System and method for remote detection of SERS spectra

Patent metadata

Field	Value
Publication number	US-10876973-B2
Application number	US-202016745730-A
Country	US
Kind code	B2
Filing date	Jan 17, 2020
Priority date	Jan 21, 2019
Publication date	Dec 29, 2020
Grant date	Dec 29, 2020

Abstract

A remote SERS spectrum detection system and a method thereof. The system includes: a pulsed laser light source, configured to emit Raman excitation light; an optical fiber Raman coupling module, configured to couple the Raman excitation light; the optical fiber Raman probe, configured to transmit the Raman excitation light to an object to be measured to generate a SERS signal light, a backscattered SERS signal light being coupled to a monochromator through the optical fiber Raman coupling module; the monochromator, configured to split the backscattered SERS signal light, to obtain backscattered SERS signal lights at different wavelengths; a high-speed photodetector, configured to convert the backscattered SERS signal lights into time-resolved electrical signals; a processor, for analyzing electrical signals, retrieving a SERS spectrum of the remote object to be measured, and controlling automatic scanning of a grating in the monochromator to achieve clock synchronization.

First claim

What is claimed is:

1. A system for remote detection of SERS spectra, comprising:
a pulsed laser light source, configured to emit pulsed laser light, the pulsed laser light being used as a Raman excitation light;
an optical fiber Raman coupling module connected to the pulsed laser light source, configured to couple the Raman excitation light to an optical fiber SERS probe;
the optical fiber SERS probe being connected to the optical fiber Raman coupling module, configured to transmit the Raman excitation light to an object to be measured to generate a SERS signal light, the SERS signal light comprising a forward-scattered SERS signal light and a backscattered SERS signal light; the backscattered SERS signal light being returned by the optical fiber SERS probe, and coupled to a monochromator through the optical fiber Raman coupling module; the optical fiber SERS probe having an increased length to achieve remote detection of SERS spectra;
the monochromator being connected to the optical fiber Raman coupling module, configured to split the backscattered SERS signal light, to obtain backscattered SERS signal lights at different wavelengths; an optical fiber adapter being provided at an entrance slit of the monochromator, and configured for efficient coupling between the SERS signal in an output fiber and the monochromator;
a high-speed photodetector connected to the monochromator, configured to convert the backscattered SERS signal lights into time-resolved electrical signals; and
a processor connected to the pulsed laser light source, the high-speed photodetector and the monochromator, respectively, for performing time-domain analysis on the time-resolved electrical signals, removing a Raman background of the optical fiber itself by adding and averaging a plurality of Raman pulse signals, retrieving a SERS spectrum of the object to be measured at a remote detection point, and controlling output of the pulsed laser light and automatic scanning of a grating in the monochromator to achieve clock synchronization.

2. The system for remote detection of SERS spectra according to claim 1 , wherein the optical fiber Raman coupling module comprises an input fiber, an output fiber, a coupling module body and a detection end; the input and output fibers are connected to one end of the coupling module body, the other end of the coupling module body is connected to the detection end; the input fiber is connected to the pulsed laser light source; the output fiber is connected to the monochromator; and the detection end is connected to the optical fiber SERS probe.

3. The system for remote detection of SERS spectra according to claim 2 , wherein the detection end includes an FC/PC or SMA905 standard optical fiber interface.

4. A method for remote detection of SERS spectra, the method being applicable to the system for remote detection of SERS spectra according claim 3 , the method comprising:
obtaining pulsed laser light, the pulsed laser light being a Raman excitation light;
detecting an object to be measured by using the Raman excitation light, to obtain a backscattered SERS signal light;
splitting the backscattered SERS signal light, to obtain backscattered SERS signal lights at different wavelengths;
converting the backscattered SERS signal lights at different wavelengths, to obtain time-resolved electrical signal signals, and performing time-domain analysis on the time-resolved electrical signals;
subtracting a Raman signal of a transmission optical fiber itself of an optical fiber SERS probe within the duration of a pulse by adding and averaging a plurality of Raman pulse signals, to obtain a backscattered SERS signal of the object to be measured; and
processing the backscattered SERS signal of the object to be measured, to obtain a SERS spectrum of the object to be measured at a remote detection point.

5. The method for remote detection of SERS spectra according to claim 4 , wherein the splitting the backscattered SERS signal light to obtain backscattered SERS signal light at different wavelengths comprises:
fixing a grating in a monochromator at a determined position, to obtain a backscattered SERS signal light at the current moment, the backscattered SERS signal light including a plurality of pulse signal lights;
performing averaging and background removal processing on the plurality of pulse signal lights, to obtain a backscattered SERS signal light at a wavelength; and
changing the position of the grating, to obtain backscattered SERS signal lights at different wavelengths.

6. A method for remote detection of SERS spectra, the method being applicable to the system for remote detection of SERS spectra according claim 2 , the method comprising:
obtaining pulsed laser light, the pulsed laser light being a Raman excitation light;
detecting an object to be measured by using the Raman excitation light, to obtain a backscattered SERS signal light;
splitting the backscattered SERS signal light, to obtain backscattered SERS signal lights at different wavelengths;
converting the backscattered SERS signal lights at different wavelengths, to obtain time-resolved electrical signal signals, and performing time-domain analysis on the time-resolved electrical signals;
subtracting a Raman signal of a transmission optical fiber itself of an optical fiber SERS probe within the duration of a pulse by adding and averaging a plurality of Raman pulse signals, to obtain a backscattered SERS signal of the object to be measured; and
processing the backscattered SERS signal of the object to be measured, to obtain a SERS spectrum of the object to be measured at a remote detection point.

7. The method for remote detection of SERS spectra according to claim 6 , wherein the splitting the backscattered SERS signal light to obtain backscattered SERS signal light at different wavelengths comprises:
fixing a grating in a monochromator at a determined position, to obtain a backscattered SERS signal light at the current moment, the backscattered SERS signal light including a plurality of pulse signal lights;
performing averaging and background removal processing on the plurality of pulse signal lights, to obtain a backscattered SERS signal light at a wavelength; and
changing the position of the grating, to obtain backscattered SERS signal lights at different wavelengths.

8. The system for remote detection of SERS spectra according to claim 1 , wherein the optical fiber SERS probe comprises a transmission section and a detection section, where the transmission section is configured to transmit the Raman excitation light and the backscattered SERS signal light; and the detection section is configured to generate the SERS signal light.

9. The system for remote detection of SERS spectra according to claim 8 , wherein the transmission section is a quartz fiber; the detection section comprises an optical fiber with precious metal nanoparticles formed on the surface.

10. A method for remote detection of SERS spectra, the method being applicable to the system for remote detection of SERS spectra according claim 9 , the method comprising:
obtaining pulsed laser light, the pulsed laser light being a Raman excitation light;
detecting an object to be measured by using the Raman excitation light, to obtain a backscattered SERS signal light;
splitting the backscattered SERS signal light, to obtain backscattered SERS signal lights at different wavelengths;
converting the backscattered SERS signal lights at different wavelengths, to obtain time-resolved electrical signal signals, and performing time-domain analysis on the time-resolved electrical signals;
subtracting a Raman signal of a transmission optical fiber itself of an optical fiber SERS pro

Assignees

• Univ Dongguan Technology

Inventors

• Liu Ye
• Zhou Fei
• Wang Hongcheng

Classifications

• H01S3/302

  in an optical fibre · CPC title

• G01K11/32

  using changes in transmittance, scattering or luminescence in optical fibres · CPC title

• G01J3/44

  Raman spectrometry; Scattering spectrometry {; Fluorescence spectrometry} · CPC title

• G01J3/0218

  using optical fibers · CPC title

• G01N21/658 Primary

  enhancement Raman, e.g. surface plasmons · CPC title