Device and spectrometer for quantitatively detecting carbon 14 isotope by dual-wavelength method

Patent metadata

Field	Value
Publication number	US-2024167945-A1
Application number	US-202117789497-A
Country	US
Kind code	A1
Filing date	May 13, 2021
Priority date	Mar 12, 2021
Publication date	May 23, 2024
Grant date	—

Abstract

A device and a spectrometer for quantitatively detecting carbon 14 isotope by a dual-wavelength method. Two mid-infrared lasers with different wavelengths are locked in an optical cavity of a sample chamber, to ensure the two lasers are collinear. The cavity length of the optical cavity is adjusted by a cavity length adjusting unit, to tune the mode frequency of the optical cavity, and then tune the frequencies of the two mid-infrared lasers, so that the frequencies of the two mid-infrared lasers match with different energy levels of the target isotope molecule simultaneously. After the frequencies of the mid-infrared lasers match with the energy levels of the target isotope molecule simultaneously, the target isotope molecule is excited by two mid-infrared lasers simultaneously, and the optical cavity output signal of the second mid-infrared laser passing through the optical cavity is detected.

First claim

1 . A device for quantitatively detecting carbon 14 isotope by a dual-wavelength method, wherein the device comprises: a first laser source, a second laser source, a first laser locking module, a second laser locking module, a sample chamber and a signal detecting module;
the first laser source is used to output a continuous first mid-infrared laser; the second laser source is used to output a continuous second mid-infrared laser; the wavelengths of the first mid-infrared laser and the second mid-infrared laser are different; the first laser locking module is used to lock the first mid-infrared laser in the optical cavity of the sample chamber; the second laser locking module is used to lock the second mid-infrared laser in the optical cavity of the sample chamber; the sample chamber at least comprises a cavity length adjusting unit; the cavity length adjusting unit is used to adjust the cavity length of the optical cavity, to tune the mode frequency of the optical cavity, and then tune the frequencies of the first mid-infrared laser and the second mid-infrared laser, so that the frequency of the first mid-infrared laser and the frequency of the second mid-infrared laser match with different energy levels of the target isotope molecule simultaneously; the signal detecting module is used to detect the optical cavity output signal of the second mid-infrared laser passing through the optical cavity after the laser frequencies and the energy levels of the target isotope molecule are matched simultaneously.

2 . The device according to claim 1 , wherein the tuning bandwidth of the first mid-infrared laser is greater than 1 MHz;
the tuning bandwidth of the second mid-infrared laser is greater than 1 MHz.

3 . The device according to claim 1 , wherein the first laser locking module is used to lock the first mid-infrared laser in the optical cavity of the sample chamber, comprising:
the first laser locking module is used to modulate and demodulate the frequency and phase of the first mid-infrared laser, and generate an error signal; the first laser locking module is further used to generate a negative feedback signal according to the error signal to control the frequency of the first mid-infrared laser, so that the first mid-infrared laser is locked in the optical cavity of the sample chamber; the second laser locking module is used to lock the second mid-infrared laser in the optical cavity of the sample chamber, comprising: the second laser locking module is used to modulate and demodulate the frequency and phase of the second mid-infrared laser, and generate an error signal; the second laser locking module is further used to generate a negative feedback signal according to the error signal to control the frequency of the second mid-infrared laser, so that the second mid-infrared laser is locked in the optical cavity of the sample chamber.

4 . The device according to claim 1 , wherein the first mid-infrared laser and the second mid-infrared laser are collinear in the sample chamber.

5 . The device according to claim 1 , wherein the optical cavity is a high-finesse optical cavity, and the fineness is greater than 10,000.

6 . The device according to claim 1 , wherein the cavity length adjusting unit is a piezoelectric ceramic unit.

7 . The device according to claim 1 , wherein the sample chamber further comprises a temperature control unit;
the temperature control unit is used to adjust the temperature of the optical cavity; after adjustment, the fluctuation range of the temperature of the optical cavity is less than 100 mK.

8 . The device according to claim 1 , wherein the signal detecting module comprises a detecting unit;
the detecting unit is used to detect the optical cavity output signal of the second mid-infrared laser passing through the optical cavity.

9 . The device according to claim 8 , wherein the signal detecting module further comprises: a timing control unit;
wherein the timing control unit is used to control the working states of the cavity length adjusting unit and the detecting unit.

10 . A spectrometer, wherein the spectrometer comprises the device according to any one of claim 1 .

Assignees

• Univ Science & Technology China

Inventors

• Hu Shuiming
• Cheng Cunfeng
• Tan Yandong

Classifications

• G01N21/3151 Primary

  using two sources of radiation of different wavelengths (G01N21/33 - G01N21/39 take precedence) · CPC title

• G01N21/0303

  Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment (G01N21/031 - G01N21/15 take precedence) · CPC title

• G01N21/0332

  with temperature control (control of temperature G05D23/00; cryostats F17C3/08) · CPC title

• G01N21/39 Primary

  using tunable lasers · CPC title

• G01N21/636 Primary

  using an arrangement of pump beam and probe beam; using the measurement of optical non-linear properties; (non-linear optics per se G02F1/35) · CPC title