CN116678513A - Fiber bragg grating-based temperature measurement system and temperature measurement method - Google Patents
Fiber bragg grating-based temperature measurement system and temperature measurement method Download PDFInfo
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- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
- G01K11/3206—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres at discrete locations in the fibre, e.g. using Bragg scattering
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Abstract
The application relates to a temperature measurement system and a temperature measurement method based on fiber bragg gratings, wherein the system comprises: the device comprises a light source, an optical fiber measuring module, a circuit driving module, a photoelectric conversion module and a data processing module; the light source is used for generating an initial light signal and transmitting the initial light signal to the optical fiber measurement module; the circuit driving module is used for generating an electric pulse signal and sending the electric pulse signal to the optical fiber measuring module and the data processing module; the optical fiber measurement module is used for obtaining a modulated optical signal according to the initial optical signal and the electric pulse signal, transmitting the modulated optical signal, and carrying out self-heating to change the period and the effective refractive index of the optical fiber grating so as to obtain a reflected optical signal; the photoelectric conversion module is used for converting the reflected light signals to obtain detection wave signals and sending the detection wave signals to the data processing module; the data processing module is used for demodulating according to the modulated optical signal and the detection wave signal to obtain temperature information. The application collects and demodulates wavelength information at the same time, and realizes on-line temperature measurement.
Description
Technical Field
The application relates to the technical field of temperature measurement, in particular to a temperature measurement system and a temperature measurement method based on fiber bragg gratings.
Background
The fiber grating temperature sensing technology is an important branch of the fiber grating sensing technology, and has been developed from the beginning of the 70 th century to the present. Temperature sensing is important in application scenarios such as marine observation, mine temperature monitoring, volcanic disaster monitoring, extremely low temperature environment monitoring, etc., under these scenarios, electronic temperature sensors often have difficulty in good performance due to limitations of own characteristics. Compared with the traditional electronic temperature sensor, the fiber bragg grating temperature sensor has the advantages of corrosion resistance, electromagnetic interference resistance, small size, large dynamic range and the like, so that the fiber bragg grating temperature sensor has good application potential.
Currently, in the fiber bragg grating temperature sensing technology, scientific researchers improve the performance of a fiber bragg grating temperature sensor from the aspects of fiber bragg grating materials, light sources, inscription technology, packaging technology and the like, but the demodulation method is mainly based on the central wavelength drift amount, and the temperature change is obtained by measuring the central wavelength drift amount of an optical signal after the optical signal passes through a temperature field. In the demodulation method based on the center wavelength drift, the temperature change of 1 ℃ causes the center wavelength drift of 10pm, so that the temperature is measured by the method, and the measurement accuracy of the temperature is limited by the spectrum measurement accuracy and the center wavelength peak finding algorithm.
In the existing fiber grating temperature measurement research, the acquisition and demodulation of wavelength information are often completed in two steps, firstly, the wavelength information of an optical signal for measuring temperature is acquired, and then, the wavelength drift amount is demodulated by a certain demodulation algorithm to obtain the temperature information to be measured. The wavelength information acquired by the spectrometer cannot be directly input into the data processing unit for real-time demodulation, but the carrier wavelength information is firstly downloaded from the spectrometer to the storage device, then the storage device is connected to the data processing unit for demodulation of the wavelength information, and therefore, the method has the obvious defect that real-time online temperature measurement cannot be realized, and therefore, certain application scenes with requirements on real-time performance cannot be met.
Disclosure of Invention
In view of the foregoing, it is necessary to provide a temperature measurement system and a temperature measurement method based on fiber gratings, so as to solve the problem that the collection and demodulation of wavelength information in the prior art are separately completed and real-time online temperature measurement cannot be realized.
In order to achieve the technical purpose, the application adopts the following technical scheme:
in a first aspect, the present application provides a fiber grating-based temperature measurement system, comprising: the device comprises a light source, an optical fiber measuring module, a circuit driving module, a photoelectric conversion module and a data processing module; the light source is connected with the optical fiber measuring module through optical fibers; the optical fiber measuring module is respectively connected with the circuit driving module and the photoelectric conversion module; the data processing module is respectively connected with the circuit driving module and the photoelectric conversion module;
the optical source is used for generating an initial optical signal and transmitting the initial optical signal to the optical fiber measurement module;
the circuit driving module is used for generating an electric pulse signal and sending the electric pulse signal to the optical fiber measuring module and the data processing module;
the optical fiber measurement module is used for obtaining a modulated optical signal according to the initial optical signal and the electric pulse signal, transmitting the modulated optical signal, and carrying out self-heating to change the period and the effective refractive index of the optical fiber grating so as to obtain a reflected optical signal;
the photoelectric conversion module is used for converting the reflected light signals to obtain detection wave signals and sending the detection wave signals to the data processing module;
the data processing module is used for demodulating according to the modulated optical signal and the detection wave signal to obtain temperature information.
In some possible implementations, the fiber optic measurement module includes an optical modulator, a circulator, a doped fiber, and a fiber grating; the optical modulator, the circulator and the doped optical fiber are sequentially connected in sequence; the fiber bragg grating is inscribed on the doped fiber; the light modulator is connected with the light source through an optical fiber; the optical modulator is connected with the circuit driving module through a data line;
the optical modulator is used for modulating the initial optical signal according to the electric pulse signal to obtain a modulated optical signal;
the circulator is used for transmitting and isolating the modulated optical signal and the reflected optical signal;
the doped optical fiber is used for generating heat energy according to the modulated optical signal to perform self-heating to change the temperature in the optical fiber;
the fiber bragg grating is used for reflecting the modulated optical signal to obtain a reflected optical signal.
In some possible implementations, the photoelectric conversion module includes: a filter, a first converter, a second converter; the filter, the first converter and the second converter are sequentially connected in sequence; the filter is connected with the circulator through an optical fiber; the data processing module is connected with the second converter through a data line;
the filter is used for obtaining an optical signal containing light intensity information according to the reflected optical signal;
the first converter is used for converting the optical signal containing the light intensity information into an electric signal;
the second converter is used for converting the electric signal into a detection wave signal of the digital signal.
In some possible implementations, the light source is a semiconductor pump light source, and pump light emitted by the semiconductor pump light source is transmitted to the optical modulator through the optical fiber.
In some possible implementations, the data processing module is an intelligent computer terminal that dynamically demodulates and displays temperature information in real time according to the modulated optical signal and the probe wave signal.
In some possible implementations, the electrical pulse signal generated by the circuit driving module is a periodic signal.
In some possible implementations, the filter is an edge filter.
In some possible implementations, the first converter is a photoelectric converter.
In some possible implementations, the second converter is an analog-to-digital converter.
In a second aspect, the present application further provides a fiber grating-based temperature measurement method, based on the fiber grating-based temperature measurement system according to any one of the possible implementation manners, including:
modulating an initial optical signal sent by a light source and an electric pulse signal sent by a circuit driving module to obtain a modulated optical signal;
the modulated optical signal is subjected to self-heating through an optical fiber measuring module and reflected to obtain a reflected optical signal;
converting the reflected light signal into a detection wave signal by a photoelectric conversion module;
and demodulating the electric pulse signal and the detection wave signal through a data processing module to obtain real-time temperature information.
The beneficial effects of adopting the embodiment are as follows: the application relates to a temperature measurement system and a temperature measurement method based on fiber bragg gratings, wherein the system comprises: the device comprises a light source, an optical fiber measuring module, a circuit driving module, a photoelectric conversion module and a data processing module; the light source is connected with the optical fiber measuring module through optical fibers; the optical fiber measuring module is respectively connected with the circuit driving module and the photoelectric conversion module; the data processing module is respectively connected with the circuit driving module and the photoelectric conversion module; the optical source is used for generating an initial optical signal and transmitting the initial optical signal to the optical fiber measurement module; the circuit driving module is used for generating an electric pulse signal and sending the electric pulse signal to the optical fiber measuring module and the data processing module; the optical fiber measurement module is used for obtaining a modulated optical signal according to the initial optical signal and the electric pulse signal, transmitting the modulated optical signal, and carrying out self-heating to change the period and the effective refractive index of the optical fiber grating so as to obtain a reflected optical signal; the photoelectric conversion module is used for converting the reflected light signals to obtain detection wave signals and sending the detection wave signals to the data processing module; the data processing module is used for demodulating according to the modulated optical signal and the detection wave signal to obtain temperature information. According to the temperature measurement system and the temperature measurement method based on the fiber bragg grating, an initial optical signal generated by a light source is modulated by an electric pulse signal generated by a circuit driving module to obtain a modulated optical signal, the modulated optical signal is transmitted by an optical fiber measurement module to be self-heated and reflected to obtain a reflected optical signal, then the acquisition of wavelength information of the reflected optical signal is realized by a photoelectric conversion module, reflected light containing the wavelength information is converted into a detection wave signal, and the detection wave signal and the electric pulse signal are demodulated by a data processing module, so that standing horse demodulation is realized after sensing information acquisition is realized, and real-time online temperature measurement is realized.
Drawings
FIG. 1 is a schematic diagram of a temperature measurement system based on fiber gratings according to an embodiment of the present application;
FIG. 2 is a schematic diagram illustrating an embodiment of modulating an optical signal and detecting a wave signal in a data processing unit according to the present application;
fig. 3 is a schematic flow chart of an embodiment of a fiber grating-based temperature measurement method according to the present application.
Detailed Description
The following detailed description of preferred embodiments of the application is made in connection with the accompanying drawings, which form a part hereof, and together with the description of the embodiments of the application, are used to explain the principles of the application and are not intended to limit the scope of the application.
In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.
Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Those of skill in the art will explicitly and implicitly appreciate that the embodiments described herein may be combined with other embodiments.
The application provides a temperature measurement system and a temperature measurement method based on fiber bragg gratings, which are respectively described below.
Referring to fig. 1, fig. 1 is a schematic structural diagram of an embodiment of a temperature measurement system based on a fiber grating 10 according to the present application. In one embodiment of the present application, a temperature measurement system based on fiber grating 10 is disclosed, comprising: the device comprises a light source 1, an optical fiber measuring module, a circuit driving module 3, a photoelectric conversion module and a data processing module 4; the light source 1 is connected with the optical fiber measuring module through optical fibers; the optical fiber measuring module is respectively connected with the circuit driving module 3 and the photoelectric conversion module; the data processing module 4 is respectively connected with the circuit driving module 3 and the photoelectric conversion module;
the optical source 1 is used for generating an initial optical signal and transmitting the initial optical signal to the optical fiber measurement module;
the circuit driving module 3 is used for generating an electric pulse signal and sending the electric pulse signal to the optical fiber measuring module and the data processing module 4;
the optical fiber measurement module is used for obtaining a modulated optical signal according to the initial optical signal and the electric pulse signal, transmitting the modulated optical signal, and carrying out self-heating to change the period and the effective refractive index of the optical fiber grating 10 so as to obtain a reflected optical signal;
the photoelectric conversion module is used for converting the reflected light signals to obtain detection wave signals and sending the detection wave signals to the data processing module 4;
the data processing module 4 is configured to demodulate the modulated optical signal and the probe signal to obtain temperature information.
In the above embodiment, the light source 1 generates an initial light signal, the initial light signal is sent to the optical fiber measurement module through the optical fiber, the optical fiber measurement module modulates the initial light signal according to the electric pulse signal generated by the circuit driving module 3 to obtain a modulated light signal with periodicity, and transmits the modulated light signal to realize self-heating, and the wavelength of the modulated light signal changes due to heating, and then the reflected light signal is obtained.
The electric pulse signal sent to the optical fiber measuring module by the circuit driving module 3 is used for modulating the initial optical signal, and the electric pulse signal sent to the data processing module 4 is used for demodulation and determining real-time temperature information. That is, the circuit driving module sends out an electric pulse signal to modulate the initial optical signal to obtain a periodically modulated optical signal, the modulated optical signal is subsequently used for heating an optical fiber to obtain temperature information, the heating can change the period and the effective refractive index of the optical fiber grating 10, so that the phase of the reflected optical signal reflected by the optical fiber grating 10 is changed, the phase change condition of the reflected optical signal can be determined by taking the electric pulse signal as a reference, and the temperature information is measured.
Since the electric pulse signal is an electric signal and the reflected light signal is an optical signal, the electric signal needs to be demodulated when demodulating, so that the light intensity information is obtained by the photoelectric conversion module and converted into a digital detection wave signal, and the detection wave signal is sent to the data processing module 4.
The data processing module 4 compares the wavelength change condition of the detection wave signal according to the electric pulse signal, and determines the temperature information according to the wavelength change condition of the detection wave signal, so that the acquisition and demodulation of the wavelength information can be realized at the same time, and the temperature information is obtained in real time.
Compared with the prior art, the temperature measurement system based on the fiber bragg grating 10 provided in this embodiment includes: the device comprises a light source 1, an optical fiber measuring module, a circuit driving module 3, a photoelectric conversion module and a data processing module 4; the light source 1 is connected with the optical fiber measuring module through optical fibers; the optical fiber measuring module is respectively connected with the circuit driving module 3 and the photoelectric conversion module; the data processing module 4 is respectively connected with the circuit driving module 3 and the photoelectric conversion module; the optical source 1 is used for generating an initial optical signal and transmitting the initial optical signal to the optical fiber measurement module; the circuit driving module 3 is used for generating an electric pulse signal and sending the electric pulse signal to the optical fiber measuring module and the data processing module 4; the optical fiber measurement module is used for obtaining a modulated optical signal according to the initial optical signal and the electric pulse signal, transmitting the modulated optical signal, and carrying out self-heating to change the period and the effective refractive index of the optical fiber grating 10 so as to obtain a reflected optical signal; the photoelectric conversion module is used for converting the reflected light signals to obtain detection wave signals and sending the detection wave signals to the data processing module 4; the data processing module 4 is configured to demodulate the modulated optical signal and the probe signal to obtain temperature information. According to the temperature measurement system and the temperature measurement method based on the fiber bragg grating 10, an initial optical signal generated by the light source 1 is modulated by an electric pulse signal generated by the circuit driving module 3 to obtain a modulated optical signal, the modulated optical signal is transmitted by the fiber bragg grating measuring module to be self-heated and reflected to obtain a reflected optical signal, then the acquisition of wavelength information of the reflected optical signal is realized by the photoelectric conversion module, reflected light containing the wavelength information is converted into a detection wave signal, and the detection wave signal and the electric pulse signal are demodulated by the data processing module 4, so that standing horse demodulation is realized after sensing information acquisition is realized, and real-time online temperature measurement is realized.
In some embodiments of the application, the fiber optic measurement module includes an optical modulator 2, a circulator 8, a doped fiber 9, and a fiber grating 10; the optical modulator 2, the circulator 8 and the doped optical fiber 9 are sequentially connected in sequence; the fiber grating 10 is inscribed on the doped fiber 9; the light modulator 2 is connected with the light source 1 through an optical fiber; the optical modulator 2 is connected with the circuit driving module 3 through a data line;
the optical modulator 2 is used for modulating the initial optical signal according to the electric pulse signal to obtain a modulated optical signal;
the circulator 8 is used for transmitting and isolating the modulated optical signal and the reflected optical signal;
the doped optical fiber 9 is used for generating heat energy according to the modulated optical signal to perform self-heating to change the temperature in the optical fiber;
the fiber grating 10 is used for reflecting the modulated optical signal to obtain a reflected optical signal.
In the above-described embodiment, the optical modulator 2 may generate an electric pulse signal to modulate the intensity of the initial optical signal, and as a preferred embodiment, the optical modulator 2 of the present application may include an acousto-optic modulator, an electro-optic modulator, an all-optical modulator, etc., which the present application is not limited to further.
The circulator 8 transmits incident light entering any one port thereof into the multi-port device of the next port in order of direction determined by the static bias magnetic field, and can unidirectionally transmit high-frequency signal energy.
The doped optical fiber 9 can absorb the power of the modulated optical signal and convert the power into heat energy, so as to realize self-heating of the optical fiber and periodical change of temperature, and as a preferred embodiment, the doped optical fiber 9 of the present application can be an erbium-doped optical fiber, a neodymium-doped optical fiber, a cobalt-doped optical fiber, etc., and the doped optical fiber 9 of the present application is a cobalt-doped optical fiber.
As a preferred embodiment, the absorption coefficient of the cobalt-doped optical fiber is 0.71dB/cm, and the absorption coefficient is relatively large, so that the temperature rise of the optical fiber after absorbing the power of the pump light is high enough; the working wavelength is 1250-1620nm and the length is set to 10cm.
The fiber grating 10 is a single grating, and the wavelength can be matched and selected according to the wavelength of the light source 1. As a preferred embodiment, the wavelength of the fiber grating 10 is 1560nm, which matches the wavelength of the semiconductor pump light source 1, and the length is 5mm, which is located in the rear half of the doped fiber 9. When the fiber grating 10 is heated, the period and the effective refractive index of the fiber grating change to form a grating different from the original fiber grating 10, so that the optical signal has a phase change after being reflected by the fiber grating 10. When the ambient temperature at the fiber grating 10 is different, the amount of phase change of the optical signal will also be different.
In some embodiments of the present application, a photoelectric conversion module includes: a filter 7, a first converter 6, a second converter 5; the filter 7, the first converter 6 and the second converter 5 are sequentially connected in sequence; the filter 7 is connected with the circulator 8 through an optical fiber; the data processing module 4 is connected with the second converter 5 through a data line;
wherein the filter 7 is used for obtaining an optical signal containing light intensity information according to the reflected optical signal;
the first converter 6 is used for converting an optical signal containing light intensity information into an electric signal;
the second converter 5 is for converting an electrical signal into a probe signal of a digital signal.
In the above embodiment, the filter 7 converts the wavelength information of the reflected light signal into light intensity information, and the resultant light signal is still an optical signal, and the light intensity information is easier to analyze than the wavelength information. The first converter 6 can convert the optical signal into an electrical signal, and realize photoelectric conversion. The second converter 5 converts the electric signal into a digital signal, and the demodulation and the real-time temperature information determination are more conveniently realized through the digital signal. The edge filter inputs wavelength information of the reflected light signal, outputs a light signal with light intensity information, and the light intensity changes periodically.
In some embodiments of the application, the light source 1 is a semiconductor pump light source, and pump light emitted by the semiconductor pump light source is transmitted to the acousto-optic modulator through an optical fiber.
In the above embodiment, the semiconductor pump light source is a high-power pump light source for providing a temperature measurement signal to the system and providing excitation power to the doped optical fiber 9, and as a preferred embodiment, the semiconductor pump light source may be a semiconductor laser, a YAG laser, or the like, which is not limited in the present application.
As a preferred embodiment, the power of the semiconductor pump light source is set to 1500mw, and too small power can cause the temperature change of the optical fiber to be small, and the response temperature measurement sensitivity is high; the wavelength of light was set to 1560nm.
In some embodiments of the present application, the data processing module 4 is an intelligent computer terminal that dynamically demodulates and displays temperature information in real time according to the modulated optical signal and the probe wave signal.
In the above embodiment, the intelligent computer terminal may be a general computer, or may be other devices with analysis functions, such as a single chip microcomputer, and may be used for dynamically demodulating phase information and displaying the measured temperature in real time.
Referring to fig. 2, fig. 2 is a schematic diagram illustrating a comparison between an embodiment of a modulated optical signal and a detected wave signal in a data processing unit according to the present application, where an intelligent computer terminal processes the modulated optical signal and the detected wave signal to obtain a phase difference Δt between the modulated optical signal and the detected wave signal, and demodulates the phase difference Δt to obtain temperature field information at the fiber grating 10. The measurement accuracy of the intelligent computer terminal to the phase is higher than that of the spectrometer to the wavelength, so that the high-accuracy temperature measurement can be realized by utilizing phase difference demodulation, and the accuracy of the temperature measured by the method is improved.
In some embodiments of the present application, the electrical pulse signal generated by the circuit driving module 3 is a periodic signal.
In the above embodiment, the electric pulse signal may be a square wave signal, a rectangular wave signal, a sawtooth wave signal, a triangular wave signal, a bell wave signal, or the like, and the electric pulse signal should be a periodic signal, and may cause a periodic change in temperature when the optical fiber is self-heated. As a preferred embodiment, the electric pulse signal in the present application is a rectangular wave signal.
In some embodiments of the application, the filter 7 is an edge filter.
In the above-described embodiment, the filter 7 of the present application may convert wavelength information into light intensity information, and as a preferred embodiment, the filter 7 of the present application is an edge filter.
In some embodiments of the application, the first converter 6 is a photoelectric converter.
In the above-described embodiment, the first converter 6 of the present application converts an optical signal into an electrical signal, and as a preferred embodiment, the first converter 6 of the present application is a photoelectric converter.
In some embodiments of the application, the second converter 5 is an analog-to-digital converter.
In the above-described embodiment, the second converter 5 of the present application converts an analog electric signal into a digital electric signal, and as a preferred embodiment, the second converter 5 of the present application is an analog-to-digital converter.
Referring to fig. 3, fig. 3 is a flow chart of an embodiment of a fiber grating-based temperature measurement method according to the present application, and in a second aspect, the present application further provides a fiber grating 10-based temperature measurement method, based on the fiber grating 10-based temperature measurement system according to any one of the above possible implementation manners, including:
s301, modulating an initial optical signal sent by a light source and an electric pulse signal sent by a circuit driving module to obtain a modulated optical signal;
s302, carrying out self-heating and reflection on the modulated optical signal through an optical fiber measuring module to obtain a reflected optical signal;
s303, converting the reflected light signal into a detection wave signal through a photoelectric conversion module;
s304, demodulating the electric pulse signal and the detection wave signal through a data processing module to obtain real-time temperature information.
In the above embodiment, the initial optical signal generates periodic variation under the driving intensity of the pulse electrical signal, and when the periodically varying optical signal enters the doped optical fiber 9, the doped optical fiber 9 absorbs the energy of the optical signal due to the principle of the photo-thermal effect of the doped optical fiber 9, so as to convert part of the optical energy into heat energy, thereby realizing self-heating in the optical fiber and periodically varying the temperature in the optical fiber.
When the fiber grating 10 is heated, the period and the effective refractive index of the fiber grating change to form a grating different from the original fiber grating 10, so that the modulated optical signal has a phase change after being reflected by the grating.
The optical fiber temperature changes periodically, so that the center wavelength of the reflected light signal shifts periodically, and after the optical fiber temperature is subjected to edge filtering, the input wavelength shift amount is converted into the light intensity change amount by the edge filter, and the light intensity change amount are in a linear relation, so that the output light intensity signal also changes periodically, and a phase difference exists between the light intensity signal and the driving signal.
Since the power of the optical signal is fixed and the absorption coefficient of the doped optical fiber 9 is fixed, the temperature rise of the optical fiber grating 10 after heating is fixed, and when the environment temperature of the optical fiber grating 10 is different, the temperature of the optical fiber grating 10 after heating is also different, and the phase change amount of the optical signal is also different. The application realizes high-precision temperature measurement by utilizing the variation of the phase.
To sum up, the temperature measurement system and the temperature measurement method based on the fiber bragg grating 10 provided in the present embodiment include: the device comprises a light source 1, an optical fiber measuring module, a circuit driving module 3, a photoelectric conversion module and a data processing module 4; the light source 1 is connected with the optical fiber measuring module through optical fibers; the optical fiber measuring module is respectively connected with the circuit driving module 3 and the photoelectric conversion module; the data processing module 4 is respectively connected with the circuit driving module 3 and the photoelectric conversion module; the optical source 1 is used for generating an initial optical signal and transmitting the initial optical signal to the optical fiber measurement module; the circuit driving module 3 is used for generating an electric pulse signal and sending the electric pulse signal to the optical fiber measuring module and the data processing module 4; the optical fiber measurement module is used for obtaining a modulated optical signal according to the initial optical signal and the electric pulse signal, transmitting the modulated optical signal, and carrying out self-heating to change the period and the effective refractive index of the optical fiber grating 10 so as to obtain a reflected optical signal; the photoelectric conversion module is used for converting the reflected light signals to obtain detection wave signals and sending the detection wave signals to the data processing module 4; the data processing module 4 is configured to demodulate the modulated optical signal and the probe signal to obtain temperature information. According to the temperature measurement system and the temperature measurement method based on the fiber bragg grating 10, an initial optical signal generated by the light source 1 is modulated by an electric pulse signal generated by the circuit driving module 3 to obtain a modulated optical signal, the modulated optical signal is transmitted by the fiber bragg grating measuring module to be self-heated and reflected to obtain a reflected optical signal, then the acquisition of wavelength information of the reflected optical signal is realized by the photoelectric conversion module, reflected light containing the wavelength information is converted into a detection wave signal, and the detection wave signal and the electric pulse signal are demodulated by the data processing module 4, so that standing horse demodulation is realized after sensing information acquisition is realized, and real-time online temperature measurement is realized.
The present application is not limited to the above-mentioned embodiments, and any changes or substitutions that can be easily understood by those skilled in the art within the technical scope of the present application are intended to be included in the scope of the present application.
Claims (10)
1. A fiber grating-based temperature measurement system, comprising: the device comprises a light source, an optical fiber measuring module, a circuit driving module, a photoelectric conversion module and a data processing module; the light source is connected with the optical fiber measuring module through optical fibers; the optical fiber measuring module is respectively connected with the circuit driving module and the photoelectric conversion module; the data processing module is respectively connected with the circuit driving module and the photoelectric conversion module;
the optical source is used for generating an initial optical signal and transmitting the initial optical signal to the optical fiber measurement module;
the circuit driving module is used for generating an electric pulse signal and sending the electric pulse signal to the optical fiber measuring module and the data processing module;
the optical fiber measurement module is used for obtaining a modulated optical signal according to the initial optical signal and the electric pulse signal, transmitting the modulated optical signal, and carrying out self-heating to change the period and the effective refractive index of the optical fiber grating so as to obtain a reflected optical signal;
the photoelectric conversion module is used for converting the reflected light signals to obtain detection wave signals and sending the detection wave signals to the data processing module;
the data processing module is used for demodulating according to the modulated optical signal and the detection wave signal to obtain temperature information.
2. The fiber grating-based temperature measurement system of claim 1, wherein the fiber measurement module comprises an optical modulator, a circulator, a doped fiber, and a fiber grating; the optical modulator, the circulator and the doped optical fiber are sequentially connected in sequence; the fiber bragg grating is inscribed on the doped fiber; the light modulator is connected with the light source through an optical fiber; the optical modulator is connected with the circuit driving module through a data line;
the optical modulator is used for modulating the initial optical signal according to the electric pulse signal to obtain the modulated optical signal;
the circulator is used for transmitting and isolating the modulated optical signal and the reflected optical signal;
the doped optical fiber is used for generating heat energy according to the modulated optical signal to perform self-heating to change the temperature in the optical fiber;
the fiber bragg grating is used for reflecting the modulated optical signal to obtain the reflected optical signal.
3. The fiber grating-based temperature measurement system of claim 2, wherein the photoelectric conversion module comprises: a filter, a first converter, a second converter; the filter, the first converter and the second converter are sequentially connected in sequence; the filter is connected with the circulator through an optical fiber; the data processing module is connected with the second converter through a data line;
the filter is used for obtaining an optical signal containing light intensity information according to the reflected optical signal;
the first converter is used for converting the optical signal containing the light intensity information into an electric signal;
the second converter is used for converting the electric signal into a detection wave signal of a digital signal.
4. The fiber grating-based temperature measurement system of claim 2, wherein the light source is a semiconductor pump light source, and the pump light from the semiconductor pump light source is transmitted to the optical modulator through an optical fiber.
5. The fiber grating-based temperature measurement system according to claim 1, wherein the data processing module is an intelligent computer terminal that dynamically demodulates and displays temperature information in real time according to the modulated optical signal and the probe wave signal.
6. The fiber grating-based temperature measurement system of claim 1, wherein the electrical pulse signal generated by the circuit driving module is a periodic signal.
7. A fiber grating-based temperature measurement system according to claim 3, wherein the filter is an edge filter.
8. The fiber grating-based temperature measurement system of claim 3, wherein the first converter is a photoelectric converter.
9. A fiber grating-based temperature measurement system according to claim 3, wherein the second converter is an analog-to-digital converter.
10. A fiber grating-based temperature measurement method, based on the fiber grating-based temperature measurement system according to any one of claims 1-9, comprising:
modulating an initial optical signal sent by the light source and an electric pulse signal sent by the circuit driving module to obtain a modulated optical signal;
the modulated optical signal is subjected to self-heating through the optical fiber measuring module and reflected to obtain a reflected optical signal;
converting the reflected light signal into a detection wave signal by the photoelectric conversion module;
and demodulating the electric pulse signal and the detection wave signal through the data processing module to obtain real-time temperature information.
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