Fiber optic tweezers CARS microspectroscopy measurement system and method based on composite multi-core optical fiber

Abstract

The present invention discloses a fiber optic tweezers CARS microspectroscopy measurement system and method based on a composite multi-core optical fiber. The system includes a fiber optic tweezers CARS laser source, a light source beam combining unit, a composite multi-core optical fiber coupling unit, a composite multi-core optical fiber, a composite multi-core optical fiber converging unit, and a signal acquisition and processing unit. The pump ultrafast pulse light, Stokes ultrafast pulse light, and capture ultrafast pulse light generated by the fiber optic tweezers CARS laser source are beam combined and coupled into the composite multi-core optical fiber for transmission via the composite multi-core optical fiber coupling unit. The light is then emitted by the composite multi-core optical fiber converging unit and converged on the particle to be measured, thereby simultaneously achieving optical tweezers capture of the particle to be measured and measurement of the CARS signal. The present invention can achieve system miniaturization and integration, realize real-time in-situ CARS signal measurement of a single tiny particle, and has broad application prospects in the fields of materials analysis and biomedicine.

Description

Technical Field

[0001] The present invention relates to the field of optical fiber optics and coherent Raman spectroscopy detection, and in particular to a fiber optic tweezers CARS microspectroscopy measurement system and method. Background Art

[0002] Coherent anti-Stokes Raman scattering (CARS) microspectroscopy has broad applications in the life sciences due to its lack of fluorescent labeling, high sensitivity, and unique chemical selectivity. CARS signal generation requires the simultaneous incidence of two pulsed light beams, each with a frequency difference equal to the molecular vibration frequency of the target particle, at the same location on the target particle, thereby achieving resonant excitation of the CARS signal. Currently, however, bioparticle detection is primarily performed in liquid environments, where Brownian motion causes the particles to continuously shift their positions, making long-term, stable CARS microspectroscopy measurements virtually impossible. The development of optical tweezers technology has made it possible to use lasers to non-contactly immobilize and manipulate particles in three-dimensional space. A laser beam, after being strongly focused, forms a strong gradient force optical trap at the target particle, suppressing its Brownian motion in the liquid environment and thus achieving stable immobilization. Traditional optical tweezers combined with Raman scattering techniques employ spatial optical paths, which are complex and inefficient. Summary of the Invention

[0003] To overcome the shortcomings of the existing technology, the present invention aims to propose a fiber optic tweezers CARS microspectroscopy measurement system and method based on a composite multi-core optical fiber. Combined with the innovative composite multi-core optical fiber structure design, a related system is constructed to achieve real-time in situ capture of tiny particles in the sample to be tested and perform CARS signal measurement.

[0004] In the first aspect, the present invention provides a fiber tweezers CARS micro-spectroscopy measurement system based on a composite multi-core optical fiber, which at least includes a tweezers CARS laser source 1, a light source beam combining unit, a composite multi-core optical fiber coupling unit 6, a composite multi-core optical fiber 7, a composite multi-core optical fiber converging unit 8, a filter 10 and a signal acquisition and processing system 11; wherein: the fiber tweezers CARS laser source 1 outputs a pump ultrafast pulse light 21, a Stokes ultrafast pulse light 22 and a capture ultrafast pulse light 23 with the same polarization state, the same repetition frequency and adjustable pulse delay to the light source beam combining unit; the light beams combined by the light source beam combining unit are coupled into the composite multi-core optical fiber 7 through the composite multi-core optical fiber coupling unit 6, wherein the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 are coupled into the central air core of the composite multi-core optical fiber 7, and the composite multi-core optical fiber 7 adopts a multi-core optical fiber. The composite optical fiber structure comprises a coating layer 31, an outer cladding layer 32, a cladding tube 33, and an air core 34 from the outside to the inside, and four solid cores 35 are distributed in the outer cladding layer 32. The captured ultrafast pulse light 23 is coupled into the solid core 35 of the composite multi-core optical fiber 7; the captured ultrafast pulse light 23 is converged by the composite multi-core optical fiber converging unit 8 to form a gradient force optical trap to capture the particle to be measured 9; the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 are converged to the particle to be measured 9 by the composite multi-core optical fiber converging unit 8, and the optical fiber optical tweezers CARS laser source 1 is adjusted so that the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 overlap in time to excite CARS signal light; the CARS signal light passes through the filter 10 to filter out stray light and is collected and processed by the signal acquisition and processing system 11.

[0005] In some embodiments, the light source beam combining unit further includes a first reflector 2, a first dichroic mirror 3, a second dichroic mirror 4 and a second reflector 5. The pump ultrafast pulse light 21 is reflected by the first reflector 2 and then combined with the Stokes ultrafast pulse light 22 at the first long-pass dichroic mirror 3. The capture ultrafast pulse light 23 is reflected by the second reflector 5 and then combined with the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 at the second long-pass dichroic mirror 4.

[0006] In some embodiments, the pump ultrafast pulse light 21 has the ability to continuously tune the optical wavelength and adjust the pulse delay, with a pulse width of 100 to 10,000 fs, a central wavelength of 800 to 1015 nm, and a repetition frequency of 40 to 80 MHz;

[0007] In some embodiments, the Stokes ultrafast pulse light 22 has the ability to continuously tune the optical wavelength and adjust the pulse delay, with a pulse width of 100 to 10,000 fs, a central wavelength of 1015 to 1070 nm, and a repetition frequency of 40 to 80 MHz;

[0008] In some embodiments, the captured ultrafast pulse light 23 has a fixed wavelength, a pulse width of 100 to 1000 fs, a central wavelength of 780 nm, and a repetition frequency of 40 to 80 MHz;

[0009] In some embodiments, the first long-pass dichroic mirror 3 transmits light with a wavelength greater than its cutoff wavelength and reflects light with a wavelength less than its cutoff wavelength, wherein the cutoff wavelength is greater than or equal to the wavelength tuning lower limit of the Stokes ultrafast pulse light 22, thereby transmitting the Stokes ultrafast pulse light 22 and reflecting the pump ultrafast pulse light 21;

[0010] In some embodiments, the second long-pass dichroic mirror 4 transmits light with a wavelength greater than its cutoff wavelength and reflects light with a wavelength less than its cutoff wavelength, and its cutoff wavelength is greater than or equal to the wavelength tuning lower limit of the pump ultrafast pulse light 21, thereby transmitting the Stokes ultrafast pulse light 22 and the pump ultrafast pulse light 21, and reflecting the captured ultrafast pulse light 23.

[0011] In a second aspect, the present invention provides a method for measuring CARS microscopic spectra using optical fiber tweezers based on a composite multi-core optical fiber, characterized by comprising:

[0012] Step 1: Use the fiber tweezers CARS laser source 1 to output the pump ultrafast pulse light 21, Stokes ultrafast pulse light 22, and trapping ultrafast pulse light 23 with the same polarization state, the same repetition frequency, and adjustable pulse delay. The wavelengths of the Stokes ultrafast pulse light 21 and the pump ultrafast pulse light 22 are continuously tuned, and the wavenumber difference between the two beams of light wavelengths matches the molecular vibration frequency to excite the CARS signal;

[0013] Step 2: The pump ultrafast pulse light 21 is reflected by the first reflector 2 and then combined with the Stokes ultrafast pulse light 22 at the first long-pass dichroic mirror 3. The capture ultrafast pulse light 23 is reflected by the second reflector 5 and then combined with the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 at the second long-pass dichroic mirror 4.

[0014] Step 3: The combined light beams are coupled into the composite multi-core optical fiber 7 through the composite multi-core optical fiber coupling unit 6, wherein the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 are coupled into the central air core 34 of the composite multi-core optical fiber 7, and the capture ultrafast pulse light 23 is coupled into the solid core 35 of the composite multi-core optical fiber;

[0015] Step 4: The captured ultrafast pulse light 23 is converged by the composite multi-core optical fiber converging unit 8 to form a gradient force optical trap to capture the particles to be detected;

[0016] Step 5: The pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 are converged to the particle to be measured 9 via the composite multi-core optical fiber convergence unit 8, and the two pulses are spatially overlapped; the optical tweezers CARS laser source 1 is adjusted to make the pulse times of the output pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 overlap, thereby stimulating CARS signal light;

[0017] Step 6: The CARS signal light passes through the filter 10 to remove stray light, and is collected and processed by the signal collection and processing system 11.

[0018] In the third aspect, the present invention provides a composite multi-core optical fiber structure, wherein the composite multi-core optical fiber 7 adopts a composite optical fiber structure consisting of a multi-core structure and a hollow anti-resonance structure, and its optical fiber structure is, from the outside to the inside, a coating layer 31, an outer cladding 32, a cladding tube 33, and an air core 34, and four solid cores 35 are distributed in the outer cladding 32.

[0019] Compared with the prior art, the present invention innovatively proposes a composite multi-core optical fiber as a transmission device for the two probe beams and the captured pulse light of CARS. The composite multi-core optical fiber 7 adopts a composite optical fiber structure design consisting of a multi-core structure and a hollow anti-resonance structure. The optical fiber structure comprises a coating layer 31, an outer cladding 32, a cladding tube 33, and an air core 34 from the outside to the inside. Four solid cores 35 are distributed in the outer cladding 32 for transmitting the captured ultrafast pulse light 23. The air core 34 in the center is used to transmit the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light. Fast pulse light 22 eliminates the four-wave mixing background noise and pulse walk-off effects brought by solid optical fiber; it simultaneously realizes the optical tweezers capture of the particles to be tested and the CARS signal excitation detection. By combining fiber optic tweezers and fiber nonlinear spectroscopy technology, it greatly simplifies the instrument structure and improves the system integration, reducing the system cost; it significantly enhances the control ability and detection stability of the detection object, and can realize real-time in-situ CARS microscopic spectrum long-term tracking measurement of single tiny particles in three-dimensional space, which will help promote the application of CARS detection systems in biomedicine, life sciences and other fields. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the architecture of a fiber optic tweezers CARS microspectroscopy measurement system based on a composite multi-core optical fiber of the present invention;

[0021] Figure 2 This is the end face structure diagram of the composite multi-core optical fiber;

[0022] Figure 3 This is a structural diagram of a composite multi-core optical fiber convergence unit;

[0023] Figure 4 Schematic diagram of the overall process of the fiber optic tweezers CARS microspectroscopy measurement method based on a composite multi-core optical fiber of the present invention;

[0024] Reference numerals:

[0025] 1. Fiber tweezers CARS laser source, 2. First reflector, 3. First long-pass dichroic mirror, 4. Second long-pass dichroic mirror, 5. Second reflector, 6. Composite multi-core fiber coupling unit, 7. Composite multi-core fiber, 8. Composite multi-core fiber converging unit, 9. Detected particles, 10. Optical filter, 11. Signal acquisition and processing system;

[0026] 21. Pump ultrafast pulse light, 22. Stokes pulse light, 23. Trapping pulse light;

[0027] 31. coating layer, 32. outer cladding layer, 33. cladding tube, 34. air core, 35. solid core;

[0028] 41. Central meta-lens unit, 42. Outer ring meta-lens unit. DETAILED DESCRIPTION

[0029] The technical solution proposed by the present invention is described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] The present invention proposes a fiber optic tweezers CARS microspectroscopy measurement unit and method based on a composite multi-core optical fiber. A specially designed composite multi-core optical fiber is used as a transmission device for CARS detection light and capture pulse light. This unit can simultaneously capture the particles to be measured and measure the CARS signal. This simplifies the system structure, improves system integration, and reduces system cost, enabling real-time, in-situ CARS microspectral measurement of a single tiny particle in three-dimensional space.

[0031] like Figure 1 As shown, in a fiber optic tweezers CARS micro-spectroscopy measurement system based on a composite multi-core optical fiber of the present invention, the system includes a fiber optic tweezers CARS laser source 1, a light source beam combining unit, a composite multi-core optical fiber coupling unit 6, a composite multi-core optical fiber 7, a composite multi-core optical fiber converging unit 8 and a signal acquisition and processing system 11.

[0032] like Figure 2As shown, the composite multi-core optical fiber 7 adopts a composite optical fiber structure design consisting of a multi-core structure and a hollow anti-resonance structure. The optical fiber structure is composed of a coating layer 31, an outer cladding 32, a cladding tube 33, and an air core 34 from the outside to the inside. Four solid cores 35 are distributed in the outer cladding 32 for transmitting the captured ultrafast pulse light 23. The air core 34 located in the center is used to transmit the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22, eliminating the four-wave mixing background noise and pulse walk-off effects brought by the solid optical fiber. The typical length of the composite multi-core optical fiber 7 is in the range of 1 to 10 meters.

[0033] Wherein: the fiber optical tweezers CARS laser source 1 outputs a pump ultrafast pulse light 21, a Stokes ultrafast pulse light 22 and a capture ultrafast pulse light 23 with the same polarization state, the same repetition frequency and adjustable pulse delay; the light source beam combining unit further comprises a first reflector 2, a first dichroic mirror 3, a second dichroic mirror 4 and a second reflector 5; the pump ultrafast pulse light 21 is reflected by the first reflector 2 and then combined with the Stokes ultrafast pulse light 22 at the first long-pass dichroic mirror 3, the capture ultrafast pulse light 23 is reflected by the second reflector 5 and then combined with the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 at the second long-pass dichroic mirror 4; the combined light beam is coupled into the composite multi-core optical fiber 7 through the composite multi-core optical fiber coupling unit 6, wherein the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 are coupled into the composite multi-core optical fiber 7 located at the end face of the composite multi-core optical fiber 7 The air fiber core 34 is located at the center position of the composite multi-core optical fiber 7, and the captured ultrafast pulse light 23 is coupled into the solid fiber core 35 on the outer cladding 32 of the end face of the composite multi-core optical fiber 7; the captured ultrafast pulse light 23 is converged by the composite multi-core optical fiber converging unit 8 to form a gradient force optical trap to capture the particle 9 to be measured; the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 are converged to the particle 9 to be measured by the composite multi-core optical fiber converging unit 8, and the fiber optical tweezers CARS laser source 1 is adjusted so that the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 overlap in time to excite the CARS signal light; the signal acquisition and processing unit collects the CARS signal light through photoelectric conversion, and performs denoising, baseline correction and normalization on the spectral signal; if necessary, the system is further provided with a filter 10, and the CARS signal light is filtered out of stray light after passing through the filter 10, and then collected and processed by the signal acquisition and processing system 11.

[0034] The pump ultrafast pulse light 21 has the ability to continuously tune the optical wavelength and adjust the pulse delay, with a pulse width of 100 to 10,000 fs, a central wavelength of 800 to 1015 nm, and a repetition frequency of 40 to 80 MHz;

[0035] The Stokes ultrafast pulse light 22 has the ability to be continuously tuned and pulse delay adjusted, with a pulse width of 100 to 10,000 fs, a central wavelength of 1015 to 1070 nm, and a repetition frequency of 40 to 80 MHz.

[0036] The captured ultrafast pulse light 23 has a fixed wavelength, a pulse width of 100 to 1000 fs, a central wavelength of 780 nm, and a repetition frequency of 40 to 80 MHz;

[0037] The first reflector 2 is used to reflect the pump ultrafast pulse light 21 .

[0038] The first long-pass dichroic mirror 3 transmits light with a wavelength greater than its cutoff wavelength and reflects light with a wavelength less than its cutoff wavelength. Its cutoff wavelength is greater than or equal to the wavelength tuning lower limit of the Stokes ultrafast pulse light 22, thereby transmitting the Stokes ultrafast pulse light 22 and reflecting the pump ultrafast pulse light 21.

[0039] The second long-pass dichroic mirror 4 transmits light with a wavelength greater than its cutoff wavelength and reflects light with a wavelength less than its cutoff wavelength. Its cutoff wavelength is greater than or equal to the wavelength tuning lower limit of the pump ultrafast pulse light 21, thereby transmitting the Stokes ultrafast pulse light 22 and the pump ultrafast pulse light 21 and reflecting the captured ultrafast pulse light 23.

[0040] The second reflector 5 is used to reflect the captured ultrafast pulse light 23 .

[0041] The composite multi-core fiber coupling unit 6 is composed of a glass lens and a meta-lens. The glass lens is used to couple the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 into the central air core of the composite multi-core fiber 7, and the meta-lens is used to couple the captured ultrafast pulse light 23 into the solid core 35 of the composite multi-core fiber 7. The length of the composite multi-core fiber 7 is typically in the range of 1 to 10 meters.

[0042] The signal acquisition and processing system 11 is composed of a highly sensitive photodetector, a drive circuit, an acquisition circuit, and a computer, and realizes the conversion of photoelectric signals and the acquisition and processing of electrical signals. Types of highly sensitive photodetectors include photomultiplier tubes and single photon detectors.

[0043] like Figure 3 As shown, the composite multi-core fiber converging unit 8 is implemented by a meta-lens structure, which consists of a central meta-lens unit 41 and an outer ring meta-lens unit 42. The central meta-lens unit 41 is used to converge the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22, and the outer ring meta-lens unit 42 is used to converge the capture ultrafast pulse light 23.

[0044] The filter 10 is a bandpass filter that only allows CARS signal light to pass through and is used to filter out stray light;

[0045] The signal acquisition and processing system 11 is composed of a highly sensitive photodetector, a drive circuit, an acquisition circuit, and a computer, and realizes the conversion of photoelectric signals and the acquisition and processing of electrical signals. Types of highly sensitive photodetectors include photomultiplier tubes and single photon detectors.

[0046] like Figure 4 As shown, the present invention provides a fiber optic tweezers CARS microspectroscopy measurement method based on a composite multi-core optical fiber, the method comprising the following steps:

[0047] Step 1: Use the fiber tweezers CARS laser source 1 to output the pump ultrafast pulse light 21, Stokes ultrafast pulse light 22, and trapping ultrafast pulse light 23 with the same polarization state, the same repetition frequency, and adjustable pulse delay. The wavelengths of the Stokes ultrafast pulse light 21 and the pump ultrafast pulse light 22 are continuously tuned, and the wavenumber difference between the two beams of light wavelengths matches the molecular vibration frequency to excite the CARS signal;

[0048] Step 2: The pump ultrafast pulse light 21 is reflected by the first reflector 2 and then combined with the Stokes ultrafast pulse light 22 at the first long-pass dichroic mirror 3. The capture ultrafast pulse light 23 is reflected by the second reflector 5 and then combined with the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 at the second long-pass dichroic mirror 4.

[0049] Step 3: The combined light beams are coupled into the composite multi-core optical fiber 7 through the composite multi-core optical fiber coupling unit 6, wherein the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 are coupled into the central air core 34 of the composite multi-core optical fiber 7, and the capture ultrafast pulse light 23 is coupled into the outer ring core 35 of the composite multi-core optical fiber;

[0050] Step 4: The captured ultrafast pulse light 23 is converged by the composite multi-core optical fiber converging unit 8 to form a gradient force optical trap to achieve the capture of the particles to be detected;

[0051] Step 5: The pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 are converged to the particle to be measured 9 via the composite multi-core optical fiber converging unit 8. The two pulses overlap spatially and the convergence spot is less than 1 μm. The optical tweezers CARS laser source 1 is adjusted to make the pulse time of the output pump ultrafast pulse light 21 and the Stokes ultrafast pulse light 22 overlap, thereby stimulating CARS signal light.

[0052] Step 6: The CARS signal light passes through the filter 10 to remove stray light, and is collected and processed by the signal collection and processing system 11.

[0053] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included in the scope of protection of the present invention. The above description is only a preferred embodiment of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications made without departing from the principles of the present invention should also be considered to fall within the scope of protection of the present invention.

Claims

1. A fiber optic tweezers CARS microspectroscopy measurement system based on a composite multi-core optical fiber, characterized in that: The invention comprises at least an optical tweezers CARS laser source (1), a light source beam combining unit, a composite multi-core fiber coupling unit (6), a composite multi-core fiber (7), a composite multi-core fiber converging unit (8) and a signal acquisition and processing unit (11); wherein: the optical fiber optical tweezers CARS laser source (1) outputs a pump ultrafast pulse light (21), a Stokes ultrafast pulse light (22) and a capture ultrafast pulse light (23) with the same polarization state, the same repetition frequency and adjustable pulse delay to the light source beam combining unit; the light beams combined by the light source beam combining unit are coupled into the composite multi-core fiber (7) through the composite multi-core fiber coupling unit (6), wherein the pump ultrafast pulse light (21) and the Stokes ultrafast pulse light (22) are coupled into the central air core of the composite multi-core fiber (7), and the composite multi-core fiber (7) adopts a composite fiber structure composed of a multi-core structure and a hollow anti-resonance structure, wherein The optical fiber structure comprises, from outside to inside, a coating layer (31), an outer cladding layer (32), a cladding tube (33), and an air core (34), and four solid cores (35) are distributed in the outer cladding layer (32). The captured ultrafast pulse light (23) is coupled into the solid core (35) of the composite multi-core optical fiber (7); the captured ultrafast pulse light (23) is converged by the composite multi-core optical fiber convergence unit (8) to form a gradient force light trap to capture the particle to be measured (9); the pump ultrafast pulse light (21) and the Stokes ultrafast pulse light (22) are converged to the particle to be measured (9) by the composite multi-core optical fiber convergence unit (8), and the optical fiber optical tweezers CARS laser source (1) is adjusted so that the pump ultrafast pulse light (21) and the Stokes ultrafast pulse light (22) overlap in time to excite CARS signal light; and the signal acquisition and processing unit (11) acquires and processes the CARS signal light.

2. The fiber optic tweezers CARS microspectroscopy measurement system based on a composite multi-core optical fiber according to claim 1, characterized in that: The light source beam combining unit further comprises a first reflector (2), a first long-pass dichroic mirror (3), a second long-pass dichroic mirror (4) and a second reflector (5); the pump ultrafast pulse light (21) is reflected by the first reflector (2) and then combined with the Stokes ultrafast pulse light (22) at the first long-pass dichroic mirror (3); the capture ultrafast pulse light (23) is reflected by the second reflector (5) and then combined with the pump ultrafast pulse light (21) and the Stokes ultrafast pulse light (22) at the second long-pass dichroic mirror (4).

3. The fiber optic tweezers CARS microspectroscopy measurement system based on a composite multi-core optical fiber according to claim 1, characterized in that: The pump ultrafast pulse light (21) has the ability to continuously tune the optical wavelength and adjust the pulse delay, with a pulse width of 100 to 10,000 fs, a central wavelength of 800 to 1015 nm, and a repetition frequency of 40 to 80 MHz.

4. The fiber optic tweezers CARS microspectroscopy measurement system based on a composite multi-core optical fiber according to claim 1, characterized in that: The Stokes ultrafast pulse light (22) has the ability to continuously tune the optical wavelength and adjust the pulse delay, with a pulse width of 100 to 10,000 fs, a central wavelength of 1015 to 1070 nm, and a repetition frequency of 40 to 80 MHz.

5. The fiber optic tweezers CARS microspectroscopy measurement system based on a composite multi-core optical fiber according to claim 1, characterized in that: The captured ultrafast pulse light (23) has a fixed wavelength, a pulse width of 100 to 1000 fs, a central wavelength of 780 nm, and a repetition frequency of 40 to 80 MHz.

6. The fiber optic tweezers CARS microspectroscopy measurement system based on a composite multi-core optical fiber according to claim 2, characterized in that: The first long-pass dichroic mirror (3) transmits light having a wavelength greater than its cut-off wavelength and reflects light having a wavelength less than its cut-off wavelength, wherein the cut-off wavelength is greater than or equal to the wavelength tuning lower limit of the Stokes ultrafast pulse light (22), thereby transmitting the Stokes ultrafast pulse light (22) and reflecting the pump ultrafast pulse light (21).

7. The fiber optic tweezers CARS microspectroscopy measurement system based on a composite multi-core optical fiber according to claim 2, characterized in that: The second long-pass dichroic mirror (4) transmits light with a wavelength greater than its cut-off wavelength and reflects light with a wavelength less than its cut-off wavelength, wherein the cut-off wavelength is greater than or equal to the wavelength tuning lower limit of the pump ultrafast pulse light (21), thereby transmitting the Stokes ultrafast pulse light (22) and the pump ultrafast pulse light (21) and reflecting the captured ultrafast pulse light (23).

8. A fiber optic tweezers CARS microspectroscopy measurement method based on a composite multi-core fiber implemented by a fiber optic tweezers CARS microspectroscopy measurement system based on a composite multi-core fiber according to any one of claims 1 to 7, characterized in that: include: Step 1: Use a fiber tweezers CARS laser source (1) to output a pump ultrafast pulse light (21), a Stokes ultrafast pulse light (22), and a capture ultrafast pulse light (23) with the same polarization state, the same repetition frequency, and adjustable pulse delay. The wavelengths of the Stokes ultrafast pulse light (22) and the pump ultrafast pulse light (21) are continuously tuned, and the wavenumber difference between the wavelengths of the two beams matches the molecular vibration frequency to excite the CARS signal. Step 2: The pump ultrafast pulse light (21) is reflected by the first reflector (2) and then combined with the Stokes ultrafast pulse light (22) at the first long-pass dichroic mirror (3); the capture ultrafast pulse light (23) is reflected by the second reflector (5) and then combined with the pump ultrafast pulse light 21 and the Stokes ultrafast pulse light (22) at the second long-pass dichroic mirror (4); Step 3: The light beams after light source combination are coupled into the composite multi-core optical fiber (7) through the composite multi-core optical fiber coupling unit (6), wherein the pump ultrafast pulse light (21) and the Stokes ultrafast pulse light (22) are coupled into the central air core (34) of the composite multi-core optical fiber (7), and the capture ultrafast pulse light (23) is coupled into the solid core (35) of the composite multi-core optical fiber; Step 4: The captured ultrafast pulse light (23) is converged through the composite multi-core optical fiber convergence unit (8) to form a gradient force optical trap to capture the particles to be measured; Step 5: The pump ultrafast pulse light (21) and the Stokes ultrafast pulse light (22) are converged to the particle to be measured (9) via the composite multi-core optical fiber convergence unit (8), and the two pulses overlap in space; The optical tweezers CARS laser source (1) is adjusted so that the pulse times of the output pump ultrafast pulse light (21) and the Stokes ultrafast pulse light (22) overlap, thereby stimulating CARS signal light; Step 6: Use the acquisition and processing unit (11) to acquire and process the CARS signal light signal.

Images