Laser-induced fluorescence spectrum detection structure

Abstract

The utility model discloses a laser-induced fluorescence spectrum detection structure, which comprises a laser generating mechanism, a spectrum collecting and analyzing mechanism and a cylindrical target material, the laser generating mechanism comprises a fixed laser and a focusing lens, and the spectrum collecting and analyzing mechanism comprises a collecting lens, an optical fiber and a spectrograph; the target material is vertically arranged on the rotating platform and horizontally rotates along with the rotating platform, and the vertical axis of the rotating platform and the vertical axis of the target material are located on the same straight line; the laser generating mechanism is arranged on one side of the rotating platform so that pulse laser generated by the laser generating mechanism can bombard the outer circumferential side face of the target material in the radial direction of the target material, and the bombarded position of the outer circumferential side face of the target material can generate a fluorescence spectrum. And the spectrum collection and analysis mechanism is used for collecting the fluorescence spectrum and analyzing and processing the fluorescence spectrum. According to the utility model, the relative stability of the laser beam and the target material can be improved, the spectral intensity and the spectral collection efficiency are improved, and the influence of incident light on the collected spectrum is reduced.

Description

Technical Field

[0001] The utility model belongs to the technical field of detection, relates to a laser induced fluorescence spectrum detection device, and particularly relates to a laser induced fluorescence spectrum detection structure. Background Art

[0002] Laser induced fluorescence spectroscopy (LIF) detection device is a highly sensitive detection technology, widely used in biology, chemistry and medicine, and is one of the main detection methods for measuring trace elements and non-destructive testing. LIF detection technology focuses pulsed laser to reach a certain power density, further bombards and excites the target material (gas, liquid, solid), thereby reaching the detection limit and performing qualitative and quantitative analysis on the target material.

[0003] However, the laser induced fluorescence spectroscopy (LIF) detection device in the prior art (such as CN 218157555 U) generally has a low efficiency in collecting de-excited fluorescence scattered light generated by LIF, resulting in low spectral resolution, which makes it impossible to accurately distinguish characteristic peaks with weak intensity, resulting in the loss of some useful information. At the same time, two motors move on the XY plane. Due to the large vibration of the two motors, the relative stability of the laser beam and the target material is affected, thereby affecting the measurement stability and reliability. At the same time, the existing target material is in a relatively thin cylindrical shape (circular sheet) and is made by a tablet press. After tableting, due to the structural structure of the cylindrical tablet press, the outer circumferential side of the target material is smoother and flatter than the upper and lower surfaces of the target material. The existing laser bombards the upper and lower surfaces of the target material (tablet press) to analyze the target material, which will cause jitter during the movement, thereby having a certain impact on the spectral resolution. Summary of the invention

[0004] In view of the above-mentioned deficiencies in the prior art, the purpose of the present invention is to provide a laser induced fluorescence spectrum detection structure, which can improve the relative stability of the laser beam and the target material, improve the spectrum intensity, spectrum collection efficiency and reduce the influence of incident light on the collected spectrum.

[0005] The technical solution of the utility model is achieved in this way:

[0006] A laser induced fluorescence spectrum detection structure comprises a laser generating mechanism, a spectrum collecting and analyzing mechanism and a cylindrical target material. The laser generating mechanism comprises a fixed laser and a focusing lens, and the spectrum collecting and analyzing mechanism comprises a collecting lens, an optical fiber and a spectrometer.

[0007] The target material is vertically arranged on a rotating platform and rotates horizontally with the rotating platform, and the vertical axes of the rotating platform and the target material are located in the same straight line; the laser generating mechanism is arranged on one side of the rotating platform so that the pulsed laser generated by the laser generating mechanism bombards the outer circumferential side surface of the target material along the radial direction of the target material, so that the position where the outer circumferential side surface of the target material is bombarded produces a fluorescence spectrum; the spectrum collection and analysis mechanism is used to collect the fluorescence spectrum and analyze it.

[0008] Furthermore, a rotating motor is provided below the rotating platform, and the rotating motor is coaxially arranged with the rotating platform, so that the rotating platform can be driven to rotate at a uniform speed by the rotating motor.

[0009] Furthermore, the rotating motor is a stepping motor.

[0010] Furthermore, a positioning laser is provided above the rotating platform to make the center of the target material coincide with the laser point of the positioning laser, so that the vertical axis of the target material and the rotating platform are located in the same straight line.

[0011] Compared with the prior art, the utility model has the following beneficial effects:

[0012] 1. The pulsed laser generated by the laser generating mechanism bombards the target material's relatively smooth outer circumferential surface. At the same time, the target material rotates horizontally with the rotating platform, and the radius of the target material is fixed. Therefore, during the rotation process, the target material bombardment point and the pulsed laser optical path are fixed, so that each laser pulse can always bombard a fresh point on the side of the target material, ensuring that each excitation point and the pulsed laser optical path are as consistent as possible, thereby effectively reducing the error caused by the slight change in the distance between the incident pulsed laser and the target material surface when exciting fluorescence, improving the relative stability of the laser beam and the target material, and then improving the spectral intensity, spectral collection efficiency and reducing the impact of the incident spectrum on the collected spectrum.

[0013] 2. Compared with CN 218157555 U which moves on the XY plane through two motors, the utility model adopts a rotary motor to drive the rotary platform to rotate, thereby greatly reducing the errors caused by inherent factors such as motor vibration, further improving the relative stability of the laser beam and the target material, improving the spectral intensity and spectral collection efficiency, and reducing the impact of the incident spectrum on the collected spectrum. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 -Structural schematic diagram of the utility model.

[0015] Among them: 1-rotating motor; 2-rotating platform; 3-target material; 4-positioning laser; 5-collecting lens; 6-optical fiber; 7-spectrometer; 8-fixed laser; 9-focusing lens. DETAILED DESCRIPTION

[0016] The utility model is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0017] See also Figure 1 A laser-induced fluorescence spectrum detection structure includes a laser generating mechanism, a spectrum collecting and analyzing mechanism and a cylindrical target material 3, wherein the laser generating mechanism includes a fixed laser 8 and a focusing lens 9, wherein the fixed laser can generate pulsed laser, and the focusing lens 9 is arranged between the fixed laser 8 and the target material 3 for focusing the pulsed laser to bombard the target material, and a fluorescence spectrum will be generated after bombarding the target material; the spectrum collecting and analyzing mechanism includes a collecting lens 5, an optical fiber and a spectrometer 7, wherein the optical fiber 6 is arranged at the focus of the collecting lens 5, and the collecting lens 5 collects the fluorescence spectrum and transmits it to the spectrometer 7 through the optical fiber 5 for related analysis and processing.

[0018] The target material 3 is vertically arranged on the rotating platform 2 and rotates horizontally with the rotating platform 2, and the vertical axes of the rotating platform 2 and the target material 3 are located in the same straight line; the laser generating mechanism is arranged on one side of the rotating platform 2 so that the pulsed laser generated by the laser generating mechanism bombards the outer circumferential side surface of the target material 3 radially along the target material 3, so that the position where the outer circumferential side surface of the target material 3 is bombarded produces a fluorescence spectrum; the spectrum collection and analysis mechanism is used to collect the fluorescence spectrum and analyze it.

[0019] In this way, the pulse laser generated by the laser generating mechanism bombards the relatively smooth outer circumferential surface of the target material. At the same time, the target material rotates horizontally with the rotating platform, and the radius of the target material is fixed. Then, during the rotation process, the bombardment point of the target material and the pulse laser optical path are fixed, so that each laser pulse can always bombard a fresh point on the side of the target material, ensuring that each excitation point and the pulse laser optical path are as consistent as possible, thereby effectively reducing the error caused by slight changes in the distance between the incident pulse laser and the target material surface when exciting fluorescence, improving the relative stability of the laser beam and the target material, and thereby improving the spectral intensity, spectral collection efficiency and reducing the influence of the incident spectrum on the collected spectrum.

[0020] In specific implementation, a rotating motor 1 is provided below the rotating platform 2, and the rotating motor 1 is coaxially arranged with the rotating platform 2, so that the rotating platform 2 can be driven to rotate at a constant speed by the rotating motor 1. In this embodiment, the rotating motor 1 is a stepping motor.

[0021] Here, a rotating motor is used to drive the rotating platform to rotate. Compared with CN 218157555 U which uses two motors to move on the XY plane, the utility model has higher stability and reliability, thereby greatly reducing the errors caused by inherent factors such as stepper motor vibration, further improving the relative stability of the laser beam and the target material, improving the spectral intensity and spectral collection efficiency, and reducing the influence of the incident spectrum on the collected spectrum.

[0022] In a specific implementation, a positioning laser 4 is provided above the rotating platform 2 so that the center of the target 3 and the laser point of the positioning laser 4 coincide with each other, thereby making the vertical axes of the target 3 and the rotating platform 2 located in the same straight line.

[0023] When installing the rotating platform, the laser of the positioning laser is directed vertically downward toward the center of the rotating platform, and then the target is fixed on the rotating platform and the center of the target coincides with the laser point of the positioning laser, thereby ensuring that the target and the axis of the rotating platform coincide (are located on the same straight line). In this way, the positioning laser is used to position the rotating platform and the target, which can further effectively reduce the error caused by the slight change in the distance between the incident pulse laser and the target surface when exciting fluorescence, improve the relative stability of the laser beam and the target, and thus improve the spectral intensity, spectral collection efficiency, and reduce the impact of the incident spectrum on the collected spectrum.

[0024] Finally, it should be noted that the above embodiments of the present invention are only examples for illustrating the present invention, and are not intended to limit the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes and modifications can be made based on the above description. It is impossible to list all implementation methods here. Any obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. A laser induced fluorescence spectrum detection structure, comprising a laser generating mechanism, a spectrum collecting and analyzing mechanism and a cylindrical target material, wherein the laser generating mechanism comprises a fixed laser and a focusing lens, and the spectrum collecting and analyzing mechanism comprises a collecting lens, an optical fiber and a spectrometer; characterized in that: The target material is vertically arranged on a rotating platform and rotates horizontally with the rotating platform, and the vertical axes of the rotating platform and the target material are located in the same straight line; the laser generating mechanism is arranged on one side of the rotating platform so that the pulsed laser generated by the laser generating mechanism bombards the outer circumferential side surface of the target material along the radial direction of the target material, so that the position where the outer circumferential side surface of the target material is bombarded produces a fluorescence spectrum; the spectrum collection and analysis mechanism is used to collect the fluorescence spectrum and analyze it.

2. A laser induced fluorescence spectrum detection structure according to claim 1, characterized in that: A rotating motor is provided below the rotating platform, and the rotating motor is coaxially arranged with the rotating platform, so that the rotating platform can be driven to rotate at a uniform speed by the rotating motor.

3. A laser induced fluorescence spectrum detection structure according to claim 2, characterized in that: The rotating motor is a stepping motor.

4. A laser induced fluorescence spectrum detection structure according to claim 1, 2 or 3, characterized in that: A positioning laser is arranged above the rotating platform to make the center of the target material coincide with the laser point of the positioning laser, so that the vertical axis of the target material and the rotating platform are located in the same straight line.

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