CN110702263B - A temperature measurement device and method for large core diameter multimode optical fiber - Google Patents

Abstract

The embodiment of the present invention discloses a temperature measurement device and method for a large core multimode optical fiber, characterized in that the device comprises: a frequency sweeping light source, used to provide the device with a linear frequency sweeping light with a central wavelength of 1550nm; a first fiber coupler, used to divide the linear frequency sweeping light into a first frequency sweeping light signal and a second frequency sweeping light signal; an auxiliary interference module, receiving the first frequency sweeping light signal to generate a clock signal; a main interference module, receiving the second frequency sweeping light signal to generate a beat frequency interference signal; a data acquisition module, receiving the clock signal and the beat frequency interference signal, and outputting them to a data processing module; a data processing module, based on the signal received by the data acquisition module, generates the temperature data of the large core multimode optical fiber. Thus, the temperature measurement of the large core multimode optical fiber can be realized simply and quickly, which greatly improves the measurement efficiency and reduces the measurement cost.

Description

A temperature measurement device and method for large core diameter multimode optical fiber

Technical field

Embodiments of the present invention relate to the field of optical fiber sensing, and in particular to a temperature measurement method and device for a large core diameter multimode optical fiber that measures the temperature of a large core diameter special multimode energy optical fiber.

Background technique

With the continuous advancement of energy optoelectronics technology, various new high-power lasers and laser processing equipment continue to emerge. Laser equipment uses optical fiber to output laser, which has replaced the traditional output method. In particular, the demand for energy transmission optical fiber and its kits is also increasing. The bigger. The excellent characteristics of energy optical fiber make it widely used in the field of high-power optical energy transmission, such as laser transmission, laser coupling, laser welding, laser cutting, laser medical field, etc.

In the field of laser transmission, large core diameter special multi-mode energy transmission optical fiber can not only be used as the output fiber of the laser, but also can transmit energy over long distances. While transmitting high-power energy signals, it must be considered whether the high-power energy signals will cause The internal temperature of the optical fiber increases, which affects the structural characteristics of the optical fiber. For example, the optical fiber coating may absorb the transmitted energy, or the high-power signal transmitted may cause the local temperature at the bend of the optical fiber to be too high, causing structural failure of the optical fiber. Therefore, it is particularly important to detect the temperature of large-core energy-transmitting optical fibers. By detecting temperature indicators that reflect the health status of the structure, early warning of structural damage can be achieved.

However, in the process of realizing the present invention, the inventor discovered that some existing optical fiber temperature measurement technologies are based on single-mode optical fibers. For large-core diameter multi-mode optical fibers, how to efficiently perform temperature measurement is an urgent problem to be solved. question.

Contents of the invention

In view of this, embodiments of the present invention provide a temperature measurement method and device for a large core diameter multimode optical fiber, which solves the temperature measurement problem of a multimode energy optical fiber with large core diameter characteristics.

In a first aspect, embodiments of the present invention provide a temperature measurement device for large core diameter multimode optical fiber, which includes:

A swept frequency light source can be used to provide the device with linear frequency swept light with a central wavelength of 1550nm;

A first optical fiber coupler can be used to divide the linear frequency sweep light into a first frequency sweep optical signal and a second frequency sweep optical signal;

an auxiliary interference module, which can receive the first frequency-sweeping optical signal to generate a clock signal;

The main interference module can receive the second frequency sweep optical signal to generate a beat frequency interference signal;

The data acquisition module can receive the clock signal and the beat frequency interference signal and output them to the data processing module;

The data processing module can generate temperature data of the large core diameter multimode optical fiber based on the signal received by the data acquisition module.

Optionally, the main interferometer may include:

A second optical fiber coupler, a polarization controller, a large core multimode circulator, an optical fiber to be tested, a mode matcher, a third optical fiber coupler, a polarization beam splitter, and a photodetector; wherein:

The second optical fiber coupler divides the second frequency-sweeping optical signal into two paths. One path obtains the reference arm signal through the polarization controller and enters the third optical fiber coupler; the other path passes through the large core diameter multi-mode The first port of the circulator, the optical fiber to be tested, the second port of the large core diameter multimode circulator, the third port of the large core diameter multimode circulator, and the mode matcher obtain the signal arm signal , enter the third optical fiber coupler;

The third optical fiber coupler mixes the reference arm signal and the signal arm signal, and outputs the mixed signals to the polarization beam splitter to obtain a first optical signal and a second optical signal orthogonal to each other, and outputs the first optical signal and the second optical signal to the photodetector;

The photoelectric detector converts the first optical signal and the second optical signal into electrical signals, and outputs the electrical signals to the data acquisition module.

Optionally, the pattern matcher may include:

A first-stage pattern matcher and a second-stage pattern matcher are connected in series; wherein:

The input end of the first-stage mode matcher is connected to a 105μm/125μm special multimode optical fiber, and the output end is connected to a 62.5μm/125μm multimode optical fiber;

The input end of the second-stage mode matcher is connected to the 62.5 μm/125 μm multi-mode optical fiber, and the output end is connected to the 10 μm/125 μm single-mode optical fiber.

Optionally, the optical fiber to be tested may include a large-core multimode power transmission optical fiber.

Optionally, the auxiliary interference module may include a Mach-Zehnder interferometer.

Through the temperature measurement device of the large core diameter multi-mode optical fiber proposed by the present invention and using OFDR technology, the temperature of the large core diameter special multi-mode energy transmission optical fiber can be effectively measured, which greatly reduces the measurement cost while expanding the application of OFDR technology. .

In a second aspect, embodiments of the present invention also provide a temperature measurement method for large core diameter multimode optical fiber. The method may include:

A swept frequency light source is used to provide the device with linear frequency swept light with a central wavelength of 1550nm;

Using a first optical fiber coupler to split the linear frequency-sweep light into a first frequency-sweep light signal and a second frequency-sweep light signal;

Using an auxiliary interference module to receive the first frequency sweep optical signal to generate a clock signal;

Utilize the main interference module to receive the second frequency sweep optical signal to generate a beat frequency interference signal;

A data acquisition module is used to receive the clock signal and the beat frequency interference signal to generate temperature data of the large core diameter multimode optical fiber.

Optionally, the main interferometer may include:

The second fiber coupler, polarization controller, large core diameter multi-mode circulator, fiber to be tested, mode matcher, third fiber coupler, polarization beam splitter, photodetector; among which:

The second optical fiber coupler divides the second frequency-sweeping optical signal into two paths. One path obtains the reference arm signal through the polarization controller and enters the third optical fiber coupler; the other path passes through the large core diameter multi-mode The first port of the circulator, the optical fiber to be tested, the second port of the large core diameter multimode circulator, the third port of the large core diameter multimode circulator, and the mode matcher obtain the signal arm signal , enter the third optical fiber coupler;

The third optical fiber coupler mixes the reference arm signal and the signal arm signal, and outputs them to the polarization beam splitter to obtain a first optical signal and a second optical signal that are orthogonal to each other, and The first optical signal and the second optical signal are output to the photodetector;

The photodetector converts the first optical signal and the second optical signal into electrical signals and outputs them to the data acquisition module.

Optionally, the pattern matcher may include:

A first-stage pattern matcher and a second-stage pattern matcher are connected in series; wherein:

The input end of the first-stage mode matcher is connected to a 105μm/125μm special multimode optical fiber, and the output end is connected to a 62.5μm/125μm multimode optical fiber;

The input end of the second-stage mode matcher is connected to the 62.5 μm/125 μm multi-mode optical fiber, and the output end is connected to the 10 μm/125 μm single-mode optical fiber.

Optionally, the optical fiber to be tested may include a large-core multimode power transmission optical fiber.

Optionally, the auxiliary interference module may include a Mach-Zehnder interferometer.

Through the temperature measurement method of large core diameter multi-mode optical fiber proposed by the present invention and using OFDR technology, the temperature of large core diameter special multi-mode energy transmission optical fiber can be effectively measured, which greatly reduces the measurement cost while expanding the application of OFDR technology. . At the same time, it solves the problem of excessive insertion loss when transmitting optical signals from large core diameter multimode fiber to small core diameter single mode fiber when using large core diameter multimode fiber for temperature sensing.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

Figure 1 is a schematic structural diagram of a temperature measurement device for large core diameter multi-mode optical fiber according to an embodiment of the present invention;

Figure 2 is a schematic structural diagram of a temperature measurement device for a large core diameter multi-mode optical fiber provided by another embodiment of the present invention;

FIG. 3 is a schematic structural diagram of a preferred multimode device part of a large core diameter multimode optical fiber temperature measurement device provided by an embodiment of the present invention.

Reference signs:

1-Scanning light source; 2-Auxiliary interference module; 3-Main interference module; 4-DAQ data acquisition module; 5-Data processing module; 6-Mach-Zehnder interferometer; 7-First fiber coupler; 8-No. Two fiber couplers; 9-polarization controller; 10-third fiber coupler; 11-clock signal; 12-mode matcher; 13-large core diameter multi-mode circulator; 14-fiber to be tested: large core diameter multi-mode Mode energy transfer fiber; 15-polarizing beam splitter; 16-photodetector;

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and examples. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for convenience of description, only some but not all structures related to the present invention are shown in the drawings.

In addition, it should be noted that, for convenience of description, only part but not all of the content related to the present invention is shown in the drawings. Before discussing example embodiments in more detail, it should be mentioned that some example embodiments are described as processes or methods depicted as flowcharts. Although the flowcharts describe various operations (or steps) as a sequential process, many of the operations may be performed in parallel, concurrently, or simultaneously. Additionally, the order of operations can be rearranged. The process may be terminated when its operations are completed, but may also have additional steps not included in the figures. A process may correspond to a method, function, procedure, subroutine, subroutine, etc.

Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present invention. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

The present invention aims to build a set of temperature measurement devices based on large core diameter special multimode energy transmission optical fiber. It is characterized by changing the key components in the single mode OFDR system to solve the problem of large core diameter multimode optical fiber for temperature sensing. The problem of excessive insertion loss when transmitting optical signals from core diameter multimode fiber to small core diameter single mode fiber has expanded the application scenarios of OFDR systems.

FIG1 shows a schematic diagram of the structure of a temperature measurement device for a large core diameter multimode optical fiber. As shown in FIG1 , the entire system consists of four parts: a frequency sweeping light source, an auxiliary interference module, a main interference module, and a data acquisition module. Both the auxiliary interferometer and the main interferometer can be Mach-Zehnder interferometers. The frequency sweeping light source provides the system with a linear frequency sweeping light with a central wavelength of 1550 nm. The frequency sweeping light is divided into two paths. One path enters the auxiliary interferometer to generate an external clock signal used by the data acquisition module, and the other path enters the main interferometer to generate a beat frequency interference signal to be collected by the data acquisition module. Finally, the signal is input into a data processing module (e.g., a PC) to obtain temperature data after calculation and processing.

Figure 2 shows a more specific structural diagram of the temperature measurement device of the large core diameter multi-mode optical fiber. The temperature measurement device includes:

A swept frequency light source, used to provide the device with linear swept frequency light with a central wavelength of 1550 nm;

The first optical fiber coupler c1 is used to divide the linear frequency-sweeping light into a first frequency-sweeping light signal and a second frequency-sweeping light signal; the two frequency-sweeping light signals enter the auxiliary interference module (branch) and the main interference module (branch) respectively;

An auxiliary interference module receives the first frequency swept optical signal to generate a clock signal; a Mach-Zehnder interferometer can be used as an auxiliary interferometer to interfere with the first frequency swept optical signal to generate a clock signal;

The main interference module receives the second frequency sweep optical signal to generate a beat frequency interference signal;

When the second frequency swept optical signal enters the main interference module, the Mach-Zehnder interferometer can be used as the main interferometer to interfere with the first frequency swept optical signal and then input to the second optical fiber coupler c2; or Directly input the second frequency swept optical signal to the second optical fiber coupler c2;

The second optical fiber coupler c2 divides the second swept optical signal into two channels. One channel obtains the reference arm signal through the polarization controller and enters the third optical fiber coupler c3; the other channel passes through the large core diameter multi-mode circulator. The first port, the fiber to be tested, the second port of the large core diameter multimode circulator, the third port of the large core diameter multimode circulator, and the mode matcher obtain the signal arm signal and enter The third optical fiber coupler c3; among them, due to the optical frequency domain reflection OFDR effect, the Rayleigh backscattering signal in the signal arm and the optical signal in the reference arm introduce time delay due to the optical path difference, so the two paths The optical signals carried by the signals have different frequencies and will be mixed in the third optical fiber coupler c3.

After the mixed signal enters the polarization beam splitter, it is divided into two mutually orthogonal lights, S light and P light (to eliminate the impact of polarization fading effect), and beat frequency interference occurs on the photosensitive surface of the photodetector, and at the same time The photodetector converts the interference light signal into an electrical signal and inputs it into the data acquisition card to complete the signal collection.

The DAQ data acquisition module, which may be a DAQ data acquisition card, for example, receives the clock signal and the beat frequency interference signal, and outputs them to the data processing module;

The data processing module, for example, can be a device with computing capabilities such as a personal computer or a server. Based on the signal data received by the data acquisition module, the temperature data of the large core diameter multimode optical fiber is calculated through a predetermined algorithm.

This temperature measurement device requires two wavelength scans when performing temperature sensing. Once as reference data, and once as measured data when the temperature changes. The raw data obtained for each scan is the distribution of scattered light and reflected light sets over the scanning wavelength range along the entire length of the sensing fiber, so it needs to be converted into the distribution of scattered and reflected light intensity along the length of the fiber through Fourier transformation. , and then perform a cross-correlation operation on the reference data and the measured data to obtain the change information of the frequency shift of the Rayleigh scattering spectrum. Since the shift of the spectrum is caused by changes in the external temperature, the temperature change information on the entire energy-transmitting optical fiber to be measured can be obtained. In this way, the temperature data of large core diameter multimode optical fiber can be effectively calculated.

Through the large core diameter multimode optical fiber temperature measurement device provided by the present invention, the temperature measurement of the large core diameter multimode optical fiber can be realized efficiently and quickly. The system has low complexity, low cost and high efficiency. At the same time, it solves the problem of large core diameter multimode optical fiber. When using multi-mode fiber for temperature sensing, there is a problem of excessive insertion loss when transmitting optical signals from a large core diameter multi-mode fiber to a small core diameter single mode fiber.

Preferably, Figure 3 shows a schematic structural diagram of the multimode device part of the temperature measurement device of a large core diameter multimode optical fiber. We have improved the mode matcher and used a two-stage series mode matcher to perform mode conversion.

Referring to Figure 3, we have improved the single-mode OFDR system based on the large-core diameter multi-mode energy transmission fiber. In it, the frequency-sweeping light enters port 1 of the large-core diameter multi-mode circulator from the single-mode fiber (the optical signal passes from the small-core diameter single-mode fiber to When the mode fiber is introduced into the large core diameter multimode fiber, the insertion loss is extremely small and can be ignored), it enters the large core diameter multimode energy transmission fiber of the fiber to be tested through the 2 port of the circulator, and at the same time, the 2 port receives the Rayleigh returned from the fiber to be tested. The signal is scattered and output through port 3 of the circulator. At this time, the output Rayleigh scattering signal is transmitted in a 105μm/125μm special multi-mode optical fiber and needs to be converted by a mode matcher before it can be connected to a single-mode coupler. Since the core diameter difference is too large when directly matching 105μm/125μm special multimode fiber and 10μm/125μm single-mode fiber, resulting in excessive insertion loss, a two-stage mode matcher is used: the first-stage mode matcher is 105μm/ 125μm special multimode fiber is converted to 62.5μm/125μ, and the second-stage mode matcher is 62.5μm/125μ to 10μm/125μm. After the two-stage mode matcher, the Rayleigh scattering signal is output from the single-mode fiber and enters the single-mode coupler. middle. The above-mentioned large core diameter multimode circulator is directly connected to the energy transmission fiber to be tested, and then converted and output through a two-stage mode matcher, which reduces the insertion of optical signals from the large core diameter multimode fiber into the small core diameter single mode fiber. Loss, this method only changes some key components in the OFDR single-mode system, and can realize temperature sensing of large-core multi-mode energy-transmitting optical fibers, which reduces costs while expanding OFDR applications.

On the other hand, the present invention proposes a temperature measurement method for a large core diameter multimode optical fiber. As can be seen from Figures 1-2, the method specifically includes:

Using a swept frequency light source to provide the device with linear swept frequency light with a central wavelength of 1550 nm;

The first optical fiber coupler is used to divide the linear frequency sweep light into a first frequency sweep optical signal and a second frequency sweep optical signal; the two frequency sweep optical signals enter the auxiliary interference branch and the main interference branch respectively;

An auxiliary interferometer is used to receive the first frequency swept optical signal to generate a clock signal; a Mach-Zehnder interferometer can be used as an auxiliary interferometer to interfere with the first frequency swept optical signal to generate a clock signal;

The second frequency-sweeping optical signal is received by a main interferometer to generate a beat frequency interference signal; when the second frequency-sweeping optical signal enters the main interference module, a Mach-Zehnder interferometer can be used as the main interferometer to interfere with the first frequency-sweeping optical signal, and then input to the second optical fiber coupler c2; or the second frequency-sweeping optical signal is directly input to the second optical fiber coupler c2;

The second optical fiber coupler c2 divides the second swept frequency optical signal into two channels. One channel obtains the reference arm signal through the polarization controller and enters the third optical fiber coupler c3; the other channel passes through the large core diameter multi-mode circulator. The first port, the fiber to be tested, the second port of the large core diameter multimode circulator, the third port of the large core diameter multimode circulator, and the mode matcher obtain the signal arm signal and enter The third optical fiber coupler c3; among them, due to the optical frequency domain reflection OFDR technology, the Rayleigh backscattering signal in the signal arm and the optical signal in the reference arm introduce time delay due to the optical path difference, so the two paths The optical signals carried by the signals have different frequencies and will be mixed in the third optical fiber coupler c3.

After the mixed signal enters the polarization beam splitter, it is divided into two mutually orthogonal lights, S light and P light (to eliminate the impact of polarization fading effect), and beat frequency interference occurs on the photosensitive surface of the photodetector, and at the same time The photodetector converts the interference light signal into an electrical signal and connects it to the data acquisition card to complete the signal collection.

The clock signal and the beat frequency interference signal are received by a data acquisition module to generate temperature data of the large-core multimode optical fiber.

This temperature measurement method requires two wavelength scans when performing temperature sensing. Once as reference data, and once as measured data when the temperature changes. The raw data obtained for each scan is the distribution of scattered light and reflected light sets over the entire length of the sensing fiber in the scanning wavelength range, so it needs to be converted into the distribution of scattered and reflected light intensity along the length of the fiber through Fourier transformation. , and then perform a cross-correlation operation on the reference data and the measured data to obtain the change information of the frequency shift of the Rayleigh scattering spectrum. Since the shift of the spectrum is caused by changes in external temperature, the temperature change information on the entire energy-transmitting optical fiber to be measured can be obtained. In this way, the temperature data of large core diameter multimode optical fiber can be effectively calculated.

See Figure 3. Based on the large core diameter multi-mode energy transmission fiber, we have improved the single-mode OFDR system. In it, the swept light enters port 1 of the large core diameter multi-mode circulator from the single mode fiber (the optical signal passes from the small core diameter When the single-mode fiber is introduced into the large-core diameter multi-mode fiber, the insertion loss is extremely small and can be ignored), it enters the large-core diameter multi-mode energy transmission fiber of the fiber to be tested through the 2-port of the circulator, and at the same time, the 2-port receives the Ray signal returned from the fiber to be tested. The scattered signal is output through port 3 of the circulator. At this time, the output Rayleigh scattering signal is transmitted in a 105μm/125μm special multi-mode optical fiber and needs to be converted by a mode matcher before it can be connected to a single-mode coupler. Since the core diameter difference is too large when directly matching 105μm/125μm special multimode fiber and 10μm/125μm single-mode fiber, resulting in excessive insertion loss, a two-stage mode matcher is used: the first-stage mode matcher is 105μm/ 125μm special multimode fiber is converted to 62.5μm/125μ, and the second-stage mode matcher is 62.5μm/125μ to 10μm/125μm. After the two-stage mode matcher, the Rayleigh scattering signal is output from the single-mode fiber and enters the single-mode coupler. middle. The above-mentioned large core diameter multimode circulator is directly connected to the energy transmission fiber to be tested, and then converted and output through a two-stage mode matcher, which reduces the insertion of optical signals from the large core diameter multimode fiber into the small core diameter single mode fiber. Loss, this method only changes some key components in the OFDR single-mode system, and can realize temperature sensing of large-core multi-mode energy-transmitting optical fibers, which reduces costs while expanding OFDR applications.

Through the large core diameter multimode optical fiber temperature measurement device provided by the present invention, the temperature measurement of the large core diameter multimode optical fiber can be realized efficiently and quickly. The system has low complexity, low cost and high efficiency. At the same time, it solves the problem of large core diameter multimode optical fiber. When using multi-mode fiber for temperature sensing, there is a problem of excessive insertion loss when transmitting optical signals from a large core diameter multi-mode fiber to a small core diameter single mode fiber.

The division of modules in the above embodiments of the present invention is schematic and is only a logical function division. There may be other division methods in actual implementation. In addition, each functional module in each embodiment of the present application may be integrated into one processor, or may exist physically separately, or two or more modules may be integrated into one module. The above integrated modules may be implemented in the form of hardware or in the form of software functional modules.

Electronic devices according to embodiments of the present invention exist in various forms, including but not limited to:

(1) Mobile communication devices: These devices are characterized by their mobile communication functions and their main purpose is to provide voice and data communications. These terminals include: smart phones (such as iPhone), multimedia phones, functional phones, and low-end phones.

(2) Ultra-mobile personal computer equipment: This type of equipment belongs to the category of personal computers, has computing and processing functions, and generally also has mobile Internet features. Such terminals include: PDA, MID and UMPC devices, such as iPad.

(3) Portable entertainment devices: These devices can display and play multimedia content. Such devices include: audio and video players (such as iPod), handheld game consoles, e-books, as well as smart toys and portable car navigation devices.

(4) Server: A device that provides computing services. The server is composed of a processor 1010, a hard disk, a memory, a system bus, etc. The server is similar to a general computer architecture, but due to the need to provide highly reliable services, it has to deal with processing power, stability, etc. It has higher requirements in terms of performance, reliability, security, scalability, manageability, etc.

(5) Other electronic devices with data interaction functions.

The device embodiments described above are only illustrative. The modules described as separate components may or may not be physically separated. The components shown as modules may or may not be physical modules, that is, they may be located in one place. , or it can be distributed to multiple network modules. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment. Persons of ordinary skill in the art can understand and implement the method without any creative effort.

Embodiments of the present invention provide a non-volatile computer-readable storage medium. The non-volatile computer-readable storage medium stores program instructions. When the electronic device executes the program instructions, it is used to execute the methods and methods in the above method embodiments. step.

Embodiments of the present invention provide a computer program product, wherein the computer program product includes a computer program stored on a non-transitory computer-readable storage medium, and the computer program includes program instructions, wherein when the program instructions are executed by an electronic device, The electronic device is caused to perform the method in any of the above method embodiments.

The functional modules in the various embodiments of the present invention may be integrated into one processing unit, or each module may exist physically separately, or two or more modules may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of hardware plus software functional units.

The above-mentioned integrated unit implemented in the form of a software functional unit can be stored in a computer-readable storage medium. The above-mentioned software functional unit is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) or an intelligent terminal device or a processor (Processor) to perform some steps of the methods of various embodiments of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (Read-Only Memory, ROM), random access memory (Random Access Memory, RAM), disk or optical disk and other media that can store program codes.

In the above-mentioned embodiments provided by the present invention, it should be understood that the disclosed devices and methods can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of modules is only a logical function division. In actual implementation, there may be other division methods. For example, multiple modules or components may be combined or may be Integrated into another system, or some features can be ignored, or not implemented.

Modules described as separate components may or may not be physically separated, and components shown as modules may or may not be physical modules, that is, they may be located in one place, or they may be distributed to multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

The above are only embodiments of the present invention, but do not limit the patent scope of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still implement the foregoing specific Modify the technical solution recorded in the method, or make equivalent replacements for some of the technical features. Any equivalent structures made using the contents of the description and drawings of the present invention and used directly or indirectly in other related technical fields shall likewise fall within the scope of patent protection of the present invention.

Claims (2)

1. A temperature measurement device for large core diameter multimode optical fiber, characterized in that the device includes: a frequency swept light source for providing the device with linear frequency swept light with a center wavelength of 1550 nm; A first optical fiber coupler, used to divide the linear frequency swept light into a first frequency swept optical signal and a second frequency swept optical signal; an auxiliary interference module, receiving the first frequency-sweeping optical signal to generate a clock signal; The main interference module receives the second frequency sweep optical signal to generate a beat frequency interference signal; A data acquisition module receives the clock signal and the beat frequency interference signal, and outputs them to the data processing module; A data processing module, which generates temperature data of the large-core multimode optical fiber based on the signal received by the data acquisition module; Wherein, the main interference module includes: a second optical fiber coupler, a polarization controller, a large core diameter multi-mode circulator, an optical fiber to be tested, a mode matcher, a third optical fiber coupler, a polarization beam splitter, and a photodetector; Wherein: the second optical fiber coupler divides the second frequency swept optical signal into two channels, one channel obtains the reference arm signal through the polarization controller, and enters the third optical fiber coupler; the other channel passes through the large core diameter The first port of the multimode circulator, the optical fiber to be tested, the second port of the large core diameter multimode circulator, the third port of the large core diameter multimode circulator, and the mode matcher obtain the signal The arm signal enters the third optical fiber coupler; The third optical fiber coupler mixes the reference arm signal and the signal arm signal, and outputs them to the polarization beam splitter to obtain a first optical signal and a second optical signal that are orthogonal to each other, and The first optical signal and the second optical signal are output to the photodetector; The photodetector converts the first optical signal and the second optical signal into electrical signals and outputs them to the data acquisition module; The mode matcher comprises: a first-stage mode matcher and a second-stage mode matcher connected in series; wherein: the input end of the first-stage mode matcher is connected to a 105μm/125μm special multimode optical fiber, and the output end is connected to a 62.5μm/125μm multimode optical fiber; The input end of the second-stage mode matcher is connected to the 62.5μm/125μm multi-mode optical fiber, and the output end is connected to the 10μm/125μm single-mode optical fiber; Wherein, the optical fiber to be tested includes a large core diameter multi-mode energy transmission optical fiber; The auxiliary interference module includes a Mach-Zehnder interferometer. 2. A temperature measurement method for large core diameter multimode optical fiber, characterized in that the method includes: Utilizing a frequency swept light source to provide linear frequency swept light with a central wavelength of 1550nm for the temperature measurement device of claim 1; Using a first optical fiber coupler to divide the linear frequency sweep light into a first frequency sweep optical signal and a second frequency sweep optical signal; Using an auxiliary interference module to receive the first frequency sweep optical signal to generate a clock signal; Utilize the main interference module to receive the second frequency sweep optical signal to generate a beat frequency interference signal; Utilize a data acquisition module to receive the clock signal and the beat frequency interference signal to generate temperature data of the large core diameter multimode optical fiber; Wherein, the main interference module includes: a second fiber coupler, a polarization controller, a large-core multimode circulator, an optical fiber to be tested, a mode matcher, a third fiber coupler, a polarization beam splitter, and a photodetector; wherein: the second fiber coupler divides the second frequency-sweeping optical signal into two paths, one path obtains a reference arm signal via the polarization controller and enters the third fiber coupler; the other path obtains a signal arm signal via the first port of the large-core multimode circulator, the optical fiber to be tested, the second port of the large-core multimode circulator, the third port of the large-core multimode circulator, and the mode matcher and enters the third fiber coupler; The third optical fiber coupler mixes the reference arm signal and the signal arm signal, and outputs the mixed signals to the polarization beam splitter to obtain a first optical signal and a second optical signal orthogonal to each other, and outputs the first optical signal and the second optical signal to the photodetector; The photodetector converts the first optical signal and the second optical signal into electrical signals and outputs them to the data acquisition module; Wherein, the mode matcher includes: a first-level mode matcher and a second-level mode matcher connected in series; wherein: the input end of the first-level mode matcher is connected to a 105 μm/125 μm special multi-mode optical fiber, and the output end Connect 62.5μm/125μm multi-mode optical fiber; The input end of the second-stage mode matcher is connected to the 62.5 μm/125 μm multi-mode optical fiber, and the output end is connected to the 10 μm/125 μm single-mode optical fiber.