Sb(1−y), In(x)Ga(1−x)N, InP, Si, Ge, SiGe, or graphene.

10. The system of claim 1 , wherein the optical pump comprises two distributed feedback lasers, dual-wavelength lasers, or frequency-comb lasers.

11. The system of claim 1 , further comprising an anti-reflection coating positioned over the contact-semiconductor interface.

12. The system of claim 1 , wherein the received, high-frequency radiation is within a range of 50 GHz-10 THz.

13. A method for detecting high-frequency radiation, the method comprising:
receiving high-frequency radiation of between 50 GHz and 10 THz using a lens and a logarithmic spiral antenna having a negligible reactance over the 0.1-5 THz frequency range;
producing a heterodyning optical beam that has a high-frequency beat frequency of between 0.1 THz and 2 THz using an optical pump;
creating an intermediate frequency signal in the radio frequency (RF) range by combining the optical beam with the high-frequency radiation using a photomixer;
passing the intermediate frequency signal through a bandpass filter;
detecting the filtered intermediate frequency signal; and
generating a report of the high-frequency radiation from the detected filtered intermediate frequency signal.

14. The method of claim 13 , wherein the intermediate frequency signal has a frequency between 10 MHz and 50 GHz.

15. The method of claim 13 , wherein receiving high-frequency radiation comprises focusing terahertz radiation using a lens.

16. The method of claim 13 , wherein the heterodyning optical beam is produced by two distributed feedback lasers, dual-wavelength lasers, or frequency-comb lasers.

17. The method of claim 13 , further comprising passing the intermediate frequency signal through a low-noise amplifier before undergoing detection.

18. The method of claim 13 , wherein the bandpass filter has a bandwidth of 15 MHz or narrower.

19. The method of claim 13 , wherein a spectral bandwidth of the high-frequency radiation received is a function of the high-frequency beat frequency tuning range.

20. The method of claim 13 , wherein a bandwidth of the bandpass filter matches a linewidth of the heterodyning optical pump.

Assignees

• Univ California

Inventors

• Jarrahi Mona
• Wang Ning

Classifications

• H10F30/00

  Individual radiation-sensitive semiconductor devices in which radiation controls the flow of current through the devices, e.g. photodetectors · CPC title

• H01Q9/16

  with feed intermediate between the extremities of the antenna, e.g. centre-fed dipole (H01Q9/44 takes precedence) · CPC title

• G01J3/4338 Primary

  Frequency modulated spectrometry · CPC title

• G01J3/42 Primary

  Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry (beam switching arrangements G01J3/08) · CPC title