A distributed fiber laser monitoring device

Abstract

The application provides a kind of distributed fiber laser monitoring device, it is related to fiber laser technical field.The distributed fiber laser monitoring device, including the circuit board front arrangement area and circuit board back arrangement area being arranged in the inside of fiber laser body, the outer surface side of the circuit board front arrangement area is fixedly installed with a plurality of first temperature measurement module, the outer surface side of the circuit board back arrangement area is fixedly installed with a plurality of second temperature measurement module, the first temperature measurement module and second temperature measurement module are all by several temperature measurement modules in series.The optical fiber transmission of sensing signal is designed, the optical fiber sensor is directly used, then the optical signal is transmitted to the central processing unit through the optical fiber, the electrical connection line is greatly reduced, the electromagnetic interference risk is reduced, the central processing unit only needs to process optical signal or a small amount of electrical signal, the standardization and modularization realize the real distributed, continuous monitoring, greatly simplify system structure, improve the maintainability of system.

Description

Technical Field

[0001] This invention relates to the field of fiber laser technology, specifically to a distributed fiber laser monitoring device. Background Technology

[0002] Information and sensing technologies, represented by fiber optic communication and fiber optic sensing, are developing rapidly. Compared with other sensors, fiber optics, as a new type of sensor, have unique advantages. They are highly waterproof, corrosion-resistant, resistant to electromagnetic interference, high-temperature resistant, and signal secure. They can be used to build sensor networks for distributed measurement, and are also inexpensive, easy to automate, and can form distributed line measurements or even field measurements. Therefore, fiber optic sensing has developed rapidly in recent years. Fiber lasers, which use rare-earth-doped glass fibers as the gain medium, have a wide range of applications, including laser fiber optic communication, laser long-distance space communication, industrial shipbuilding, automobile manufacturing, laser engraving, laser marking, laser cutting, printing roller manufacturing, metal and non-metal drilling / cutting / welding (copper brazing, quenching, cladding, and deep welding), military and defense security, medical equipment, large-scale infrastructure construction, and serving as a pump source for other lasers, among others.

[0003] High-power fiber lasers are mainstream tools for applications such as sheet metal cutting, metal welding, and additive manufacturing. However, if the high-power fiber laser source itself malfunctions, such as fiber leakage leading to increased temperature, heat accumulation due to nonlinear effects, heat generation due to melting point loss, or compression of gain and power transmission fibers, it may severely self-destruct, or even burn out the entire laser system. Therefore, monitoring the safe operating status of high-power fiber lasers is crucial for laser applications.

[0004] Currently, most safety parameters in high-power fiber lasers are related to heat / temperature. Self-safety protection in high-power fiber laser systems utilizes point-type detectors and sensors for self-checking and real-time monitoring of the operating status at various locations within the system. These point-type sensors require individual wiring for each sensor and a circuit board for each sensor path. Signal acquisition, demodulation, uploading, and processing feedback must be performed on the circuit board. This results in numerous and complex wiring lines, a significant workload, especially in confined spaces, and increases both hardware costs and space requirements.

[0005] To address this, we have developed a new type of distributed fiber laser monitoring device. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention provides a distributed fiber laser monitoring device. It solves the problem that current high-power fiber laser systems rely on point-type detectors and sensors for self-checking and real-time monitoring of the operating status at various locations within the system. These point-type sensors require each sensor to be wired, and each sensor path needs to be connected to a circuit board. Signal acquisition, demodulation, uploading, and processing feedback must be performed on the circuit board, resulting in numerous and complex lines, a large wiring workload, especially in confined spaces, and increased hardware costs and space requirements.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a distributed fiber laser monitoring device, comprising a front-side layout area and a back-side layout area of ​​a circuit board disposed inside the fiber laser body, wherein a plurality of first temperature measuring modules are fixedly installed on one side of the outer surface of the front-side layout area of ​​the circuit board, and a plurality of second temperature measuring modules are fixedly installed on one side of the outer surface of the back-side layout area of ​​the circuit board, wherein each of the first and second temperature measuring modules is composed of a plurality of temperature measuring modules connected in series.

[0008] The temperature measuring module is a coiled temperature measuring optical fiber. The temperature measuring modules of each temperature measuring module are continuously arranged in the same area to be monitored, and one end of the temperature measuring optical fiber of each temperature measuring module is electrically connected to an optical fiber temperature sensor.

[0009] The fiber optic temperature sensor is electrically connected to a controller, and the controller is electrically connected to a signal generator.

[0010] The other end of the temperature measuring fiber of each temperature measuring module is electrically connected to a preamplifier, the preamplifier is electrically connected to a lock-in amplifier, and the lock-in amplifier is electrically connected to the output of the signal generator.

[0011] The lock-in amplifier is also electrically connected to a data acquisition unit, which is electrically connected to a control terminal.

[0012] Preferably, the temperature-measuring optical fiber, which is connected in series and coiled on the surface of the circuit board, serves as a distributed temperature sensor. A signal generator emits a modulated optical signal into the optical fiber, collects the temperature-modulated optical signal scattered back along the optical fiber, and these signals are pre-amplified and lock-in amplified to extract effective information. The data is then digitized by the data acquisition unit and sent to the control terminal for analysis and display, thereby realizing real-time, distributed monitoring of the temperature distribution in different areas of the circuit board inside the fiber laser.

[0013] This invention provides a distributed fiber laser monitoring device. It has the following advantages: 1. This distributed fiber laser monitoring device, by designing fiber optic transmission of sensing signals, directly uses fiber optic sensors (fiber optic temperature sensors), and then transmits the optical signals to the central processing unit through optical fibers, greatly reducing electrical connection lines. The central processing unit only needs to process optical signals or a small amount of electrical signals, reducing the risk of electromagnetic interference.

[0014] 2. This distributed fiber laser monitoring device, through its design, adopts fully distributed fiber optic sensing technology to replace some point sensors, completely replacing point sensors and their wiring. Standardization and modularization achieve true distributed and continuous monitoring, greatly simplifying the system structure, reducing wiring costs and maintenance difficulty, reducing the burden on the central processing unit, simplifying wiring, and improving the modularity and maintainability of the system.

[0015] 3. This distributed fiber laser monitoring device detects abnormal temperatures via fiber optic temperature sensors. Once an abnormal temperature rise is detected, it can report the location of the abnormality to the control terminal, facilitating staff to inspect the corresponding location. This allows for timely detection of faults in the fiber laser itself, monitoring the safe operating status of high-power fiber lasers, and providing accurate temperature information for fire prevention, which is crucial for laser applications. Attached Figure Description

[0016] Figure 1 This is a perspective view of the fiber laser body of the present invention; Figure 2 This is a schematic diagram of the installation of the circuit board front layout area of ​​the present invention; Figure 3 This is a schematic diagram of the mounting area on the back of the circuit board of the present invention; Figure 4 This is a schematic diagram of the structure of a single first temperature measuring module of the present invention; Figure 5 This is a schematic diagram illustrating the working principle of the present invention.

[0017] The components include: 1. Fiber laser body; 2. Front layout area of ​​circuit board; 3. First temperature measurement module; 4. Back layout area of ​​circuit board; 5. Second temperature measurement module; 6. Temperature measurement module. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Examples, such as Figures 1-5As shown, this embodiment of the invention provides a distributed fiber laser monitoring device, including a circuit board front arrangement area 2 and a circuit board back arrangement area 4 disposed inside the fiber laser body 1. A plurality of first temperature measuring modules 3 are fixedly installed on one side of the outer surface of the circuit board front arrangement area 2, and a plurality of second temperature measuring modules 5 are fixedly installed on one side of the outer surface of the circuit board back arrangement area 4. Both the first temperature measuring modules 3 and the second temperature measuring modules 5 are composed of a plurality of temperature measuring modules 6 connected in series.

[0020] Temperature measurement module 6 is a coiled temperature measurement optical fiber. The temperature measurement modules 6 of each temperature measurement module are continuously arranged in the same area to be monitored. This means that the optical fiber is coiled along the surface of the circuit board, covering the area to be monitored, and can sense the temperature at different points in the area. Moreover, one end of the temperature measurement optical fiber of each temperature measurement module is electrically connected to an optical fiber temperature sensor.

[0021] The fiber optic temperature sensor is electrically connected to a controller, which in turn is electrically connected to a signal generator. The signal generator produces a signal of a specific frequency, which is input to the fiber optic temperature sensor. Based on this signal, the fiber optic temperature sensor (typically a laser or light source) transmits an optical signal (e.g., pulsed light) to the temperature-sensing fibers of each temperature-sensing module (3 and 5).

[0022] The emitted optical signal propagates along the temperature-sensing optical fiber. During propagation, especially at scattering points on the fiber (such as Rayleigh scattering), the optical signal interacts with the surrounding environment (i.e., the circuit board and its components). The optical fiber itself is temperature-sensitive; its optical properties (such as backscattered light intensity and phase) change with temperature, affecting the characteristics of the scattered light (e.g., the intensity or phase of backscattered light varies with temperature and location). Therefore, the returned optical signal carries information about the temperature at various points along the fiber, and due to the continuity of the fiber and the timing of scattering (optical pulse propagation time), this information also includes spatial location information.

[0023] The other end of the temperature measuring fiber of each temperature measuring module is electrically connected to a preamplifier, the preamplifier is electrically connected to a lock-in amplifier, and the lock-in amplifier is electrically connected to the output of the signal generator.

[0024] The other end of the temperature-sensing optical fiber of each temperature-sensing module (3 and 5) is connected to a preamplifier. This allows the weak light signal carrying temperature information returning from the optical fiber to be collected first, and then converted by photoelectric conversion (if there is no photodiode before the preamplifier) ​​and pre-amplified for subsequent processing. Furthermore, the amplified signal is input to a lock-in amplifier, which uses the same reference signal from the signal generator (i.e., the signal initially used to modulate the light source) to accurately extract the weak signal components that are in phase and frequency with the reference signal, while greatly suppressing noise and other interference signals.

[0025] Since the returned optical signal is modulated by the initial signal, the lock-in amplifier is able to effectively "lock in" from the noisy background and extract useful, temperature-related signal changes.

[0026] The lock-in amplifier is also electrically connected to a data acquisition unit, which is electrically connected to a control terminal. The demodulated and amplified signal output by the lock-in amplifier reflects the temperature information at various points along the optical fiber. This signal is sent to the data acquisition unit. The data acquisition unit is responsible for converting the analog signal into a digital signal and performing necessary digital processing (such as filtering and calibration). The digitized temperature data is then transmitted to the control terminal.

[0027] The control terminal receives data from the data acquisition unit and performs further processing, analysis, and visualization (e.g., generating temperature distribution maps). Operators can also monitor the temperature of critical areas inside the laser through the control terminal. If the temperature exceeds a preset threshold, the system can issue an alarm or even trigger control logic to adjust the laser's operating parameters or take other protective measures.

[0028] In summary, the working principle of this device is as follows: the temperature-measuring optical fibers, which are connected in series and coiled on the surface of the circuit board, act as distributed temperature sensors. A signal generator emits modulated light signals into the optical fibers, and collects the temperature-modulated light signals scattered back along the optical fibers. These signals are then pre-amplified and lock-in amplified to extract effective information. After being digitized by the data acquisition unit, they are sent to the control terminal for analysis and display, thereby realizing real-time, distributed monitoring of the temperature distribution in different areas of the circuit board inside the fiber laser.

[0029] Compared to traditional point-type temperature sensors, this distributed sensing technology based on fiber optics has advantages such as continuous operation, distributed sensing, resistance to electromagnetic interference, and high temperature resistance, making it very suitable for monitoring the internal temperature of complex fiber lasers that are sensitive to electromagnetic environments.

[0030] Working principle: The core purpose of this device is to monitor the temperature distribution in different areas (front and back) of the circuit board inside the fiber laser body, so as to determine its operating status and whether there is a risk of overheating. For example, distributed fiber temperature sensors can be used to monitor the continuous distribution of fiber laser core or cladding temperature, replacing multiple point temperature probes. Specifically, addressing the wiring, cost, and complexity issues associated with point sensors in the internal condition monitoring of high-power fiber lasers, this device employs "electrification" and "fiber optic integration." By converting sensor signals into optical signals for transmission, replacing some point sensors with distributed fiber optic sensing technology, and developing integrated fiber optic sensor nodes, the system structure is significantly simplified, costs are reduced, and reliability and security are improved. Among them, by designing fiber optic transmission of sensing signals, fiber optic sensors (fiber optic temperature sensors) are directly used, and then the optical signals are transmitted to the central processing unit through optical fibers, which greatly reduces electrical connection lines, simplifies wiring, and reduces the risk of electromagnetic interference. The central processing unit only needs to process optical signals or a small amount of electrical signals. By designing and adopting fully distributed fiber optic sensing technology to replace some point sensors, completely replacing point sensors and their wiring, standardization and modularization have enabled true distributed and continuous monitoring, greatly simplifying the system structure, reducing wiring costs and maintenance difficulty, reducing the burden on the central processing unit, simplifying wiring, and improving the modularity and maintainability of the system.

[0031] Once an abnormal temperature rise is detected by the temperature-measuring fiber optic cable, the abnormal location can be reported to the control terminal, facilitating staff to inspect the corresponding location. This enables timely detection of faults in the fiber laser itself, monitoring the safe operation status of high-power fiber lasers, and providing accurate temperature information for fire prevention, which is crucial for laser applications.

[0032] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A distributed fiber laser monitoring device, characterized in that, The circuit includes a front-side layout area (2) and a back-side layout area (4) of the circuit board located inside the fiber laser body (1). Multiple first temperature measuring modules (3) are fixedly installed on one side of the outer surface of the front-side layout area (2), and multiple second temperature measuring modules (5) are fixedly installed on one side of the outer surface of the back-side layout area (4). Both the first temperature measuring module (3) and the second temperature measuring module (5) are composed of several temperature measuring modules (6) connected in series.

2. The distributed fiber laser monitoring device according to claim 1, characterized in that: The temperature measuring module (6) is a coiled temperature measuring optical fiber. The temperature measuring modules (6) of each temperature measuring module are continuously arranged in the same area to be monitored, and one end of the temperature measuring optical fiber of each temperature measuring module is electrically connected to an optical fiber temperature sensor.

3. The distributed fiber laser monitoring device according to claim 1, characterized in that: The fiber optic temperature sensor is electrically connected to a controller, and the controller is electrically connected to a signal generator.

4. The distributed fiber laser monitoring device according to claim 1, characterized in that: The other end of the temperature measuring fiber of each temperature measuring module is electrically connected to a preamplifier, the preamplifier is electrically connected to a lock-in amplifier, and the lock-in amplifier is electrically connected to the output of the signal generator.

5. A distributed fiber laser monitoring device according to claim 4, characterized in that: The lock-in amplifier is also electrically connected to a data acquisition unit, which is electrically connected to a control terminal.

6. The distributed fiber laser monitoring device according to claim 1, characterized in that: The temperature-sensing optical fibers, which are connected in series and coiled on the surface of the circuit board, serve as distributed temperature sensors. A signal generator emits modulated light signals into the optical fibers and collects the temperature-modulated light signals scattered back along the optical fibers. These signals are then pre-amplified and lock-in amplified to extract valid information. After being digitized by a data acquisition unit, they are sent to the control terminal for analysis and display, thereby realizing real-time, distributed monitoring of the temperature distribution in different areas of the circuit board inside the fiber laser.

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