Laser wavelength calibration device based on optical fiber light leakage

Abstract

The utility model provides a laser wavelength calibration device based on optical fiber light leakage. The laser wavelength calibration device comprises an optical fiber bending assembly, a condensation assembly, a reference gas chamber, a detector assembly and a circuit board assembly, the optical fiber bending assembly is internally provided with a mechanism for locally bending the optical fiber, so that the optical fiber leaks light at the bending part to form a light leakage light source; the condensation assembly is arranged corresponding to the position of the light leakage source and is used for converging the leaked light; the front end of the reference gas chamber is arranged corresponding to an output light path of the light gathering assembly and is used for enabling the gathered light to pass through the reference gas chamber; the detector assembly is arranged at the rear end of the reference gas chamber and is used for collecting light penetrating through the reference gas chamber and converting the light into an electric signal; the circuit board assembly is connected with the detector assembly and used for processing the received electric signals and obtaining harmonic information of gas in the reference gas chamber to serve as reference information for calibrating laser parameters. The device has the advantages.

Description

Technical Field

[0001] This utility model relates to the field of gas sensor calibration technology, specifically to a laser wavelength calibration device based on fiber optic leakage. Background Technology

[0002] In the field of tunable semiconductor laser absorption spectroscopy for gas detection, gas concentration detection equipment generally includes a laser, a gas chamber, and a detector assembly. The laser emits light that covers the absorption peak of the target gas, which is absorbed by the target gas in the gas chamber and converted into an analog electrical signal by the detector assembly. The electrical signal is then used to calculate the concentration of the target gas through techniques such as lock-in amplification.

[0003] Laser wavelengths can drift due to factors such as circuit noise and external environment, leading to measurement errors. Currently, laser wavelength calibration technology uses optical devices (such as fiber optic splitters) to split the laser beam. One beam passes through a detection chamber and illuminates the main detector assembly, while the other beam passes through a sealed chamber containing the target gas and illuminates a reference detector assembly. The laser wavelength is calibrated by extracting the harmonic information of the target gas in the reference chamber. For example, the technical solution with application number CN202111159898.3, entitled "An Automatic Calibration Method for an Open-Circuit Laser Gas Detection Device," belongs to this category.

[0004] However, the problem is that lasers and fiber optic splitters, as well as fiber optic collimators, are all connected via fiber optic flanges. This results in numerous link connectors, leading to high optical noise. Furthermore, the fiber optic cables need to be coiled, resulting in a large size, which is not conducive to large-scale applications.

[0005] To reduce the number of link connectors while ensuring system stability, a new calibration device needs to be developed to replace traditional calibration methods. Utility Model Content

[0006] The purpose of this invention is to address the shortcomings of existing technologies by providing a laser wavelength calibration device based on fiber optic leakage light that reduces link joints, simplifies the detection method, and improves detection stability.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is: a laser wavelength calibration device based on fiber optic leakage, comprising a fiber bending assembly, a focusing assembly, a reference gas chamber, a detector assembly, and a circuit board assembly.

[0008] The optical fiber bending assembly is provided with a mechanism for locally bending the optical fiber, so that light leaks out at the bend, forming a light leakage source.

[0009] The light-concentrating component is positioned corresponding to the location of the light-leaking source and is used to concentrate the leaked light.

[0010] The front end of the reference gas cell is set to correspond to the output optical path of the focusing component, so that the focused light passes through the reference gas cell;

[0011] The detector assembly is located at the rear end of the reference gas cell and is used to collect light passing through the reference gas cell and convert it into an electrical signal;

[0012] The circuit board assembly is connected to the detector assembly and is used to process the received electrical signals and acquire the harmonic information of the gas in the reference chamber as reference information for calibrating the laser parameters.

[0013] Based on the above, it also includes a base, on which the fiber bending assembly, focusing assembly, reference gas chamber, detector assembly and circuit board assembly are all disposed.

[0014] Based on the above, the fiber bending assembly, focusing assembly, reference gas chamber, detector assembly, and circuit board assembly are arranged and distributed along the same central axis based on the base.

[0015] Based on the above, the fiber bending assembly is integrally integrated into the front end of the base, and a cavity is provided in the base. The front end of the cavity is connected to the light leakage source of the fiber bending assembly. The focusing assembly is installed at the front end of the cavity and close to the light leakage source through a pressure ring. The reference gas chamber is an independent gas chamber, installed in the cavity and located behind the pressure ring. The detector assembly and the circuit board assembly are sealed at the rear end of the cavity.

[0016] Based on the above, the fiber bending assembly is integrally integrated into the front end of the base, and the base is provided with a cavity that is only open at the front and rear ends. The front end of the cavity is connected to the light leakage source of the fiber bending assembly. The focusing assembly is installed at the front end of the cavity near the light leakage source by means of a pressure ring, and the focusing assembly, together with the pressure ring, seals the front end of the cavity. The detector assembly and the circuit board assembly are encapsulated in the rear end of the cavity and seal the rear end of the cavity. The reference gas chamber is formed in the middle of the cavity.

[0017] Based on the above, a cavity is provided in the base, and the focusing component and the detector component are sealed and installed at both ends of the focusing component fixing component to form the reference gas chamber; the fiber bending component is integrally integrated into the front end of the base, and the light leakage source of the fiber bending component is directly facing the position of the focusing component.

[0018] Based on the above, the light-concentrating component is a lens or a condenser lens.

[0019] Based on the above, the fiber bending assembly includes a groove with a predetermined curve.

[0020] Based on the above, the fiber bending assembly includes a concave arc surface formed on the front end of the base and a slider with an outward convex arc surface corresponding to the concave arc surface. The bending angle is adjusted by adjusting the distance between the outward convex arc surface and the concave arc surface of the slider.

[0021] Based on the above, the circuit board assembly is a circuit board that integrates a microprocessor and peripheral circuits.

[0022] This utility model has substantial features and progress compared to the prior art. Specifically, this utility model has the following advantages:

[0023] This solution eliminates the need for additional link structures and reduces the use of link connectors. Utilizing the principle that optical fibers easily leak light at bends, a fiber optic bending assembly is installed, causing the main link's fiber to pass through this point and leak light. The leaked light serves as the light source for the reference optical path. A corresponding focusing assembly is configured to concentrate the leaked light and guide it into a reference gas chamber. The reference gas chamber is filled with standard gas, and a detector assembly collects the light passing through it. After processing, the harmonic information of the reference gas chamber is obtained, which can be used as reference information to determine whether the laser wavelength in the main link is within a reasonable range. Based on this information, the staff adjusts the laser parameters to complete the laser wavelength calibration.

[0024] This solution does not modify the original optical path structure, the link connector is significantly reduced compared to traditional solutions, and the detection method is extremely simple. It can be manufactured and applied on a large scale, and existing equipment that has already been installed can be used directly. The stability of the detection is also relatively guaranteed. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the laser wavelength calibration device based on fiber optic leakage light in Embodiment 1 of this utility model.

[0026] Figure 2 This is a schematic diagram of the laser wavelength calibration device based on fiber optic leakage light in Embodiment 2 of this utility model.

[0027] Figure 3 This is a schematic diagram of the laser wavelength calibration device based on fiber optic leakage light in Embodiment 3 of this utility model.

[0028] Figure 4 This is a schematic diagram of the optical fiber bending assembly in Embodiment 4 of this utility model.

[0029] In the diagram: 1. Laser; 2. Base; 3. Focusing assembly; 4. Pressure ring; 5. Reference gas chamber; 6. Detector assembly; 7. Circuit board assembly; 8. Optical fiber; 9. Optical fiber bending assembly; 10. Focusing assembly fixing component. Detailed Implementation

[0030] The technical solution of this utility model will be further described in detail below through specific embodiments.

[0031] Example 1

[0032] like Figure 1 As shown, a laser wavelength calibration device based on fiber optic leakage includes a fiber bending assembly 9, a focusing assembly 3, a reference gas chamber 5, a detector assembly 6, and a circuit board assembly 7. In this embodiment, the above-mentioned components are installed on the same base 2, and a cavity is opened in the base 2. The fiber bending assembly, focusing assembly 3, reference gas chamber 5, detector assembly 6, and circuit board assembly 7 are arranged and distributed along the same central axis based on the cavity in the base.

[0033] The fiber bending assembly is provided with a mechanism for locally bending the fiber to cause light leakage at the bend. In this embodiment, the fiber bending assembly is designed as a groove with a set curve, located at the front end of the base 2. The fiber of the main link of the laser 1 is partially inserted into the groove to form a bending structure, and light leakage occurs at the bend, forming a light leakage source. The front end of the cavity is connected to the light leakage source of the fiber bending assembly to form a stepped hole.

[0034] The light-concentrating component 3 is set at the location of the light leakage source and is used to converge the leaked light. In this embodiment, the light-concentrating component 3 is a lens and is fixed by a pressure ring 4 pressing and installing it at the stepped hole at the front end of the cavity. The light leakage source is converged by the light-concentrating component 3 to form a beam splitting optical path, which is equivalent to a reference optical path in the traditional sense.

[0035] In other embodiments, the focusing component 3 may also employ other types of focusing lenses.

[0036] The front end of the reference chamber 5 is set to correspond to the output optical path of the focusing component, so that the focused light passes through the reference chamber 5. In this embodiment, the reference chamber 5 is set as an independent structure. It is a closed cavity filled with standard gas, installed in the cavity and located behind the pressure ring. The optical path output by the focusing component enters from the front end of the reference chamber and exits from the rear end.

[0037] The detector assembly 6 is located at the rear end of the reference gas chamber 5 and is used to collect light passing through the reference gas chamber 5 and convert it into an electrical signal. It is a traditional detector, such as a photoelectric detector assembly.

[0038] The circuit board assembly 7 is connected to the detector assembly 6 and is used to process the received electrical signals and obtain the harmonic information of the gas in the reference gas chamber as reference information for calibrating the laser parameters. The circuit board assembly 7 is a circuit board with integrated functional components, including a microprocessor and peripheral circuits, and is installed at the rear end of the cavity to seal the cavity.

[0039] Working principle explanation:

[0040] By adjusting and controlling the operating current and operating temperature of laser 1, laser 1 emits light containing the absorption peak wavelength of the gas "fingerprint". The light is transmitted through optical fiber 8. When the optical fiber passes through the optical fiber bending assembly, it is bent, causing light leakage. The leaked light is focused by the focusing assembly 3 fixed by the pressure ring 4, and then shines on the detector assembly 6 through the reference gas chamber 5 which is sealed with a certain concentration of the target gas to be tested. The detector assembly converts the light into an electrical signal. After the electrical signal passes through the filter amplification circuit and the lock-in amplification circuit in the circuit board assembly 7 and is processed by the relevant program, the harmonic information of the target gas in the reference gas chamber is extracted. The microprocessor determines whether the position of the harmonic information exceeds the set position range. If it exceeds the set position range, the laser temperature is controlled by the PID algorithm to make the position of the harmonic information conform to the set position range requirements, thereby achieving laser wavelength calibration.

[0041] Example 2

[0042] like Figure 2 As shown, the main difference between this embodiment and Embodiment 1 lies in the design of the reference air chamber 5.

[0043] Specifically, the fiber bending assembly is integrally integrated into the front end of the base, and the base is provided with a cavity that is only open at the front and rear ends. The front end of the cavity is connected to the light leakage source of the fiber bending assembly.

[0044] The focusing component 3 is installed at the front end of the cavity via a pressure ring 4 to be close to the light leakage source. The focusing component 3, together with the pressure ring 4, seals the front end of the cavity. The detector component 6 and the circuit board component 7 are encapsulated at the rear end of the cavity and seal the rear end of the cavity. After the front and rear ends of the cavity are sealed, a closed space is formed in the middle. The middle of the cavity forms the reference gas chamber. The reference gas can be directly filled into the reference gas chamber, which can save a separate reference gas chamber structure and save manufacturing costs.

[0045] Example 3

[0046] like Figure 3 As shown, the main difference between this embodiment and Embodiment 1 lies in the design of the reference air chamber 5.

[0047] To further improve the sealing performance, a cavity is provided in the base, and the focusing component 3 and the detector component 6 are sealed at both ends of the focusing component fixing member 10 to form the reference gas chamber 5.

[0048] The fiber bending assembly is integrally integrated into the front end of the base, and the light leakage source of the fiber bending assembly is directly opposite the position of the focusing assembly.

[0049] In this embodiment, the reference air chamber is assembled from a focusing component 3, a detector component 6, and a focusing component fixing component 10. The focusing component fixing component 10 can be a cylindrical structure or a similar hollow structure. The hollow part is combined with the sealing structures at both ends (focusing component 3 and detector component 6) to form an air chamber, so that the various components are integrated into a whole. During the manufacturing process, the above-mentioned integrated components can be assembled in the same process, which is beneficial for large-scale automated manufacturing. Moreover, the structure is relatively simple and the sealing performance is better.

[0050] Example 4

[0051] like Figure 4 As shown, the main difference between this embodiment and Embodiment 1 lies in the design of the optical fiber bending component 9.

[0052] The fiber bending assembly includes a concave arc surface formed on the front end of the base and a slider with an outward convex arc surface corresponding to the concave arc surface. The bending angle is adjusted by adjusting the distance between the outward convex arc surface and the concave arc surface of the slider.

[0053] When different fiber specifications require different degrees of bending to achieve the desired light leakage rate, this adjustable bending angle structure is needed to improve the applicability of the device.

[0054] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.

Claims

1. A laser wavelength calibration device based on fiber optic leakage, characterized in that: This includes fiber optic bending assemblies, focusing assemblies, reference gas cells, detector assemblies, and circuit board assemblies; The optical fiber bending assembly is provided with a mechanism for locally bending the optical fiber, so that light leaks out at the bend, forming a light leakage source. The light-concentrating component is positioned corresponding to the location of the light-leaking source and is used to concentrate the leaked light. The front end of the reference gas cell is set to correspond to the output optical path of the focusing component, so that the focused light passes through the reference gas cell; The detector assembly is located at the rear end of the reference gas cell and is used to collect light passing through the reference gas cell and convert it into an electrical signal; The circuit board assembly is connected to the detector assembly and is used to process the received electrical signals and acquire the harmonic information of the gas in the reference chamber as reference information for calibrating the laser parameters.

2. The laser wavelength calibration device based on fiber optic leakage light according to claim 1, characterized in that: It also includes a base, on which the fiber bending assembly, focusing assembly, reference gas chamber, detector assembly and circuit board assembly are all mounted.

3. The laser wavelength calibration device based on fiber optic leakage as described in claim 2, characterized in that: The fiber bending assembly, focusing assembly, reference gas chamber, detector assembly, and circuit board assembly are arranged along the same central axis based on the base.

4. The laser wavelength calibration device based on fiber optic leakage as described in claim 2 or 3, characterized in that: The fiber bending assembly is integrally integrated into the front end of the base. A cavity is provided in the base, and the front end of the cavity is connected to the light leakage source of the fiber bending assembly. The focusing assembly is installed at the front end of the cavity and close to the light leakage source through a pressure ring. The reference gas chamber is an independent gas chamber, installed in the cavity and located behind the pressure ring. The detector assembly and circuit board assembly are sealed at the rear end of the cavity.

5. The laser wavelength calibration device based on fiber optic leakage as described in claim 2 or 3, characterized in that: The fiber bending assembly is integrally integrated into the front end of the base. The base has a cavity that is open at both the front and rear ends. The front end of the cavity is connected to the light leakage source of the fiber bending assembly. The focusing assembly is installed at the front end of the cavity near the light leakage source by means of a pressure ring. The focusing assembly, together with the pressure ring, seals the front end of the cavity. The detector assembly and the circuit board assembly are encapsulated in the rear end of the cavity and seal the rear end of the cavity. The middle part of the cavity forms the reference gas chamber.

6. The laser wavelength calibration device based on fiber optic leakage light according to claim 2 or 3, characterized in that: A cavity is provided in the base, and the focusing component and the detector component are sealed and installed at both ends of the focusing component fixing component to form the reference gas chamber; the fiber bending component is integrally integrated into the front end of the base, and the light leakage source of the fiber bending component is directly facing the position of the focusing component.

7. The laser wavelength calibration device based on fiber optic leakage light according to any one of claims 1-3, characterized in that: The focusing component is a lens or a focusing mirror.

8. The laser wavelength calibration device based on fiber optic leakage light according to any one of claims 1-3, characterized in that: The fiber bending assembly includes a groove with a set curve.

9. The laser wavelength calibration device based on fiber optic leakage as described in claim 2 or 3, characterized in that: The fiber bending assembly includes a concave arc surface formed on the front end of the base and a slider with a convex arc surface corresponding to the concave arc surface. The bending angle is adjusted by adjusting the distance between the convex arc surface and the concave arc surface of the slider.

10. The laser wavelength calibration device based on fiber optic leakage light according to any one of claims 1-3, characterized in that: The circuit board assembly is a circuit board that integrates a microprocessor and peripheral circuits.

Images