Optical fiber temperature sensor based on principle of mapping from parameter to space

Abstract

The invention provides an optical fiber temperature sensor based on the principle of mapping from parameters to space. The sensor is composed of a laser light source (A), a sensing module (B) and a receiving identification module (C). The sensing module (B) comprises an input optical fiber (B1) and a sensing probe (B2). And the receiving identification module (C) comprises a receiving optical fiber (C1), a camera (C2), a calculation unit (C3) and a display unit (C4). The sensing module (B) realizes a mapping relation between temperature change and spatial distribution change of an input light field, and the receiving identification module (C) realizes acquisition and post-processing of spatial distribution of the light field. The optical fiber temperature sensor is based on the principle of mapping from parameters to space, necessary spectral analysis equipment in traditional optical fiber sensing is avoided, the optical fiber temperature sensing cost can be remarkably reduced, and the optical fiber temperature sensor has wide application value in temperature monitoring in the fields of biomedicine, chemical engineering, environment monitoring and the like.

Description

Technical Field

[0001] The present invention relates to an optical fiber temperature sensor based on the principle of mapping from parameters to space, belonging to the field of optical fiber sensing technology. Background Art

[0002] As a new type of sensor based on optical principles, optical fiber sensors have developed almost synchronously with optical fiber communication technology and have become one of the forefront research directions in sensing technology due to their excellent performance. Compared with traditional electronic sensors, optical fiber sensors exhibit many advantages, including extremely high sensitivity, excellent electromagnetic interference resistance, compact structure design, lightweight characteristics, and flexible networking capabilities. More importantly, optical fibers themselves have inherent properties such as electrical insulation, high temperature resistance, and chemical stability, which enable optical fiber sensors to not only perform well in conventional environments but also maintain stable performance and reliability in extreme working conditions such as flammable, explosive, high-radiation, and strong electromagnetic interference environments. These remarkable characteristics have promoted their wide application in high-tech fields such as industrial monitoring, aerospace, medical diagnosis, energy development, and intelligent manufacturing.

[0003] In the field of temperature sensing, traditional optical fiber temperature sensors are mainly based on the principle of light interference, including Mach-Zehnder interference, multimode interference, and F-P interference. They map the change of external temperature parameters by collecting the change of interference conditions, such as the drift of interference wavelength or the change of interference intensity. Therefore, traditional optical fiber temperature sensors must use expensive broadband light sources and spectrometers to complete the sensing of external temperature. The high equipment cost has hindered the entry of optical fiber sensors into application scenarios.

[0004] Therefore, designing an optical fiber temperature sensor that does not rely on expensive spectrometers is of great significance for reducing system costs and broadening its coverage in various application scenarios. This research direction not only meets the urgent needs of the current industrial and scientific fields for economical and high-performance sensors but also provides a new technical path for the future development of optical fiber sensors.

[0005] Aiming at the problems existing in the above-mentioned prior art, the present invention innovatively proposes an optical fiber temperature sensor based on the principle of mapping from parameters to space. Compared with traditional optical fiber sensors, the present invention uses a camera to collect the optical field emitted from the optical fiber and uses the spatial distribution of the emitted light to map the external temperature conditions. When the external temperature changes, the spatial distribution of the emitted light changes accordingly. By using a neural network to demodulate the mapping between the optical space distribution and the external temperature, the purpose of temperature sensing is achieved. The present invention avoids the indispensable spectral analysis equipment in traditional optical fiber sensing, can significantly reduce the cost of optical fiber temperature sensing, and has broad application prospects and popularization value in temperature monitoring in fields such as biomedicine, chemical engineering, and environmental monitoring. Summary of the Invention

[0006] The object of the present invention is to provide an optical fiber temperature sensor based on the principle of mapping from parameters to space.

[0007] The object of the present invention is achieved as follows:

[0008] The optical fiber temperature sensor based on the principle of mapping from parameters to space is composed of a laser light source (A), a sensing module (B), and a receiving and identifying module (C). The sensing module (B) includes an input optical fiber (B1) and a sensing probe (B2). The receiving and identifying module (C) includes a receiving optical fiber (C1), a camera (C2), a computing unit (C3), and a display unit (C4). The sensing probe (B2) includes a microstructure unit made of a temperature-sensitive material, which can form a mapping relationship between temperature changes and changes in the spatial distribution of the input optical field. The specific principle is as follows: The microstructure unit made of the temperature-sensitive material can cause the laser input by the input optical fiber (B1) to generate a light field spatial distribution with a specific shape; when the temperature changes, the optical properties of the temperature-sensitive material change, resulting in changes in the optical properties or structure of the microstructure unit, thereby causing changes in the spatial distribution of the input laser light field, and thus realizing the mapping relationship from temperature changes to changes in the spatial distribution of the input optical field. The working process of the optical fiber temperature sensor based on the principle of mapping from parameters to space is as follows: The laser emitted by the laser light source (A) is transmitted to the sensing probe (B2) via the input optical fiber (B1), and the mapping from temperature changes to changes in the spatial distribution of the input optical field is completed at the sensing probe (B2). Subsequently, it is received by the receiving optical fiber (C1) and the spatial distribution of the light field at the output end of the sensing probe (B2) is collected by the camera (C2). The collected light field spatial distribution map is demodulated to obtain the temperature value through an intelligent recognition model pre-trained in the computing unit (C3), and the finally demodulated temperature value is displayed and output through the display unit.

[0009] The sensing probe (B2) is a microstructure unit made of a temperature-sensitive material, which can generate a light field spatial distribution with a certain pattern or random speckles according to temperature changes. Its function is to be able to generate different light field spatial distributions according to temperature changes and realize the mapping relationship from temperature changes to changes in the spatial distribution of the input optical field.

[0010] The temperature-sensitive material of the microstructure unit constituting the sensing probe (B2) can be polydimethylsiloxane (PDMS), or other temperature-sensitive materials.

[0011] The input optical fiber (B1) in the sensing module (B) and the receiving optical fiber (C1) in the receiving and identifying module (C) are fixedly connected through a packaging structure (D1-1). Its function is to stably transmit the input light field spatial distribution to the receiving optical fiber (C1) for collection by the camera (C2).

[0012] The receiving optical fiber (C1) described above can be an optical fiber bundle (C1-1) or a multi-core optical fiber (C1-2). Its function is to receive the optical field spatial distribution output from the output end of the sensing probe (B2) and transmit it to the camera (C2) for the camera (C2) to collect.

[0013] The computing unit (C3) described above is an embedded computing platform with high-performance data processing and computing capabilities. It can be a board supporting edge computing or other computing systems integrated with data analysis and algorithm deployment capabilities. In addition, an intelligent image recognition model for temperature demodulation is pre-trained in the computing unit (C3). The intelligent image recognition model can demodulate the temperature value from the optical field spatial distribution map collected by the camera (C2).

[0014] Compared with the prior art, the present invention has the following remarkable advantages:

[0015] The present invention proposes a new measurement path based on the mapping of parameters and optical field spatial distribution in the field of optical fiber sensing, breaking through the limitations of traditional reliance on spectral analysis. By introducing artificial intelligence and advanced computing algorithms, the present invention realizes the deep integration of optical fiber sensing technology and intelligent data processing. Using an efficient image recognition algorithm to replace traditional spectral demodulation equipment, it overcomes the bottlenecks of high cost and bulky equipment of spectrometers in the prior art, provides a more economical temperature measurement solution, and has important application prospects and promotion value. Description of the Drawings

[0016] In order to more clearly illustrate the technical solutions of the present invention, the drawings required for the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0017] Figure 1 It is a schematic diagram of the device of an optical fiber temperature sensor based on the principle of mapping from parameters to space. It is composed of a laser light source (A), a sensing module (B), and a receiving and identifying module (C).

[0018] Figure 2 It is a schematic diagram of the connection structure between the sensing probe and the receiving optical fiber in Embodiment 1.

[0019] Figure 3 It is a schematic diagram of the connection structure between the sensing probe and the receiving optical fiber in Embodiment 2.

[0020] Figure 4 It is a schematic diagram of the connection structure between the sensing probe and the receiving optical fiber in Embodiment 3.

[0021] Figure 5It is a schematic structural diagram of the connection between the sensing probe and the receiving optical fiber in Embodiment 4.

[0022] Figure 6 It is a schematic cross-sectional view of the fiber bundle (C1-1) in the receiving and identifying module (C).

[0023] Figure 7 It is a schematic cross-sectional view of the multi-core optical fiber (C1-2) in the receiving and identifying module (C). Detailed implementation manners

[0024] Next, the technical solutions in the embodiments of the present invention will be further described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other examples obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0025] An optical fiber temperature sensor based on the principle of mapping from parameters to space proposed by the present invention has a device schematic diagram as Figure 1 shown. It consists of a laser light source (A), a sensing module (B), and a receiving and identifying module (C). The sensing module (B) includes an input optical fiber (B1) and a sensing probe (B2). The receiving and identifying module (C) includes a receiving optical fiber (C1), a camera (C2), a calculation unit (C3), and a display unit (C4). The sensing probe (B2) includes a microstructure unit made of a temperature-sensitive material, which can form a mapping relationship between temperature changes and changes in the spatial distribution of the input light field. The specific principle is as follows: The microstructure unit made of the temperature-sensitive material can cause the laser input by the input optical fiber (B1) to generate a light field spatial distribution of a specific shape; when the temperature changes, the optical properties of the temperature-sensitive material change, resulting in changes in the optical properties or structure of the microstructure unit, thereby causing changes in the light field spatial distribution of the input laser, and thus realizing the mapping relationship from temperature changes to changes in the light field spatial distribution.

[0026] Embodiment 1: An optical fiber temperature sensor using a sensing probe with a "PDMS-air bubble" structure and a receiving optical fiber with a "fiber bundle" structure.

[0027] As Figure 2 shown, in this Embodiment 1, the sensing probe (B2) is composed of PDMS (B2-1) and air bubbles (B2-2), and is butt-welded to the input optical fiber (B1) without misalignment; the receiving optical fiber (C1) is composed of a fiber bundle (C1-1), and the cross-sectional view of the fiber bundle is as Figure 6 shown, and is fixedly connected to the input optical fiber (B1) through a packaging structure (D1-1).

[0028] The working mechanism of Embodiment 1 is as follows: The laser emitted by the laser light source (A) is transmitted to the sensing probe (B2) via the input optical fiber (B1); in the sensing probe (B2), the PDMS (B2-1) is divided into two regions by air bubbles (B2-2), which is equivalent to two lenses. When the temperature rises (or falls), the volumes of the two PDMS regions become larger (or smaller), affecting the effect of the overall structure of the sensing probe (B2) on the divergence or convergence of light, generating a spatially distributed output light field with regular changes, and completing the mapping from temperature change to spatially distributed light field change; subsequently, the receiving optical fiber (C1) uses the optical fiber bundle (C1-1) for reception and transmission, and the spatially distributed light field at the output end of the sensing probe (B2) is collected by the camera (C2). The collected spatially distributed light field image is demodulated to obtain the temperature value through the intelligent recognition model pre-trained in the calculation unit (C3), and the finally demodulated temperature value is displayed and output through the display unit.

[0029] Embodiment 2: An optical fiber temperature sensor using a sensing probe with a nanoparticle-doped structure and a receiving optical fiber with an "optical fiber bundle" structure.

[0030] As Figure 3 shown, in Embodiment 2, the sensing probe (B2) is composed of a temperature-sensitive material (B2-4) embedded with nanoparticles (or air bubbles) (B2-3) and is fusion-spliced with the input optical fiber (B1) without misalignment; the receiving optical fiber (C1) is composed of an optical fiber bundle (C1-1) and is fixedly connected to the input optical fiber (B1) through a packaging structure (D1-1).

[0031] The working mechanism of Embodiment 2 is as follows: The laser emitted by the laser light source (A) is transmitted to the sensing probe (B2) via the input optical fiber (B1); in the sensing probe (B2), the nanoparticles (or air bubbles) (B2-3) are randomly distributed in the temperature-sensitive material, scattering the input light, thereby forming a speckle pattern at the output end of the sensing probe (B2). When the temperature changes, the temperature-sensitive material undergoes a volume change, driving the change in the distribution position of the internal particles, causing the speckle pattern to change, and completing the mapping from temperature change to spatially distributed light field change; subsequently, the receiving optical fiber (C1) uses the optical fiber bundle (C1-1) for reception and transmission, and the spatially distributed light field at the output end of the sensing probe (B2) is collected by the camera (C2). The collected spatially distributed light field image is demodulated to obtain the temperature value through the intelligent recognition model pre-trained in the calculation unit (C3), and the finally demodulated temperature value is displayed and output through the display unit.

[0032] Embodiment 3: An optical fiber temperature sensor using a sensing probe with a nanoparticle-doped structure and a receiving optical fiber with a "multi-core optical fiber" structure

[0033] Compared with Embodiment 2, the difference in this Embodiment 3 is that a multi-core optical fiber (C1-2) is used as the receiving optical fiber (C1) and is directly fusion spliced with the sensing probe (B2), as Figure 4 shown. Its working mechanism is the same as that of Embodiment 2.

[0034] Embodiment 4: An optical fiber temperature sensor using a sensing probe with a "PDMS-air bubble" structure and a receiving optical fiber with a "multi-core optical fiber" structure

[0035] Compared with Embodiment 1, the difference in this Embodiment 4 is that a multi-core optical fiber (C1-2) is used as the receiving optical fiber (C1) and is directly fusion spliced with the sensing probe (B2), as Figure 5 shown. Its working mechanism is the same as that of Embodiment 1.

[0036] And the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

[0037] What is disclosed above is only a preferred embodiment of the present invention. Of course, the scope of the rights of the present invention cannot be limited thereby. Those of ordinary skill in the art can understand all or part of the processes of implementing the above embodiments, and the equivalent changes made according to the claims of the present invention still fall within the scope covered by the invention.

Claims

1. An optical fiber temperature sensor based on the principle of mapping from parameter to space. It is characterized by: It consists of a laser light source (A), a sensor module (B) and a receiving and identifying module (C). The sensor module (B) includes an input optical fiber (B1) and a sensor probe (B2). The receiving and identifying module (C) includes a receiving optical fiber (C1), a camera (C2), a computing unit (C3) and a display unit (C4). The sensor probe (B2) includes a microstructure unit composed of a temperature-sensitive material, which can form a mapping relationship between temperature changes and changes in the spatial distribution of the input light field. The specific principle is as follows: the microstructure unit composed of the temperature-sensitive material can make the laser input by the input optical fiber (B1) produce a light field spatial distribution of a specific shape; when the temperature changes, the optical properties of the temperature-sensitive material change, resulting in changes in the optical properties or structure of the microstructure unit, thereby causing the light field spatial distribution of the input laser to change, thereby realizing a mapping relationship from temperature changes to changes in the spatial distribution of the input light field. The working process of the optical fiber temperature sensor based on the principle of mapping from parameter to space is as follows: the laser light emitted by the laser light source (A) is transmitted to the sensing probe (B2) via the input optical fiber (B1), and the mapping of the temperature change to the input light field spatial distribution change is completed in the sensing probe (B2), and then the light field spatial distribution at the output end of the sensing probe (B2) is received by the receiving optical fiber (C1) and collected by the camera (C2), and the collected light field spatial distribution map is demodulated into a temperature value through an intelligent recognition model pre-trained in the computing unit (C3), and finally the demodulated temperature value is displayed and output through a display unit.

2. The optical fiber temperature sensor based on the parameter-to-space mapping principle according to claim 1, characterized in that: The temperature sensitive material of the microstructure unit constituting the sensing probe (B2) may be polydimethylsiloxane (PDMS) or other temperature sensitive materials.

3. The optical fiber temperature sensor based on the parameter-to-space mapping principle according to claim 1, characterized in that: The receiving optical fiber (C1) can be an optical fiber bundle or a multi-core optical fiber, and its function is to receive the spatial distribution of the light field output by the output end of the sensing probe (B2) and transmit it to the camera (C2) for collection by the camera (C2).

4. The optical fiber temperature sensor based on the parameter-to-space mapping principle according to claim 1, characterized in that: The computing unit (C3) is an embedded computing platform with high-performance data processing and computing capabilities, which can be a board supporting edge computing, or other computing systems that integrate data analysis and algorithm deployment capabilities. In addition, an intelligent image recognition model for temperature demodulation is pre-trained in the computing unit (C3), and the intelligent image recognition model can demodulate the temperature value from the light field spatial distribution map collected by the camera (C2).

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