CN118817660A - Detection system and method based on tunable laser - Google Patents

Abstract

The present invention relates to the technical field of spectrum analysis instruments, and in particular to a detection system and method based on tunable lasers. The system comprises a tunable laser module and a Raman spectrometer. The tunable laser module emits lasers of different wavelengths to a sample to be tested. The sample to be tested generates corresponding Raman light after being excited by the lasers of different wavelengths. The Raman light forms a corresponding Raman spectrum in the Raman spectrometer. In the method, all Raman spectra are grouped, and the difference between two Raman spectra in each group of Raman spectra is calculated to obtain a differential Raman spectrum, and then the average value of all the differential Raman spectra is taken, so as to achieve the purpose of improving the signal-to-noise ratio and eliminating fluorescence interference.

Description

Detection system and method based on tunable laser

Technical Field

The invention belongs to the technical field of spectrum analysis instruments, and in particular relates to a detection system and method based on tunable laser.

Background Art

Breast cancer is a common malignant tumor in women, and ranks first in the incidence of cancer in women. The incidence of breast cancer is still increasing year by year. Breast cancer screening usually adopts the method of pathological examination. Patients with breast cancer need to undergo puncture or excisional biopsy, which causes trauma, great mental stress and high medical expenses.

Raman spectroscopy has the characteristics of no sample preparation, no contact with samples, no destruction of sample structure, simple and fast analysis and high resolution, so it can be used for disease prediction, diagnosis and efficacy judgment. However, the background fluorescence of biological molecules is strong, which can easily interfere with the test results, resulting in low measurement accuracy and even misjudgment in severe cases. Most of the spectrometers currently on the market for detecting tumors (including breast cancer) use plane gratings, which makes the current spectrometers have low resolution and cannot detect the details of the sample in place.

Summary of the invention

In view of this, the present invention aims to provide a detection system and method based on tunable laser, in which a tunable laser module emits lasers of different wavelengths to excite the sample to be tested to emit corresponding Raman light and obtain a Raman spectrum. In the method, different Raman spectra are differentiated and then averaged, thereby improving the signal-to-noise ratio and eliminating fluorescence interference.

To achieve the above object, the technical solution created by the present invention is implemented as follows:

A detection system based on tunable laser includes a tunable laser module and a Raman spectrometer; wherein the tunable laser module emits lasers of different wavelengths to a sample to be tested; the sample to be tested generates corresponding Raman light after being excited by the lasers of different wavelengths; and the Raman light forms a corresponding Raman spectrum in the Raman spectrometer;

The Raman spectrometer includes a dichroic mirror, a Raman filter group, an AOTF, an echelle grating and a detector; wherein lasers of different wavelengths are reflected by the dichroic mirror onto the sample to be tested; the Raman light generated by the sample to be tested enters the Raman filter group through the dichroic mirror, and the Raman filter group filters the input Raman light; the filtered Raman light enters the AOTF; the AOTF selects Raman light of a specific wavelength from the input Raman light, and transmits the Raman light of the specific wavelength to the echelle grating; the Raman light of the specific wavelength is diffracted on the echelle grating, and the diffracted Raman light enters the detector to obtain a Raman spectrum;

The tunable laser module includes a tunable laser, a beam expander lens, a collimator lens and a cylindrical mirror; wherein the tunable laser emits point lasers of different wavelengths, and the point lasers pass through the beam expander lens, the collimator lens and the cylindrical mirror in sequence, and the formed linear lasers are irradiated onto the sample to be tested to form corresponding Raman light.

Furthermore, the Raman filter group includes at least two Raman filters, and the Raman light passing through the dichroic mirror passes through each Raman filter in sequence.

Furthermore, a focusing lens is arranged between the sample to be tested and the dichroic mirror, and the sample to be tested is located at the focal plane of the focusing lens.

Furthermore, a prism is arranged between the AOTF and the echelle grating, so that the propagation direction of the Raman light of a specific wavelength selected by the AOTF changes after passing through the prism.

Furthermore, a first free-form surface reflector is arranged between the prism and the echelle grating, and a second free-form surface reflector is arranged between the echelle grating and the detector. The Raman light passing through the prism is reflected onto the echelle grating by the first free-form surface reflector; the Raman light diffracted by the echelle grating is reflected by the second free-form surface reflector and focused into the detector.

Furthermore, it also includes a loading platform; wherein the loading platform includes an electric displacement platform, and the sample to be tested is set on the electric displacement platform.

Furthermore, the tunable laser module includes a tunable laser; wherein the tunable laser emits point-shaped lasers of different wavelengths to the sample to be tested, and the sample to be tested generates corresponding Raman light after being excited by the point-shaped laser.

A detection method based on tunable laser, applicable to the detection system based on tunable laser provided by the present invention, comprises the following steps:

S1: Control the tunable laser module to emit point lasers of different wavelengths to the sample to be tested, and obtain the Raman spectrum corresponding to the Raman light generated by the sample to be tested;

S2: group all Raman spectra, each group of Raman spectra includes two different Raman spectra;

S3: Calculate the difference of each group of Raman spectra to obtain the differential Raman spectrum of each group of Raman spectra, and then calculate the average value of all the differential Raman spectra to obtain the final differential Raman spectrum.

Compared with the prior art, the invention can achieve the following beneficial effects:

(1) In the tunable laser detection system described in the present invention, a tunable laser is used to emit lasers of different wavelengths, thereby exciting corresponding Raman light; in the tunable laser detection method, all Raman spectra are grouped in pairs to obtain differential Raman spectra, and then the average value of the differential Raman spectra is taken, thereby achieving the purpose of improving the signal-to-noise ratio and eliminating fluorescence interference;

(2) In the tunable laser-based detection system created by the present invention, a mid-step grating is used to achieve high diffraction efficiency of multiple orders at the same time, thereby improving the spectral resolution of the system; the free-form surface reflector has a high degree of freedom and can better reflect light into the detector compared with ordinary reflectors, thereby further improving the resolution of the Raman spectrum.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawings constituting part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments and descriptions of the present invention are used to explain the present invention and do not constitute an improper limitation on the present invention. In the drawings:

FIG1 is a schematic diagram of the optical path structure of a detection system based on tunable laser according to an embodiment of the present invention;

FIG2 is a schematic diagram of the optical path structure of a tunable laser module according to an embodiment of the present invention;

FIG3 is a flow chart of a detection method based on tunable laser according to an embodiment of the present invention.

Description of reference numerals:

1. Sample to be tested; 2. Electric translation stage; 3. Glass slide; 4. Tunable laser; 5. Dichroic mirror; 6. Raman filter group; 7. AOTF; 8. Medium-step grating; 9. Detector; 10. Focusing lens; 11. Raman filter; 12. Prism; 13. First collimating lens; 14. Slit; 15. First free-form surface reflector; 16. Second free-form surface reflector; 17. Beam expander lens; 18. Second collimating lens; 19. Cylindrical mirror.

DETAILED DESCRIPTION

In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and do not constitute a limitation of the invention.

It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, the terms "first", "second", etc. are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", etc. may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

In the description of the invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the invention can be understood according to specific circumstances.

The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments.

As shown in FIG1 , the detection system based on tunable laser described in the embodiment of the invention includes a tunable laser module, a Raman spectrometer and a loading platform. The sample 1 to be tested is placed on the loading platform. The tunable laser module emits lasers of different wavelengths to the sample 1 to be tested. The sample 1 to be tested generates corresponding Raman light after being excited by lasers of different wavelengths. The Raman light obtains the corresponding Raman spectrum in the Raman spectrometer. The loading platform includes an electric translation stage 2. The sample 1 to be tested is fixed on the electric translation stage 2 by a glass slide 3. The electric translation stage 2 drives the sample 1 to be tested to move step by step.

Specific embodiment 1:

The tunable laser module includes a tunable laser 4. The tunable laser 4 emits point-shaped lasers of different wavelengths to the sample 1 to be tested, and the sample to be tested generates corresponding Raman light after being excited by the point-shaped laser.

The Raman spectrometer includes a dichroic mirror 5, a Raman filter group 6, an AOTF (Acousto-optic Tunable Filter) 7, an echelle grating 8 and a detector 9. Lasers of different wavelengths are reflected by the dichroic mirror 5 onto the sample to be tested 1, and the Raman light generated by the sample to be tested 1 enters the Raman filter group 6 through the dichroic mirror 5. In a specific embodiment, a focusing lens 10 is preferably provided between the sample to be tested 1 and the dichroic mirror 5, and the sample to be tested 1 is located at the focal plane of the focusing lens 10, so that lasers of different wavelengths can be reflected by the dichroic mirror 5 and converged onto the sample to be tested 1 through the focusing lens 10, and the Raman light generated by the sample to be tested 1 can also be irradiated onto the dichroic mirror 5 through the focusing lens 10.

The Raman filter group 6 filters the Raman light passing through the dichroic mirror 5. The Raman filter group 6 includes at least two Raman filters 11, and the Raman light passing through the dichroic mirror 5 passes through each Raman filter 11 in sequence. In this specific embodiment, two Raman filters 11 are preferably provided.

The Raman light filtered by the Raman filter group 6 enters the AOTF7. After the AOTF7 quickly and dynamically selects the Raman light of a specific wavelength, it transmits the Raman light of the specific wavelength to the echelle grating 8. In this specific embodiment, a prism 12, a first collimating lens 13, a slit 14 and a first free-form surface reflector 15 are sequentially arranged along the optical path direction between the AOTF7 and the echelle grating 8. Among them, the propagation direction of the Raman light of a specific wavelength quickly selected by the AOTF7 changes after passing through the prism 12, and the propagation direction of the Raman light output by the AOTF7 is corrected. The Raman light emitted from the prism 12 passes through the first collimating lens 13 and enters the slit 14. The slit 14 is placed at the focal plane of the first collimating lens 13 to filter out the stray light in the Raman light to improve the overall resolution of the system. The Raman light emitted from the slit 14 is reflected by the first free-form surface reflector 15 onto the echelle grating 8.

The echelle grating 8 diffracts the irradiated Raman light, and the diffracted Raman light enters the detector 9 to obtain a Raman spectrum. Among them, the Raman light is irradiated on the echelle grating 8, and the echelle grating 8 is used under the Litlow condition (the incident angle i is equal to the diffraction angle φ is equal to the blaze angle θ), thereby obtaining a higher diffraction efficiency. In this specific embodiment, a second free-form surface reflector 16 is provided between the echelle grating 8 and the detector, and the Raman light diffracted by the echelle grating 8 is reflected by the second free-form surface reflector 16 and focused into the detector 9.

In this specific embodiment, the tunable laser 4 emits point-shaped lasers of different wavelengths, and can perform spectrum measurement of Raman light in cooperation with a Raman spectrometer.

Specific embodiment 2:

As shown in FIG2 , the tunable laser module includes a tunable laser 4, a beam expander lens 17, a second collimator lens 18 and a cylindrical mirror 19. The tunable laser 4 emits point lasers of different wavelengths, and the point lasers sequentially pass through the beam expander lens 17, the second collimator lens 18 and the cylindrical mirror 19 to form a linear laser that irradiates the sample 1 to be tested to form corresponding Raman light. The Raman spectrometer in this specific embodiment has the same structure as the Raman spectrometer in specific embodiment 1, and will not be described in detail here.

In this specific embodiment, the tunable laser module emits a linear laser to irradiate the sample 1 to be tested to generate Raman light, and the electric translation stage 2 drives the sample 1 to be tested to move in steps. After each step, the Raman spectrum is measured once using a Raman spectrometer, and the Raman spectra measured after multiple steps are integrated to complete the Raman imaging of the sample 1 to be tested.

A detection method based on tunable laser, applicable to the detection system based on tunable laser provided by the present invention, as shown in FIG3 , comprises the following steps:

S1: Control the tunable laser module to emit point lasers of different wavelengths to the sample to be tested, and obtain the Raman spectrum corresponding to the Raman light generated by the sample to be tested 1. The tunable laser module includes a tunable laser 4 that can emit point lasers of different wavelengths.

S2: grouping all Raman spectra, each group of Raman spectra includes two different Raman spectra.

S3: Calculate the difference of each group of Raman spectra to obtain the differential Raman spectrum of each group of Raman spectra, and then calculate the average value of the spectral lines of all the differential Raman spectra to obtain the final differential Raman spectrum.

It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the disclosure of the present invention can be performed in parallel, sequentially or in different orders, as long as the desired results of the technical solution disclosed in the present invention can be achieved, and this document does not limit this.

The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (8)

1. A tunable laser-based detection system, characterized by: comprises a tunable laser module and a Raman spectrometer; the tunable laser module emits laser with different wavelengths to a sample to be tested; the sample to be tested is excited by lasers with different wavelengths to generate corresponding Raman light; the raman light forms a corresponding raman spectrum in the raman spectrometer;

The Raman spectrometer comprises a dichroic mirror, a Raman filter group, an AOTF, an echelle grating and a detector; the laser light with different wavelengths emitted by the tunable laser module is reflected to the sample to be detected by the dichroic mirror; the Raman light generated by the sample to be detected enters the Raman filter group through the dichroic mirror, and the Raman filter group filters the input Raman light; the filtered Raman light enters the AOTF; the AOTF transmits the Raman light with the specific wavelength to the echelle grating after selecting the Raman light with the specific wavelength from the input Raman light; the Raman light with specific wavelength is diffracted on the echelle grating, and the diffracted Raman light enters the detector to obtain the Raman spectrum;

the tunable laser module comprises a tunable laser, a beam expanding lens, a collimating lens and a cylindrical mirror; the tunable laser emits point-shaped lasers with different wavelengths, and the point-shaped lasers sequentially pass through the beam expanding lens, the collimating lens and the cylindrical mirror to form linear lasers which irradiate the sample to be detected to form corresponding Raman light.

2. The tunable laser-based detection system of claim 1, wherein: the Raman filter group comprises at least 2 Raman filters, and the Raman light transmitted through the dichroic mirror sequentially passes through each Raman filter.

3. The tunable laser-based detection system of claim 1, wherein: a focusing lens is disposed between the sample to be measured and the dichroic mirror, and the sample to be measured is located at a focal plane of the focusing lens.

4. The tunable laser-based detection system of claim 1, wherein: and a prism is arranged between the AOTF and the echelle grating, so that the propagation direction of the Raman light with the specific wavelength selected by the AOTF is changed after passing through the prism.

5. The tunable laser based detection system of claim 4, wherein: a first free-form surface reflecting mirror is arranged between the prism and the echelle grating, a second free-form surface reflecting mirror is arranged between the echelle grating and the detector, and Raman light passing through the prism is reflected to the echelle grating by the first free-form surface reflecting mirror; the raman light diffracted by the echelle grating is reflected by the second freeform mirror and focused into the detector.

6. The tunable laser-based detection system of claim 1, wherein: the device also comprises an object carrying platform; the object carrying platform comprises an electric displacement platform, and the sample to be detected is arranged on the electric displacement platform.

7. The tunable laser based detection system of claim 6, wherein: the tunable laser module comprises a tunable laser; the tunable laser emits point-shaped lasers with different wavelengths to the sample to be detected, and the sample to be detected generates corresponding Raman light after being excited by the point-shaped lasers.

8. A tunable laser-based detection method, which is applicable to the tunable laser-based detection system as defined in claim 7, and is characterized in that: the method comprises the following steps:

S1: controlling the tunable laser module to emit point-shaped lasers with different wavelengths to the sample to be detected, so as to obtain a Raman spectrum corresponding to Raman light generated by the sample to be detected;

S2: grouping all raman spectra, each group comprising two different raman spectra;

S3: and calculating the difference value of each group of Raman spectrum to obtain a differential Raman spectrum of each group of Raman spectrum, and calculating the average value of all the differential Raman spectrums to obtain a final differential Raman spectrum.