A raman spectroscopy system based on a cassegrain structure and a dual optical probe

Abstract

The application discloses a Raman spectrum system based on a Cassegrain structure and double optical probes, which comprises a laser, optical probes one and two, a dichroic mirror, auxiliary mirrors one and two, a main mirror, a sample chamber, a spectrometer host and a computer; the light emitted by the laser is split into two beams of light, which respectively enter the optical probe one and the optical probe two; the emergent light is transmitted by the dichroic mirror and respectively incident to the auxiliary mirror one and the auxiliary mirror two for reflection, and then focused on a sample to be measured in the sample chamber after being reflected by the main mirror; the sample to be measured is excited to generate Raman scattered light; the Raman scattered light returns to the optical probe one and the optical probe two along the original light path, the optical probe one and the optical probe two collect the Raman scattered light and transmit the Raman scattered light to the spectrometer host; the spectrometer host transmits spectral data to the computer, and the computer analyzes the data to obtain concentration information of the sample to be measured. The application can detect the spectrum with high sensitivity, improve technical indexes such as detection limit and improve detection efficiency.

Description

Technical Field

[0001] This invention belongs to the field of laser spectroscopy measurement technology, specifically relating to a Raman spectroscopy system based on a Cassegrain structure and dual optical probes. Background Technology

[0002] Raman spectroscopy is a non-invasive optical analysis method that obtains information about molecular vibrations and rotations by measuring changes in the frequency of scattered light, thereby enabling the analysis of the composition and structure of substances. With the development of science and technology, Raman spectroscopy systems have been widely used in various fields, especially in chemistry, materials science, and biomedicine.

[0003] Currently, Raman spectroscopy faces several unresolved issues. First, the signal intensity of Raman spectra is typically weak, requiring lengthy integration measurements and resulting in low sensitivity. Due to the weak Raman scattering signal, high-power lasers are needed to improve the signal-to-noise ratio, but these can damage the sample. Second, Raman spectra are susceptible to environmental interference. Since the components of the surrounding environment also contribute to Raman scattering, measures are needed to eliminate this interference. This interference can affect the accuracy and reliability of the spectra. Finally, existing Raman spectroscopy instruments are generally complex and cannot meet the requirements for measuring different types of samples. Sample placement and detection operations are complex, resulting in low detection efficiency and limiting the application range of Raman spectroscopy. Summary of the Invention

[0004] In view of this, the present invention provides a Raman spectroscopy system based on a Cassegrain structure and dual optical probes, which can solve the problem of high-sensitivity detection of spectra, improve technical indicators such as detection limit, and increase detection efficiency.

[0005] This invention is achieved through the following technical solution:

[0006] A Raman spectroscopy system based on a Cassegrain structure and dual optical probes includes: a laser, optical probe one, optical probe two, a dichroic mirror, secondary mirror one, secondary mirror two, a primary mirror, a sample chamber, a spectrometer host, and a computer;

[0007] The excitation light emitted by the laser is split into two beams, which enter optical probe one and optical probe two, respectively. The light emitted from optical probe one and optical probe two is transmitted through a dichroic mirror and then reflected by secondary mirror one and secondary mirror two, respectively. The light reflected by secondary mirror one and secondary mirror two is then reflected by the primary mirror and focused onto the sample to be tested in the sample chamber. The sample to be tested is excited to produce Raman scattered light. The Raman scattered light returns along the original optical path to optical probe one and optical probe two, which collect the Raman scattered light and transmit it to the spectrometer host. The spectrometer host transmits the raw spectral information of the Raman scattered light to the computer. The computer analyzes the sample to obtain the concentration information of the sample, thus completing the detection of the sample.

[0008] The dual optical probes, consisting of optical probe one and optical probe two, can realize the emission of excitation light and the collection of Raman scattered light; the Cassegrain optical structure, consisting of secondary mirror one, secondary mirror two, and primary mirror, can simultaneously realize focusing and imaging functions.

[0009] Furthermore, the Raman spectroscopy system also includes: a focusing objective lens, a CCD, a shift stage, and a shift stage controller;

[0010] The displacement stage is installed at the bottom of the sample chamber and can drive the sample chamber to rotate and move up and down along the optical axis perpendicular to the main mirror.

[0011] The displacement stage controller is used to control the movement of the displacement stage, secondary mirror one, and secondary mirror two;

[0012] When using the imaging function of the Cassegrain optical structure, the Raman scattered light generated by the sample being excited returns along the original optical path to optical probe one and optical probe two. After passing through the dichroic mirror, it is reflected by the dichroic mirror into the focusing objective. The focusing objective focuses the Raman scattered light and then it is incident on the CCD. The CCD realizes the position of the sample and generates image information of the sample. The CCD feeds the image information back to the computer. The computer recognizes the image information to realize the position of the sample and feeds the determined information back to the displacement stage controller, which then controls the displacement stage to realize the rotation of the sample chamber and the up and down movement along the optical axis perpendicular to the main mirror.

[0013] When using the focusing function of the Cassegrain optical structure, the position of the focal point on the sample to be tested in the sample chamber can be changed by adjusting the secondary mirror one and secondary mirror two through the displacement stage controller, so as to accurately focus the sample to be tested. At the same time, in conjunction with the position adjustment function of the displacement stage, the multi-point position detection of the sample to be tested can be realized.

[0014] Furthermore, the sample chamber is a polygonal cylindrical structure, with multiple sample storage cavities corresponding to each side of the polygon. The top of each sample storage cavity is open, and the sample to be tested is stored inside. The sample to be tested can be solid, liquid, or gas. Multiple detection windows are provided on the side of the sample chamber, and each detection window is connected to a corresponding sample storage cavity. The laser reflected by the primary mirror enters through the detection window and is focused on the sample to be tested.

[0015] Each sample receiving cavity includes a cylindrical cavity and a rectangular plate cavity. The length directions of the cylindrical cavity and the rectangular plate cavity are both aligned with the length direction of the sample chamber. The plate surface of the rectangular plate cavity is located on the side of the cylindrical cavity, and the rectangular plate cavity is connected to the cylindrical cavity. The cylindrical cavity is closer to the axis of the sample chamber than the rectangular plate cavity, and the rectangular plate cavity is closer to the detection window than the cylindrical cavity.

[0016] When the sample to be tested is solid, the solid sample is placed inside the microfluidic chip, and the microfluidic chip is installed in a rectangular plate cavity;

[0017] When the sample to be tested is a liquid or a gas, the liquid / gas sample is placed in a round glass bottle, which is installed in a cylindrical cavity.

[0018] Furthermore, a focusing mirror is glued to the inner wall surface of the cylindrical cavity near the axis of the sample chamber. The focusing mirror is used to achieve focused reflection of Raman scattered light.

[0019] Furthermore, a microfluidic chip and a circular glass bottle cannot coexist in the same sample storage chamber; different sample storage chambers can store different test samples; when the detection of a test sample is completed, the sample chamber is automatically rotated by the displacement stage to move to the next test sample, realizing continuous automatic measurement of the test sample in the sample chamber.

[0020] Furthermore, the laser is a laser whose power and wavelength can be adjusted simultaneously.

[0021] Beneficial effects:

[0022] (1) This invention provides a Raman spectroscopy system based on a Cassegrain structure and dual optical probes, which can effectively improve the collection efficiency and intensity of spectral signals. The Cassegrain structure is a classic optical system structure with features such as a large field of view, high light collection capability, and excellent imaging quality. In Raman spectroscopy systems, the introduction of the Cassegrain structure can effectively collect scattered light, improve the intensity, signal-to-noise ratio, and collection efficiency of spectral signals, and make Raman spectroscopy measurements more accurate and reliable, especially suitable for the analysis of weak signals, further expanding the measurement range and flexibility. The design of dual optical probes enables the system to collect Raman scattered light from different regions or different angles at the same time, which not only expands the measurement range but also makes it possible to analyze complex samples or different parts, improving measurement accuracy and reliability. Since dual optical probes can collect spectral data from multiple locations at the same time, this method can significantly reduce the measurement time required, thereby shortening the experimental cycle. Ultimately, this invention, based on a Cassegrain structure and a dual-optical-probe Raman spectroscopy system, combines the advantages of both technologies. By optimizing the optical system design and signal processing algorithms, it achieves high-precision and high-sensitivity Raman spectroscopy measurements of the samples under test, making this invention promising for broad applications in material composition analysis, structural characterization, and chemical reaction monitoring. Simultaneously, efficient spectral collection and processing improve overall measurement efficiency, giving this invention greater practical value in scientific research and industrial production.

[0023] (2) The solid sample of the present invention is placed in the microfluidic chip. The microfluidic chip has a dynamic sample loading function, which can prevent the solid sample from floating in the air under microgravity.

[0024] (3) When the Raman spectroscopy system of the present invention completes the detection of a sample, the sample chamber is rotated automatically by the displacement stage to move to the next sample, so as to realize the continuous automatic measurement of the sample in the sample chamber and avoid repeated installation of the sample. At the same time, the position of the sample chamber can be automatically adjusted (i.e., the rotation of the sample chamber and the up and down movement along the optical axis perpendicular to the main mirror), which avoids the problem of inaccurate test caused by uneven sample distribution under microgravity environment, and can realize detection under on-orbit conditions. Attached Figure Description

[0025] Figure 1 This is a structural composition diagram of the present invention;

[0026] Figure 2 This is a structural diagram of the sample chamber of the present invention;

[0027] Figure 3 for Figure 2 Top view;

[0028] Among them, 01-Laser; 02-Optical Probe 1; 03-Optical Probe 2; 04-Dichroic Mirror; 05-Secondary Mirror 1; 06-Secondary Mirror 2; 07-Primary Mirror; 08-Sample Chamber; 09-Displacement Stage; 010-Spectrometer Main Unit; 011-Focusing Objective; 012-CCD; 013-Displacement Stage Controller; 014-Computer; 081-Detection Window; 082-Rectangular Plate Cavity; 083-Cylindrical Cavity; 084-Focusing Mirror. Detailed Implementation

[0029] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0030] This embodiment provides a Raman spectroscopy system based on a Cassegrain structure and dual optical probes. See Appendix. Figure 1 It includes: laser 01, optical probe one 02, optical probe two 03, dichroic mirror 04, secondary mirror one 05, secondary mirror two 06, primary mirror 07, sample chamber 08, spectrometer main unit 010 and computer 014.

[0031] Laser 01 is used to emit excitation light; optical probe 1 02 and optical probe 2 03 are located at the emitting end of laser 01, and optical probe 1 02 and optical probe 2 03 are arranged side by side with parallel output light directions.

[0032] Secondary mirror 1 05 and secondary mirror 2 06 are arranged side by side with their optical axes parallel to each other; among them, secondary mirror 1 05 is opposite to optical probe 1 02, and the direction of the emitted light from optical probe 1 02 is consistent with the optical axis of secondary mirror 1 05; secondary mirror 2 06 is opposite to optical probe 2 03, and the direction of the emitted light from optical probe 2 03 is consistent with the optical axis of secondary mirror 2 06.

[0033] Dichroic mirror 04 is located between the whole consisting of optical probe 1 02 and optical probe 2 03 and the whole consisting of secondary mirror 1 05 and secondary mirror 2 06. The optical axis of dichroic mirror 04 is parallel to the optical axis of secondary mirror 1 05, and dichroic mirror 04 is tilted at 45° relative to the optical axis.

[0034] The primary mirror 07 is an arc-shaped mirror, located between the dichroic mirror 04 and the secondary mirror 05 and the secondary mirror 06. The optical axis of the primary mirror 07 is consistent with the optical axis of the dichroic mirror 04.

[0035] Sample chamber 08 and primary mirror 07 are located on opposite sides of the integral unit consisting of secondary mirror 1 05 and secondary mirror 2 06, respectively; the sample to be tested is installed in sample chamber 08; and the sample to be tested is placed along the optical axis perpendicular to the primary mirror 07.

[0036] The excitation light emitted by laser 01 is split into two beams, which enter optical probe 1 02 and optical probe 2 03 respectively. The light emitted from optical probe 1 02 and optical probe 2 03 is transmitted through dichroic mirror 04 and then reflected by secondary mirror 1 05 and secondary mirror 2 06 respectively. The light reflected by secondary mirror 1 05 and secondary mirror 2 06 is then reflected by primary mirror 07 and focused onto the sample to be tested in sample chamber 08. The sample to be tested is excited to generate Raman scattered light. The Raman scattered light returns along the original optical path to optical probe 1 02 and optical probe 2 03, which collect the Raman scattered light and transmit it to the spectrometer host 010. The spectrometer host 010 transmits the raw spectral information of the Raman scattered light to computer 014. Computer 014 analyzes the sample to obtain the concentration information of the sample to be tested, thus completing the detection of the sample.

[0037] The dual optical probes (i.e., optical probe 1 02 and optical probe 2 03) enable the emission of excitation light and the collection of Raman scattered light. The dual optical probe design allows the system to collect Raman scattered light from different regions or angles simultaneously, and the position and angle of the dual optical probes can be adjusted according to actual needs.

[0038] The secondary mirror 05, secondary mirror 06, and primary mirror 07 together constitute a Cassegrain optical structure, which can simultaneously achieve focusing and imaging functions.

[0039] The Raman spectroscopy system also includes: a focusing objective lens 011, a CCD 012, a displacement stage 09, and a displacement stage controller 013;

[0040] The displacement stage 09 is installed at the bottom of the sample chamber 08 and can drive the sample chamber 08 to rotate and move up and down along the optical axis perpendicular to the main mirror 07.

[0041] The displacement stage controller 013 is used to control the movement of the displacement stage 09, secondary mirror 05, and secondary mirror 06.

[0042] The optical axis of the focusing objective 011 is perpendicular to the optical axis of the dichroic mirror 04; the CCD 012 and the dichroic mirror 04 are located on both sides of the focusing objective 011.

[0043] When using the imaging function of the Cassegrain optical structure, the Raman scattered light generated by the sample being excited returns along the original optical path to optical probe 1 02 and optical probe 2 03. After passing through dichroic mirror 04, it is reflected by dichroic mirror 04 to the focusing objective lens 011. The focusing objective lens 011 focuses the Raman scattered light and then it is incident on CCD 012. CCD 012 realizes the position of the sample and generates image information of the sample. CCD 012 detects the image information and feeds it back to computer 014. Computer 014 recognizes the image information to realize the position of the sample and feeds back the determined information to the displacement stage controller 013, which in turn controls the displacement stage 09 to realize the rotation of the sample chamber 08 and the up and down movement along the optical axis perpendicular to the main mirror 07.

[0044] When using the focusing function of the Cassegrain optical structure, the position of the focal point on the sample to be tested in the sample chamber 08 can be changed by adjusting the secondary mirror 05 and secondary mirror 06 through the displacement stage controller 013, so as to accurately focus the sample to be tested. At the same time, in conjunction with the position adjustment function of the displacement stage 09 (i.e., the rotation of the sample chamber 08 and the up and down movement along the optical axis perpendicular to the primary mirror 07), high-accuracy detection of the multi-point position of the sample to be tested can be achieved.

[0045] In this embodiment, see Appendix Figures 2-3 The sample chamber 08 is a polygonal cylindrical structure (the number of sides of the polygon can be determined according to the actual number of samples to be tested and the test time, etc.). The sample chamber 08 has multiple sample storage cavities corresponding to each side of the polygon. The top of the sample storage cavity is open, and the sample storage cavity stores the sample to be tested, which can be solid, liquid or gas. The side of the sample chamber 08 has multiple detection windows 081, which are connected to the multiple sample storage cavities. The laser reflected by the main mirror 07 enters through the detection window 081 and is focused on the sample to be tested.

[0046] Each sample receiving cavity includes a cylindrical cavity 083 and a rectangular plate cavity 082. The length directions of both the cylindrical cavity 083 and the rectangular plate cavity 082 are aligned with the length direction of the sample chamber 08. The plate surface of the rectangular plate cavity 082 is located on the side of the cylindrical cavity 083, and the rectangular plate cavity 082 communicates with the cylindrical cavity 083. The cylindrical cavity 083 is closer to the axis of the sample chamber 08 than the rectangular plate cavity 082, while the rectangular plate cavity 082 is closer to the detection window 081 than the cylindrical cavity 083. A focusing mirror 084 is glued to the inner wall surface of the cylindrical cavity 083 near the axis of the sample chamber 08. The focusing mirror 084 is used to focus and reflect the Raman scattered light.

[0047] When the sample to be tested is solid, the solid sample is placed inside the microfluidic chip, which is installed in the rectangular plate cavity 082; the microfluidic chip has a dynamic sample loading function, which can prevent the solid sample from floating in the air under microgravity environment;

[0048] When the sample to be tested is a liquid or a gas, the liquid / gas sample is placed in a round glass bottle, and the round glass bottle is installed in the cylindrical cavity 083;

[0049] Specifically, a microfluidic chip and a circular glass bottle cannot coexist in the same sample storage chamber; different sample storage chambers can store different test samples; when the test of one test sample is completed, the sample chamber 08 is automatically rotated by the displacement stage 09 to move to the next test sample, realizing continuous automatic measurement of the test sample in the sample chamber 08 and avoiding repeated installation of test samples; at the same time, the position of the sample chamber 08 can be automatically adjusted to avoid the problem of inaccurate testing caused by uneven sample distribution under microgravity environment, and can realize on-orbit testing.

[0050] In this embodiment, the laser 01 is a laser whose power and wavelength can be adjusted simultaneously. For the power adjustment part, the laser power used can be determined by the type of sample to be tested (gas, liquid, and solid). For the wavelength tuning part, the approximate spectral range is first determined by coarse measurement and fed back to the test software in the computer 014. The test software controls the laser 01 to automatically adjust the wavelength, thereby accurately matching the wavelength of the laser used and achieving high-accuracy detection of the characteristic peak curve of the sample to be tested.

[0051] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A Raman spectroscopy system based on a Cassegrain structure and dual optical probes, characterized in that, include: Laser, optical probe 1, optical probe 2, dichroic mirror, secondary mirror 1, secondary mirror 2, primary mirror, sample chamber, spectrometer main unit and computer; The excitation light emitted by the laser is split into two beams, which enter optical probe one and optical probe two, respectively. The light emitted from optical probe one and optical probe two is transmitted through a dichroic mirror and then reflected by secondary mirror one and secondary mirror two, respectively. The light reflected by secondary mirror one and secondary mirror two is then reflected by the primary mirror and focused onto the sample to be tested in the sample chamber. The sample to be tested is excited to produce Raman scattered light. The Raman scattered light returns along the original optical path to optical probe one and optical probe two, which collect the Raman scattered light and transmit it to the spectrometer host. The spectrometer host transmits the raw spectral information of the Raman scattered light to the computer. The computer analyzes the sample to obtain the concentration information of the sample, thus completing the detection of the sample. The dual optical probes, consisting of optical probe one and optical probe two, can realize the emission of excitation light and the collection of Raman scattered light; the Cassegrain optical structure, consisting of secondary mirror one, secondary mirror two, and primary mirror, can simultaneously realize focusing and imaging functions.

2. The Raman spectroscopy system based on a Cassegrain structure and dual optical probes as described in claim 1, characterized in that, The Raman spectroscopy system also includes: a focusing objective lens, a CCD, a shift stage, and a shift stage controller; The displacement stage is installed at the bottom of the sample chamber and can drive the sample chamber to rotate and move up and down along the optical axis perpendicular to the main mirror. The displacement stage controller is used to control the movement of the displacement stage, secondary mirror one, and secondary mirror two; When using the imaging function of the Cassegrain optical structure, the Raman scattered light generated by the sample being excited returns along the original optical path to optical probe one and optical probe two. After passing through the dichroic mirror, it is reflected by the dichroic mirror into the focusing objective. The focusing objective focuses the Raman scattered light and then it is incident on the CCD. The CCD realizes the position of the sample and generates image information of the sample. The CCD feeds the image information back to the computer. The computer recognizes the image information to realize the position of the sample and feeds the determined information back to the displacement stage controller, which then controls the displacement stage to realize the rotation of the sample chamber and the up and down movement along the optical axis perpendicular to the main mirror. When using the focusing function of the Cassegrain optical structure, the position of the focal point on the sample to be tested in the sample chamber can be changed by adjusting the secondary mirror one and secondary mirror two through the displacement stage controller, so as to accurately focus the sample to be tested. At the same time, in conjunction with the position adjustment function of the displacement stage, the multi-point position detection of the sample to be tested can be realized.

3. The Raman spectroscopy system based on a Cassegrain structure and dual optical probes as described in claim 2, characterized in that, The sample chamber is a polygonal cylindrical structure. The sample chamber has multiple sample storage cavities corresponding to each side of the polygon. The top of the sample storage cavity is open. The sample storage cavity stores the sample to be tested, which can be solid, liquid or gas. The side of the sample chamber has multiple detection windows, which are connected to the multiple sample storage cavities. The laser reflected by the primary mirror enters through the detection windows and is focused on the sample to be tested. Each sample receiving cavity includes a cylindrical cavity and a rectangular plate cavity. The length directions of the cylindrical cavity and the rectangular plate cavity are both aligned with the length direction of the sample chamber. The plate surface of the rectangular plate cavity is located on the side of the cylindrical cavity, and the rectangular plate cavity is connected to the cylindrical cavity. The cylindrical cavity is closer to the axis of the sample chamber than the rectangular plate cavity, and the rectangular plate cavity is closer to the detection window than the cylindrical cavity. When the sample to be tested is solid, the solid sample is placed inside the microfluidic chip, which is installed in a rectangular plate cavity; When the sample to be tested is a liquid or a gas, the liquid / gas sample is placed in a round glass bottle, which is installed in a cylindrical cavity.

4. The Raman spectroscopy system based on a Cassegrain structure and dual optical probes as described in claim 3, characterized in that, A focusing mirror is glued to the inner wall of the cylindrical cavity near the axis of the sample chamber. The focusing mirror is used to achieve focused reflection of Raman scattered light.

5. The Raman spectroscopy system based on a Cassegrain structure and dual optical probes as described in claim 3, characterized in that, A microfluidic chip and a circular glass bottle cannot coexist in the same sample storage chamber; different sample storage chambers can store different test samples; when the test of a test sample is completed, the sample chamber is rotated automatically by the displacement stage to move to the next test sample, so as to realize the continuous automatic measurement of the test sample in the sample chamber.

6. A Raman spectroscopy system based on a Cassegrain structure and dual optical probes as described in any one of claims 1-5, characterized in that, The laser is a laser whose power and wavelength can be adjusted simultaneously.

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