CN117191094A - Multi-parameter monitoring system and method for cascading optical fiber sensor - Google Patents

Abstract

The invention discloses a multi-parameter monitoring system and a method of a cascading optical fiber sensor, wherein a light source module of the system emits broadband light to an optical circulator, the optical circulator outputs the broadband light to the cascading optical fiber sensor, and reflected light waves of the cascading optical fiber sensor are output to a 2 x 2 coupler by the optical circulator; the 2 x 2 coupler distributes the reflected light waves into two paths averagely, wherein one path of the reflected light waves is input into each channel of the multichannel array waveguide grating, and the reflected light waves of the cascade type optical fiber sensor are converted into the transmitted light intensity in each channel of the multichannel array waveguide grating; the transmission light intensity information of each channel of the multichannel array waveguide grating is obtained by adopting an optical switch control and optical power meter and is input into a data processing module, and the data processing module directly reads the transmission light intensity information by utilizing a trained end-to-end deep neural network and outputs the corresponding interference peak-to-peak wavelength of the cascaded optical fiber sensor. The invention has the advantages of high efficiency, integration, low cost and strong anti-interference capability.

Description

Multi-parameter monitoring system and method for cascading optical fiber sensor

Technical Field

The invention relates to the technical field of cascading optical fiber sensors and multi-parameter monitoring, in particular to a cascading optical fiber sensor multi-parameter monitoring system and method.

Background

The cascade optical fiber sensor is widely applied to simultaneous measurement of multiple parameters such as temperature, pressure, stress and the like due to the remarkable advantages of high anti-interference performance, high sensitivity, low preparation cost and the like. The demodulation system for multi-parameter monitoring of the cascade optical fiber sensor is particularly important in practical use.

In general, a cascade type optical fiber sensor is formed by combining an optical fiber bragg grating and a long period optical fiber grating, or by combining a long period optical fiber grating and a fabry-perot interferometer, and the temperature cross sensitivity of the sensor structure affects multi-parameter monitoring in an industrial environment, while the multi-parameter monitoring of the cascade type optical fiber sensor usually needs to use an optical spectrum analyzer, which is also a spectrum analyzer, due to the complicated data processing and slow scanning speed and high use cost, the development of a multi-parameter monitoring system of the cascade type optical fiber sensor is limited to a great extent, and the high cost and the system complexity of an optical fiber sensing demodulation system are not suitable for being used in practical engineering application, and the peak wavelength position of the cascade type optical fiber sensor cannot be accurately obtained due to the difference and error of the system, and meanwhile, the stability and the precision loss of the whole system can be generated in the detection process.

Disclosure of Invention

In order to solve the technical problems in the prior art, the invention provides a multi-parameter monitoring system and a multi-parameter monitoring method for a cascading optical fiber sensor, which have the advantages of low cost, high efficiency and high precision, and the specific technical scheme is as follows:

a cascading fiber optic sensor multi-parameter monitoring system comprising: the optical fiber coupler comprises a light source module, an optical circulator, a cascading optical fiber sensor, a 2 x 2 coupler, a multichannel array waveguide grating, an optical switch, an optical power meter, a tubular heating furnace and a data processing module, wherein the optical circulator comprises an input end, an input end and an output end, the input end is connected to the cascading optical fiber sensor, the output end is connected to the input end of the 2 x 2 coupler, the input end is connected with the output end of the light source module, the optical circulator receives broadband light emitted by the light source module and inputs the broadband light to the cascading optical fiber sensor to form reflected light, and the reflected light is input to the 2 x 2 coupler;

an output end of the 2 x 2 coupler is connected with an input end of a multi-channel array waveguide grating, and the multi-channel array waveguide grating converts the reflected light wave offset into transmission light intensity variation in each channel;

the optical power meter is a dual-channel optical power meter, N output end channels of the multi-channel array waveguide grating are respectively connected with the input end of the optical switch and the first input end of the optical power meter, the optical switch controls the light passing condition of each channel of the multi-channel array waveguide grating, and the output end of the optical switch is connected with the second input end of the optical power meter;

the optical power meter output is connected to the data processing module, and the acquired transmission light intensity in each channel of the multichannel array waveguide grating is input to the data processing module for multi-parameter monitoring;

the cascade optical fiber sensor is placed in the tubular heating furnace.

Further, the optical spectrum analyzer is further included, the other output end of the 2 x 2 coupler is connected with the optical spectrum analyzer, reflected light waves are input into the optical spectrum analyzer, the reflection spectrum of the cascading optical fiber sensor is obtained, and the optical spectrum analyzer transmits the reflection spectrum peak wavelength data to the data processing module through the data line to serve as spectrum reference.

Further, the split ratio of the 2 x 2 coupler is 1: and 1, equally distributing the reflected light waves of the cascade optical fiber sensor into two paths.

Further, the data processing module is configured with a generation countermeasure network and a deep neural network, the generation countermeasure network performs data enhancement expansion on the transmitted light intensity information acquired from the multi-channel array waveguide grating and the data set of the reflection spectrum information of the cascade type optical fiber sensor acquired by the spectrum analyzer, and then the deep neural network demodulates the data set to acquire peak values of each interference peak of the reflection spectrum signal of the cascade type optical fiber sensor.

Further, the generating countermeasure network includes a generator that generates a data set including transmitted light intensity information and reflected spectrum peak wavelength information, and a discriminator that discriminates the authenticity of the mixed real data set and the generated data set, and finally generates an enhanced data set closest to the real data set.

Further, the deep neural network comprises an input layer, three hidden layers and an output layer, wherein the input layer is totally nine neurons, each hidden layer is totally 14 neurons, and the output layer is totally three neurons.

Furthermore, the cascade type optical fiber sensor is a cascade type optical fiber sensor combining an optical fiber Bragg grating and a Fabry-Perot interferometer, and is composed of the optical fiber Bragg grating, a capillary glass tube and a single mode fiber, wherein the optical fiber Bragg grating, the capillary glass tube and the single mode fiber are all cylindrical, the first cross section of the optical fiber Bragg grating is aligned with the first cross section of the capillary glass tube and then is subjected to discharge welding through a welding machine, the second cross section of the capillary glass tube is aligned with the first cross section of the single mode fiber and then is subjected to discharge welding through the welding machine, so that the Fabry-Perot cavity is formed between the optical fiber Bragg grating and the single mode fiber, and the optical fiber Bragg grating, the capillary glass tube and the single mode fiber are coaxial.

Further, the cladding diameter of the fiber Bragg grating is 125 mu m, the fiber core diameter is 8 mu m, the center wavelength is 1555nm, the effective reflectivity is >90%, and the sidelobe suppression ratio is 15dB; the outer diameter of the capillary glass tube is 125 mu m, and the inner diameter of the capillary glass tube is 75 mu m; the single mode fiber is SMF-28e, and the cladding diameter is 125um.

Further, the tubular heating furnace comprises a temperature control switch module and a temperature display module, the temperature control switch module starts a heating function to enable the temperature in the furnace to reach a preset temperature, and the temperature display module displays real-time temperature.

A multi-parameter monitoring method of a cascading optical fiber sensor comprises the following steps:

step one, transmitting fixed-wavelength broadband light to an optical circulator through a light source module, outputting the fixed-wavelength broadband light to a cascading optical fiber sensor by the optical circulator, and outputting reflected light waves of the cascading optical fiber sensor to a 2 x 2 coupler by the optical circulator;

step two, the 2 x 2 coupler distributes the reflected light waves into two paths on average, one path of the reflected light waves is input to a spectrum analyzer to obtain the reflection spectrum of the cascade type optical fiber sensor, and the other path of the reflected light waves is input to each channel of the multi-channel array waveguide grating to convert the reflected light waves of the cascade type optical fiber sensor into the transmitted light intensity in each channel of the multi-channel array waveguide grating;

and thirdly, acquiring transmission light intensity information of each channel of the multichannel array waveguide grating by adopting an optical power meter, inputting the transmission light intensity information into a data processing module, and directly reading the transmission light intensity information by the data processing module by utilizing a trained end-to-end deep neural network and outputting corresponding interference peak-to-peak wavelength of the cascaded optical fiber sensor.

Compared with the prior art, the invention has the advantages that; the invention discloses a complete cascade type optical fiber sensor manufacturing and demodulating framework, which combines a counter network and a deep neural network to realize data enhancement and expansion of the cascade type optical fiber sensor in a specified wavelength range and obtain high-precision peak wavelength demodulation, and the transmission light intensity information from the cascade type optical fiber sensor in each channel of an array waveguide grating is sent into the counter network to carry out data enhancement and then is sent into the deep neural network to directly obtain the transmission light intensity information and output each interference peak wavelength of the corresponding cascade type sensor.

Drawings

FIG. 1 is a schematic diagram of a cascade fiber optic sensor multi-parameter monitoring system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram showing a variation of an interference peak of the cascaded optical fiber sensor in a wavelength range of 1552-1560 nm;

FIG. 3 is a schematic diagram illustrating the fabrication of a cascaded fiber optic sensor structure according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a model structure for generating an countermeasure network according to an embodiment of the present invention;

FIG. 5 is a schematic diagram of a model structure of a deep neural network according to an embodiment of the present invention;

fig. 6 is an error variation diagram of three interference peak wavelengths and actual peak wavelengths of the cascaded optical fiber sensor in the wavelength range of 1530-1560 nm according to the embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and technical effects of the present invention more apparent, the present invention will be further described in detail with reference to the drawings and examples of the specification.

As shown in fig. 1, a cascade optical fiber sensor multi-parameter monitoring system according to an embodiment of the present invention includes: the device comprises a light source module, an optical circulator, a cascading optical fiber sensor, a 2 x 2 coupler, a spectrum analyzer, a multichannel array waveguide grating, an optical switch, an optical power meter, a tubular heating furnace and a data processing module.

The optical circulator is 1*2 and comprises an input end, an output end and an output end; the input end and the output end of the cascade optical fiber sensor are connected, the output end of the cascade optical fiber sensor is connected to the input end of the 2 x 2 coupler, the input end of the cascade optical fiber sensor is connected with the output end of the light source module, and broadband light emitted by the light source module is received. The optical circulator inputs the broadband light to a cascading optical fiber sensor to form a reflection spectrum and then inputs the reflection spectrum to the 2 x 2 coupler.

The wavelength range of the light source module is 1528-1603 nm, the C wave band, and the output light intensity is 20.0 nW.

The cascade type optical fiber sensor is of an optical fiber Bragg grating-capillary glass tube-single mode optical fiber structure, namely, is composed of an optical fiber Bragg grating, a capillary glass tube and a single mode optical fiber, and is placed in a tubular heating furnace, wherein the tubular heating furnace comprises a temperature control switch module and a temperature display module and is used for heating the cascade type optical fiber sensor to improve the environment temperature; the temperature control switch module starts the heating function to a preset temperature, and the temperature display module displays real-time temperature.

The three interference peaks of the cascading optical fiber sensor in the wavelength range of 1530-1560 nm are in an external environment with the period of 10 ℃ and the change of the continuous application temperature of 30-220 ℃ is shown in a figure 2.

Specifically, as shown in fig. 3, the fiber bragg grating, the capillary glass tube and the single-mode fiber are all cylinders; the first cross section of the fiber Bragg grating is aligned with the first cross section of the capillary glass tube and then is subjected to discharge welding through a welding machine, the second cross section of the capillary glass tube is aligned with the first cross section of the single-mode fiber and then is subjected to discharge welding through the welding machine, a Fabry-Perot cavity is formed between the fiber Bragg grating and the single-mode fiber, and the fiber Bragg grating, the capillary glass tube and the single-mode fiber are coaxial, so that the fiber Bragg grating, the capillary glass tube and the single-mode fiber form a cascade type fiber sensor combining the fiber Bragg grating and the Fabry-Perot interferometer, broadband light output by the light source module is reflected in the fiber Bragg grating, interfered in the Fabry-Perot interferometer and reflected in the first cross section of the single-mode fiber, and cascade reflection spectrum of the fiber Bragg grating and the Fabry-Perot interferometer is generated. The fiber Bragg grating cladding diameter is 125 mu m, the fiber core diameter is 8 mu m, the center wavelength is 1555nm, the effective reflectivity is >90%, and the sidelobe suppression ratio is 15dB; the outer diameter of the capillary glass tube is 125 mu m, and the inner diameter of the capillary glass tube is 75 mu m; the single mode fiber is SMF-28e, and the cladding diameter is 125um.

The split ratio of the 2 x 2 coupler is 1:1, uniformly distributing the reflected light waves of the cascade optical fiber sensor into two paths, wherein one path of the reflected light waves is input into the spectrum analyzer to obtain the reflection spectrum of the cascade optical fiber sensor; the other path of the reflected spectrum deviation is input into the multichannel array waveguide grating, and the reflected spectrum deviation of the cascade type optical fiber sensor is converted into the transmitted light intensity variation in each channel; the cascade optical fiber sensor reflection spectrum is used for the data processing module as spectrum reference. The spectrum analyzer transmits the reflected spectrum wavelength data to the data processing module through the data line.

And N output ends of the multichannel array waveguide grating are respectively connected with the optical switch and the optical power meter.

In this embodiment, the multichannel arrayed waveguide grating is 40 channels, with a 125GHz specification, each channel can be used independently, the space between the central wavelengths of each channel is 0.8nm, and the full width at half maximum of each channel is 0.456nm; nine output channels are used in the multichannel arrayed waveguide grating, wherein first to eighth channel outputs are connected with first to eighth inputs of the optical switch, and ninth channel outputs are connected with first inputs of the optical power meter.

The optical switch is a multichannel micro-electromechanical system and is provided with eight input interfaces for controlling the light passing condition of each channel of the multichannel array waveguide grating, and the output of the optical switch is connected with the second input of the optical power meter.

The optical power meter is a dual-channel optical power meter, the detection range of transmitted light intensity is 0-69.00 dBm, the optical power meter is used for acquiring the transmitted light intensity of each channel of the multi-channel array waveguide grating, the transmitted light intensity is input to the data processing module for multi-parameter monitoring, and the data transmission interface is RS232.

And the data processing module performs data enhancement and expansion on the transmitted light intensity of each channel of the multichannel array waveguide grating acquired by the optical power meter and the wavelength data acquired from the spectrum analyzer, and demodulates the reflected spectrum signal of the cascade optical fiber sensor to obtain the peak value of each interference peak.

Specifically, the data processing module is configured with a generation countermeasure network and a deep neural network, the generation countermeasure network carries out data enhancement expansion on a data set of transmission light intensity information acquired from the multichannel array waveguide grating and reflection spectrum information acquired by the spectrum analyzer from the cascade type optical fiber sensor, and then the deep neural network demodulates each interference peak-to-peak wavelength of the cascade type optical fiber sensor in a specified wavelength range.

Wherein the generating countermeasure network includes a generator that generates a data set including transmitted light intensity information and spectral peak wavelength information, and a discriminator that discriminates the authenticity of the mixed real data set and the generated data set, as shown in fig. 4, and finally generates an enhanced data set closest to the real data set.

As shown in fig. 5, the deep neural network includes an input layer, three hidden layers and an output layer, where the input layer has nine neurons, each hidden layer has 14 neurons, the output layer has three neurons, and the three neurons are used to establish a complex nonlinear relationship between transmitted light intensity and wavelength shift under multiple parameters, and monitor peak wavelength shift of each interference peak of the cascaded optical fiber sensor in a certain wavelength range, and in this embodiment, errors of three peak wavelengths and actual peak wavelengths (from the reference quantity of the spectrum analyzer) of the cascaded optical fiber sensor output by the cascaded optical fiber sensor in the wavelength range of 1530-1560 nm are shown in fig. 6.

Correspondingly, the embodiment also discloses a multi-parameter monitoring method of the cascading optical fiber sensor, which specifically comprises the following steps:

step one, transmitting fixed-wavelength broadband light to an optical circulator through a light source module, outputting the fixed-wavelength broadband light to a cascading optical fiber sensor by the optical circulator, and outputting reflected light waves of the cascading optical fiber sensor to a 2 x 2 coupler by the optical circulator;

step two, the 2 x 2 coupler distributes the reflected light waves into two paths on average, one path of the reflected light waves is input to a spectrum analyzer to obtain the reflection spectrum of the cascade type optical fiber sensor, and the other path of the reflected light waves is input to each channel of the multi-channel array waveguide grating to convert the reflected light waves of the cascade type optical fiber sensor into the transmitted light intensity in each channel of the multi-channel array waveguide grating;

and thirdly, acquiring transmission light intensity information of each channel of the multichannel array waveguide grating by adopting an optical power meter, inputting the transmission light intensity information into a data processing module, and directly reading the transmission light intensity information by the data processing module by utilizing a trained end-to-end deep neural network and outputting corresponding interference peak-to-peak wavelength of the cascaded optical fiber sensor.

According to the cascade type optical Fiber sensor multi-parameter monitoring system, a multi-peak wavelength tracking and depth neural network algorithm is combined, the peak wavelength of each interference peak of a Fiber-Bragg-Grating and Fabry-Perot cascade sensor (a cascade type optical Fiber sensor combined with an optical Fiber Bragg grating and a Fabry-Perot interferometer) in a specified wavelength range is converted into transmission light intensity in each channel of an array waveguide grating, the transmission light intensity data is directly read by a trained end-to-end depth neural network model, and the peak wavelength of the corresponding interference peak is output, so that the system can achieve pm-level wavelength demodulation resolution without the aid of a spectrum analyzer in actual measurement application, the cost and complexity of the system are greatly reduced, stable and excellent demodulation performance are achieved, and good applicability is achieved; secondly, according to actual needs, the selected channels of the array waveguide grating can be adjusted to realize the change of the wavelength range monitored by the system; the demodulation system is stable, high in performance, cost-effective and suitable for various double-parameter monitoring systems.

Compared with the traditional wavelength tracking method, the method can reach the multi-wavelength demodulation resolution of pm level at the highest, and can realize high-precision multi-peak wavelength demodulation without using a spectrum analyzer in practical engineering application.

Specifically, the multi-channel array waveguide grating demultiplexes the reflected light wave of the Fiber-Bragg-Grating and Fabry-Perot cascade sensor into N channels below the Fiber-Bragg-Grating and Fabry-Perot cascade sensor, and converts the peak wavelength of each interference peak of the Fiber-Bragg-Grating and Fabry-Perot cascade sensor in a specified wavelength range into the transmitted light intensity of the Fiber-Bragg-Grating and Fabry-Perot cascade sensor in the N channels of the multi-channel array waveguide grating, wherein the transmitted light intensity is defined as the effective area of the overlapping part of the reflection interference spectrum of the Fiber-Bragg-Grating and Fabry-Perot cascade sensor and the reflection spectrum of the multi-channel array waveguide grating.

Specifically, a generating countermeasure network and a deep neural network are deployed in the data processing module, the generating countermeasure network is used for carrying out data enhancement on the transmitted light intensity obtained from the optical power meter and the data obtained from the spectrum analyzer, the deep neural network is used for inputting the transmitted light intensity under each channel of the multichannel array waveguide grating and outputting the peak wavelength of each interference peak of the cascade optical fiber sensor in a specified wavelength range.

It can be understood that the generated countermeasure network and the deep neural network have excellent data enhancement and demodulation performance, have good generalization capability, and have the performance of easy deployment and expansion of application scenes.

In summary, the invention provides the preparation of the complete cascade type optical fiber sensor and the simple manufacturing of the cascade type optical fiber sensor with low preparation cost, overcomes the manufacturing difficulty of the cascade type optical fiber sensor, relies on the transmission light intensity information from the cascade type optical fiber sensor obtained from the multichannel array waveguide grating, enhances the diversity of a data set to a great extent by combining with the generation of the countermeasure network, inputs the data set into the deep neural network, can realize the demodulation spectral information with high efficiency, high precision and low cost, does not need to rely on an expensive and complicated spectrum analyzer and an excessively complex algorithm, and simultaneously generates the countermeasure network and the deep neural network, so that the cascade type optical fiber sensor multi-parameter monitoring system can be integrated, miniaturized and easy to deploy and is used for multi-parameter monitoring of the cascade type optical fiber sensor under a more severe environment.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the foregoing detailed description of the invention has been provided, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing examples, and that certain features may be substituted for those illustrated and described herein. Modifications, equivalents, and alternatives falling within the spirit and principles of the invention are intended to be included within the scope of the invention.

Claims (10)

1. A cascading fiber optic sensor multi-parameter monitoring system comprising: light source module, optical circulator, cascade optical fiber sensor, 2 couplers, multichannel array waveguide grating, optical switch, optical power meter, tubular heating furnace, data processing module, its characterized in that:

the optical circulator comprises an input end, an output end and an output end, wherein the input end and the output end are connected to the cascading optical fiber sensor, the output end is connected to the input end of the 2 x 2 coupler, the input end is connected with the output end of the light source module, the optical circulator receives broadband light emitted by the light source module and inputs the broadband light to the cascading optical fiber sensor to form reflected light, and the reflected light is input to the 2 x 2 coupler;

an output end of the 2 x 2 coupler is connected with an input end of a multi-channel array waveguide grating, and the multi-channel array waveguide grating converts the reflected light wave offset into transmission light intensity variation in each channel;

the optical power meter is a dual-channel optical power meter, N output end channels of the multi-channel array waveguide grating are respectively connected with the input end of the optical switch and the first input end of the optical power meter, the optical switch controls the light passing condition of each channel of the multi-channel array waveguide grating, and the output end of the optical switch is connected with the second input end of the optical power meter;

the optical power meter output is connected to the data processing module, and the acquired transmission light intensity in each channel of the multichannel array waveguide grating is input to the data processing module for multi-parameter monitoring;

the cascade optical fiber sensor is placed in the tubular heating furnace.

2. A cascading optical fiber sensor multi-parameter monitoring system as set forth in claim 1, wherein: the optical spectrum analyzer is connected with the other output end of the 2 x 2 coupler, reflected light waves are input into the optical spectrum analyzer, the reflection spectrum of the cascading optical fiber sensor is obtained, and the optical spectrum analyzer transmits the peak wavelength data of the reflection spectrum to the data processing module through a data line to serve as spectrum reference.

3. A cascading optical fiber sensor multi-parameter monitoring system as set forth in claim 2, wherein: the split ratio of the 2 x 2 coupler is 1: and 1, equally distributing the reflected light waves of the cascade optical fiber sensor into two paths.

4. A cascading optical fiber sensor multi-parameter monitoring system as set forth in claim 2, wherein: the data processing module is provided with a generation countermeasure network and a deep neural network, the generation countermeasure network carries out data enhancement expansion on a data set of transmission light intensity information acquired from the multichannel array waveguide grating and reflection spectrum information of the cascade type optical fiber sensor acquired by the spectrum analyzer, and then the data set is demodulated by the deep neural network to acquire peak values of interference peaks of reflection spectrum signals of the cascade type optical fiber sensor.

5. A cascading optical fiber sensor multi-parameter monitoring system as defined in claim 4, wherein: the generating countermeasure network comprises a generator and a discriminator, wherein the generator generates a data set containing transmitted light intensity information and reflection spectrum peak wavelength information, the discriminator discriminates the authenticity of the mixed real data set and the generated data set, and finally generates an enhanced data set closest to the real data set.

6. A cascading optical fiber sensor multi-parameter monitoring system as defined in claim 4, wherein: the deep neural network comprises an input layer, three hidden layers and an output layer, wherein the input layer is provided with nine neurons, each hidden layer is provided with 14 neurons, and the output layer is provided with three neurons.

7. A cascading optical fiber sensor multi-parameter monitoring system as set forth in claim 1, wherein: the cascade type optical fiber sensor is a cascade type optical fiber sensor combining an optical fiber Bragg grating and a Fabry-Perot interferometer, and is composed of the optical fiber Bragg grating, a capillary glass tube and a single-mode optical fiber, wherein the optical fiber Bragg grating, the capillary glass tube and the single-mode optical fiber are all cylindrical, the first cross section of the optical fiber Bragg grating is aligned with the first cross section of the capillary glass tube and then is subjected to discharge welding through a welding machine, the second cross section of the capillary glass tube is aligned with the first cross section of the single-mode optical fiber and then is subjected to discharge welding through the welding machine, and then a Fabry-Perot cavity is formed between the optical fiber Bragg grating and the single-mode optical fiber, and the optical fiber Bragg grating, the capillary glass tube and the single-mode optical fiber are coaxial.

8. A cascading optical fiber sensor multi-parameter monitoring system as set forth in claim 7, wherein: the cladding diameter of the fiber Bragg grating is 125 mu m, the fiber core diameter is 8 mu m, the central wavelength is 1555nm, the effective reflectivity is more than 90%, and the sidelobe suppression ratio is 15dB; the outer diameter of the capillary glass tube is 125 mu m, and the inner diameter of the capillary glass tube is 75 mu m; the single mode fiber is SMF-28e, and the cladding diameter is 125um.

9. A cascading optical fiber sensor multi-parameter monitoring system as set forth in claim 1, wherein: the tubular heating furnace comprises a temperature control switch module and a temperature display module, wherein the temperature control switch module starts a heating function to enable the temperature in the furnace to reach a preset temperature, and the temperature display module displays real-time temperature.

10. A multi-parameter monitoring method employing a cascade type optical fiber sensor multi-parameter monitoring system as claimed in any one of claims 1 to 9, comprising:

step one, transmitting fixed-wavelength broadband light to an optical circulator through a light source module, outputting the fixed-wavelength broadband light to a cascading optical fiber sensor by the optical circulator, and outputting reflected light waves of the cascading optical fiber sensor to a 2 x 2 coupler by the optical circulator;

step two, the 2 x 2 coupler distributes the reflected light waves into two paths on average, one path of the reflected light waves is input to a spectrum analyzer to obtain the reflection spectrum of the cascade type optical fiber sensor, and the other path of the reflected light waves is input to each channel of the multi-channel array waveguide grating to convert the reflected light waves of the cascade type optical fiber sensor into the transmitted light intensity in each channel of the multi-channel array waveguide grating;

and thirdly, acquiring transmission light intensity information of each channel of the multichannel array waveguide grating by adopting an optical power meter, inputting the transmission light intensity information into a data processing module, and directly reading the transmission light intensity information by the data processing module by utilizing a trained end-to-end deep neural network and outputting corresponding interference peak-to-peak wavelength of the cascaded optical fiber sensor.