Raman laser capable of preventing burnout of sample

Abstract

The utility model relates to a Raman laser capable of preventing burnout of a sample. The Raman laser comprises a laser, a collimating mirror, a galvanometer, a dichroscope, a probe tube, a first focus lens, a second focus lens and a Raman signal receiving end. The laser device emits laser, the laser is changed into first parallel light through the collimating mirror to irradiate the galvanometer, the galvanometer is arranged in a swinging mode and reflects the first parallel light passing through the collimating mirror to the dichroscope, the dichroscope reflects the first parallel light reflected by the galvanometer to the probe tube, the first focusing mirror focuses the first parallel light passing through the probe tube to a sample, and the second focusing mirror focuses the first parallel light passing through the probe tube to the sample. Light scattered on the sample returns reversely and becomes second parallel light through the first focus lens, the second parallel light can penetrate through the dichroscope after passing through the probe tube, and the second focus lens focuses the second parallel light penetrating through the dichroscope to the Raman signal receiving end. Point-shaped light spots focused on a sample continuously swing through the galvanometer, so that energy is uniformly dispersed, and the phenomenon that the sample is burnt due to the fact that the light spots are kept at the same position for a long time is avoided.

Description

Technical Field

[0001] The utility model relates to the field of Raman lasers, in particular to a Raman laser capable of preventing samples from being burned. Background Art

[0002] Raman detection refers to the scattering of light when it is irradiated on a substance. In addition to the elastic component with the same frequency as the excitation light, the scattered light also has components with different frequencies from the excitation light. The former are collectively called Rayleigh lines and the latter are collectively called Raman lines. The inelastic scattering caused by the interaction between the molecular vibration, optical phonons in the solid and the excitation light is called Raman scattering. Generally, the spectrum formed by combining Rayleigh scattering and Raman scattering is called Raman spectrum.

[0003] Raman lasers are based on stimulated Raman scattering, which can produce wavelengths that solid lasers cannot directly emit. Its basic components are high-pressure gas photoelectric boxes and resonant cavity optical devices. Raman lasers sometimes require 500mW or even higher laser powers for Raman detection. High-power lasers generate high energy. After the Raman laser is focused, irradiating dark samples will cause the samples to burn and be destroyed directly. Using defocusing to reduce energy density, the Raman signal will be greatly attenuated, and even the Raman signal cannot be measured. Utility Model Content

[0004] The utility model aims to provide a Raman laser which can prevent samples from being burned, so as to solve the problem that high-power laser irradiation on dark samples may cause the samples to be burned.

[0005] In order to solve the above technical problems, the utility model adopts the following technical solutions.

[0006] The utility model provides a Raman laser for preventing samples from being burned, which comprises: a laser, a collimating mirror, a galvanometer, a dichroic mirror, a probe tube, a first focusing mirror, a second focusing mirror and a Raman signal receiving end;

[0007] The laser emits a laser and is converted into a first parallel light through the collimator to irradiate the galvanometer. The galvanometer is swingably arranged and reflects the first parallel light passing through the collimator to the dichroic mirror. The dichroic mirror reflects the first parallel light reflected by the galvanometer to the probe tube. The first focusing mirror focuses the first parallel light passing through the probe tube onto the sample. The light scattered on the sample returns in the reverse direction and is converted into a second parallel light through the first focusing mirror. The second parallel light can pass through the dichroic mirror after passing through the probe tube. The second focusing mirror focuses the second parallel light passing through the dichroic mirror onto the Raman signal receiving end.

[0008] In some embodiments of the present application, the laser, the collimating mirror and the galvanometer are arranged in sequence and spaced apart in a first straight line direction, the Raman signal receiving end, the second focusing mirror, the dichroic mirror, the probe tube and the first focusing mirror are arranged in sequence and spaced apart in a second straight line direction, and the first straight line and the second straight line are arranged in parallel and spaced apart.

[0009] In some embodiments of the present application, the galvanometer is a two-dimensional galvanometer, and the galvanometer can swing in the up-down direction and the left-right direction, so that the trajectory of the first parallel light reflected by the galvanometer is rectangular.

[0010] In some embodiments of the present application, the galvanometer is a one-dimensional galvanometer, and the galvanometer can swing in the up-down direction or the left-right direction so that the trajectory of the first parallel light reflected by the galvanometer is in a straight line.

[0011] It can be seen from the above technical solutions that the embodiments of the utility model have at least the following advantages and positive effects:

[0012] In the Raman laser for preventing the sample from being burned in the embodiment of the utility model, the first parallel light reflected by the galvanometer is also in a swinging state through the swing of the galvanometer. After the swinging first parallel light passes through the dichroic mirror and the probe tube, it is focused on the sample through the first focusing mirror. The point-shaped light spot focused on the sample will continuously swing on the surface of the sample, thereby evenly dispersing the energy and preventing the point-shaped light spot from being kept at the same position of the sample for a long time, causing the sample to be burned. In addition, since the light spot focused on the sample is still a point-shaped light spot, rather than a planar light spot formed after defocusing, there is no energy loss and the intensity of the Raman signal is not affected.

[0013] Of course, the second parallel light formed by the light dissipated by the sample after passing through the first focusing mirror also swings, so it is focused by the second focusing mirror and then received by the Raman signal receiving end. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The various objects, features and advantages of the present invention will become more apparent by considering the following detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. The accompanying drawings are only exemplary illustrations of the present invention and are not necessarily drawn to scale. In the accompanying drawings, the same reference numerals always represent the same or similar parts. Among them:

[0015] Figure 1 is a schematic structural diagram of a Raman laser for preventing burning of samples according to an exemplary embodiment.

[0016] Figure 2 is a side view of a galvanometer according to an exemplary embodiment.

[0017] Figure 3is a top view of a galvanometer according to an exemplary embodiment.

[0018] The description of the accompanying drawings is as follows: 1. Laser; 2. Collimating mirror; 3. Galvanometer; 4. Dichroic mirror; 5. Probe tube; 6. First focusing mirror; 7. Second focusing mirror; 8. Raman signal receiving end. DETAILED DESCRIPTION

[0019] Although the present invention can be easily embodied as embodiments of different forms, only some of the specific embodiments are shown in the drawings and described in detail in this specification. It should be understood that this description should be regarded as an exemplary description of the principles of the present invention and is not intended to limit the present invention to that described herein.

[0020] Thus, a feature indicated in this specification will be used to illustrate one of the features of an embodiment of the utility model, rather than implying that each embodiment of the utility model must have the described feature. In addition, it should be noted that this specification describes many features. Although some features can be combined together to illustrate possible system designs, these features can also be used in other combinations that are not explicitly described. Thus, unless otherwise stated, the described combinations are not intended to be limiting.

[0021] In the embodiments shown in the drawings, the indications of directions (such as up, down, left, right, front and back) used to explain the structure and movement of various elements of the utility model are not absolute but relative. These descriptions are appropriate when these elements are in the positions shown in the drawings. If the descriptions of the positions of these elements change, the indications of these directions also change accordingly.

[0022] See also Figures 1 to 3 A Raman laser 1 for preventing a sample from being burned provided by an embodiment of the utility model comprises a laser 1, a collimating mirror 2, a galvanometer 3, a dichroic mirror 4, a probe tube 5, a first focusing mirror 6, a second focusing mirror 7 and a Raman signal receiving end 8.

[0023] The laser 1 emits a laser and is converted into a first parallel light through a collimator 2 to irradiate a galvanometer 3. The galvanometer 3 is swingably arranged and reflects the first parallel light passing through the collimator 2 to a dichroic mirror 4. The dichroic mirror 4 reflects the first parallel light reflected by the galvanometer 3 to a probe tube 5. The first focusing mirror 6 focuses the first parallel light passing through the probe tube 5 onto a sample. The light scattered on the sample returns in the reverse direction and is converted into a second parallel light through the first focusing mirror 6. The second parallel light can pass through the dichroic mirror 4 after passing through the probe tube 5. The second focusing mirror 7 focuses the second parallel light passing through the dichroic mirror 4 onto a Raman signal receiving end 8.

[0024] Through the swing of the galvanometer 3, the first parallel light reflected by the galvanometer 3 is also in a swinging state. After passing through the dichroic mirror 4 and the probe tube 5, the swinging first parallel light is focused on the sample through the first focusing mirror 6. The point-shaped light spot focused on the sample will continuously swing on the surface of the sample, thereby evenly dispersing the energy and preventing the point-shaped light spot from being kept at the same position of the sample for a long time, causing the sample to be burned. And because the light spot focused on the sample is still a point-shaped light spot, rather than a planar light spot formed after defocusing, there is no energy loss and the intensity of the Raman signal is not affected.

[0025] Of course, the second parallel light formed by the light dissipated by the sample after passing through the first focusing mirror 6 also oscillates, so it is focused by the second focusing mirror 7 and then received by the Raman signal receiving end 8 .

[0026] Among them, defocus means that the focus is located on the front or back side of the sample surface, so the light spot formed is a planar light spot. Although it can avoid the problem of the sample surface being too concentrated and causing the sample to be burned, the defocusing method is used to reduce the energy density. At this time, the Raman signal will be greatly attenuated, or even the Raman signal cannot be measured directly.

[0027] When encountering dark samples in related technologies, there is also a way to avoid sample burning by reducing the laser power and increasing the integration time. However, this method wastes a lot of time. After reducing the power, the detection time will increase by dozens of times or even dozens of times on the original basis. For some substances, the Raman signal cannot be detected when the excitation power is insufficient.

[0028] The working principle of the galvanometer 3 is as follows: MEMS (micro-electromechanical system) technology is adopted. By arranging a magnet under the galvanometer 3, the current flowing in the coil around the galvanometer 3 generates a Lorentz force that drives the galvanometer 3 based on Fleming's law, thereby changing the deflection angle of the galvanometer 3.

[0029] The galvanometer 3 may be a two-dimensional galvanometer 3, and the galvanometer 3 can swing in the up-down direction and the left-right direction, so that the trajectory of the first parallel light reflected by the galvanometer 3 is rectangular. Since the frequency of the galvanometer 3 swinging is very high, the light spot seen by the naked eye on the sample surface is a rectangular light spot. The specific swinging sequence of the galvanometer 3 includes but is not limited to swinging back and forth up, right, down, left, and then up, drawing a rectangular trajectory. Figure 2 The 2D galvanometer mirror 3 is shown in a side view and can be swung within swiveling angles A1 and A2 . Figure 3 The 2D galvanometer mirror 3 is shown in a side view and can be swung within swiveling angles B1 and B2 .

[0030] The galvanometer 3 may also be a one-dimensional galvanometer 3, and the galvanometer 3 can swing in the up-down direction or the left-right direction, so that the trajectory of the first parallel light reflected by the galvanometer 3 is straight. The light spot seen by the naked eye on the sample surface is a straight light spot. The specific swinging sequence of the galvanometer 3 includes but is not limited to swinging back and forth up, down, and then up, or swinging back and forth left, right, and then right.

[0031] It should be noted that, although the point-shaped light spot focused on the sample will continuously swing on the surface of the sample, the light path is reversible, so the light scattered on the sample will still return to the first focusing mirror 6 .

[0032] The laser 1, collimating mirror 2 and galvanometer 3 are arranged in sequence and spaced apart in the first straight line direction, the Raman signal receiving end 8, the second focusing mirror 7, the dichroic mirror 4, the probe tube 5 and the first focusing mirror 6 are arranged in sequence and spaced apart in the second straight line direction, and the first straight line and the second straight line are arranged in parallel and spaced apart.

[0033] The working principle of the dichroic mirror 4 is: it almost completely transmits light of a certain wavelength, and almost completely reflects light of other wavelengths. The wavelength of the light scattered by the sample, i.e., the second parallel light, is greater than the wavelength of the laser light emitted by the laser 1, i.e., the first parallel light. The dichroic mirror 4 is configured to completely reflect the first parallel light with a shorter wavelength, and completely transmit the second parallel light with a longer wavelength.

[0034] Although the utility model has been described with reference to several typical embodiments, it should be understood that the terms used are illustrative and exemplary, rather than restrictive. Since the utility model can be implemented in a variety of forms without departing from the spirit or essence of the utility model, it should be understood that the above-mentioned embodiments are not limited to any of the aforementioned details, but should be widely interpreted within the spirit and scope defined by the attached claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the attached claims.

Claims

1. A Raman laser for preventing burning of samples, characterized in that: include: Laser, collimator, galvanometer, dichroic mirror, probe tube, first focusing mirror, second focusing mirror and Raman signal receiving end; The laser emits a laser and is converted into a first parallel light through the collimator to irradiate the galvanometer. The galvanometer is swingably arranged and reflects the first parallel light passing through the collimator to the dichroic mirror. The dichroic mirror reflects the first parallel light reflected by the galvanometer to the probe tube. The first focusing mirror focuses the first parallel light passing through the probe tube onto the sample. The light scattered on the sample returns in the reverse direction and is converted into a second parallel light through the first focusing mirror. The second parallel light can pass through the dichroic mirror after passing through the probe tube. The second focusing mirror focuses the second parallel light passing through the dichroic mirror onto the Raman signal receiving end.

2. The Raman laser for preventing sample burning according to claim 1, characterized in that: The laser, the collimating mirror and the galvanometer are arranged in sequence and spaced apart in the first straight line direction, the Raman signal receiving end, the second focusing mirror, the dichroic mirror, the probe tube and the first focusing mirror are arranged in sequence and spaced apart in the second straight line direction, and the first straight line and the second straight line are arranged in parallel and spaced apart.

3. The Raman laser for preventing sample burning according to claim 1, characterized in that: The galvanometer is a two-dimensional galvanometer, and the galvanometer can swing in the up-down direction and the left-right direction, so that the trajectory of the first parallel light reflected by the galvanometer is rectangular.

4. The Raman laser for preventing sample burning according to claim 1, characterized in that: The galvanometer is a one-dimensional galvanometer, and the galvanometer can swing in an up-and-down direction or a left-and-right direction, so that the trajectory of the first parallel light reflected by the galvanometer is in a straight line.

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