CN208736433U - A kind of multi-functional distributing optical fiber sensing teaching equipment - Google Patents
A kind of multi-functional distributing optical fiber sensing teaching equipment Download PDFInfo
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Abstract
The utility model relates to a kind of multi-functional distributing optical fiber sensing teaching equipments, including power module, light source module, the first detector module, the second detector module, data collecting card module, circulator module, polarization beam apparatus module, wavelength division multiplexer module.The utility model has compressed manufacturing cost by multiplexing part module;By being packaged consolidation process to all modules, allows intermodule to realize assembling by connecting line and split, reduce system bulk, improve the flexibility of system, and impart the characteristics of it can show internal structure and good scalability;By appropriately combined each module, three kinds of optical time domain reflection, polarized light time domain reflection and Raman optical time domain reflection distributed sensing functions may be implemented.
Description
Technical Field
The utility model belongs to the technical field of distributed optical fiber sensing, in particular to distributed sensing teaching and research equipment based on Optical Time Domain Reflection (OTDR), polarized light time domain reflection (POTDR), Raman Optical Time Domain Reflection (ROTDR) technique.
Background
When light waves enter an inhomogeneous medium, the inhomogeneity of the medium causes fluctuations in density and refractive index, which in turn causes scattering in all directions, called rayleigh scattering. In 1977, Barnoski et al proposed an Optical Time Domain Reflectometer (OTDR), which injects probe pulse light into the front end of an Optical fiber, measures the loss of each position along the Optical fiber by using the change of the intensity of backward rayleigh scattered light of the pulse light, and obtains the position information of the loss through the Time difference between the injection of the probe pulse light and the reception of the backward rayleigh scattered light, thereby obtaining the magnitude of the loss and the position information of the loss, and realizing distributed Optical fiber sensing. Since then, OTDRs have been widely used in applications such as measurement and positioning of loss and bending in optical fibers.
In 1928, raman scattering experimental phenomena were reported in Nature journal by indian scientists, and then raman spectroscopy developed vigorously, especially after laser light appeared, raman spectroscopy gradually developed into a conventional spectral measurement means, and was gradually applied to the fields of parameter measurement, spectral analysis, optical fiber sensing and the like. The distributed optical fiber Raman temperature measurement system is used for measuring the temperature based on the temperature effect of Raman scattering light, and after incident light enters an optical fiber, photons and molecules react due to the nonuniformity of the refractive index of the fiber core of the optical fiber to generate backward Raman scattering light. The intensity of the backward Raman scattering light is influenced by the ambient temperature of the backward Raman scattering light, so that the temperature field information can be acquired by detecting the intensity change of the power of the Raman scattering light through the photoelectric detector.
Polarization is one of the important physical properties possessed by light waves. When light waves are transmitted in the optical fiber, the polarization state of the light waves is sensitive to various conditions of deformation, vibration, electromagnetic field and the like of the optical fiber, and the detection of corresponding changes along the optical fiber can be realized by detecting the changes of the polarization state of the light waves. The optical fiber sensing technology based on polarization effect is mainly a Polarized Optical Time Domain Reflectometer (POTDR), which was first proposed by Rogers in 1980 for measuring the electric field, pressure, temperature, etc. to which the optical fiber is subjected. Subsequently, the POTDR is more used to measure parameters related to optical communication, such as Polarization Mode Dispersion (PMD) and birefringence, in the optical fiber, and plays an important role in performance evaluation of the optical fiber communication line, PMD compensation, improvement of communication rate, and the like. In recent years, because of the characteristic that the polarization state is sensitive to the external parameters of the optical fiber, the research of the POTDR in the measurement of the external parameters of the optical fiber is also increasing.
In recent decades, the distributed optical fiber sensing technology has been widely applied to monitoring the status of various environments such as roads, bridges, tunnels, perimeters, power and the like due to its advantages of no electricity, intrinsic safety, long sensing distance, capability of continuously monitoring information at any position along an optical fiber and the like. Meanwhile, with the continuous and deep research on the distributed optical fiber sensing system in domestic colleges and universities and scientific research institutes, more and more scientific research achievements need to be converted into actual products. However, the distributed optical fiber sensing equipment in the current market is based on a single sensing principle, is often expensive and large in size, and the whole system is a black box, so that the specific system structure in the whole system cannot be seen. This undoubtedly hinders the development of experimental courses for distributed fiber sensing in colleges and universities, thereby hindering the popularization and application of this technology.
To present distributed optical fiber sensing equipment that has now all be based on single sensing principle, and expensive, and the volume is great, and entire system is a black box, can't see inside concrete system structure scheduling problem, the utility model provides an integrated distributed optical fiber sensing teaching and research equipment of three kinds of functions of OTDR, POTDR and ROTDR, with low costs, small, entire system has been cut apart into a plurality of modules, is convenient for observe and the dismouting, has very strong practical value.
SUMMERY OF THE UTILITY MODEL
In order to solve the problem, the utility model provides a multi-functional distributed optical fiber sensing teaching equipment, include: the device comprises a power supply module, a light source module, a first detector module, a second detector module, a data acquisition card module, a circulator module, a polarization beam splitter module and a wavelength division multiplexer module.
When using the OTDR function of the utility model: the power supply module is respectively connected with the light source module, the first detector module and the data acquisition card module and supplies power to the latter three modules; the light source module is connected with the data acquisition card module, a generated pulse clock signal is transmitted to the data acquisition card module, the light source module is further sequentially connected with the circulator module and the optical fiber to be detected, pulse laser generated by the light source module enters the optical fiber to be detected through the circulator module, the circulator module is further connected with the first detector module, the first detector module is connected with the data acquisition card module, Rayleigh scattered light generated by the optical fiber to be detected and transmitted in the back direction enters the first detector module through the circulator module, the first detector module converts a received optical signal into an electric signal and transmits the electric signal to the data acquisition card module, and the data acquisition card module converts the received signal into a digital signal and outputs the digital signal to a computer.
When the polarized light time domain reflection function is used, the power supply module is respectively connected with the light source module, the first detector module and the data acquisition card module to supply power to the latter three modules; the light source module is connected with the data acquisition card module, a generated pulse clock signal is transmitted to the data acquisition card module, the light source module is further sequentially connected with the circulator module and the optical fiber to be detected, pulse laser generated by the light source module enters the optical fiber to be detected through the circulator module, the circulator module is further sequentially connected with the polarization beam splitter module and the first detector module, Rayleigh scattered light generated by the optical fiber to be detected enters the polarization beam splitter module through the circulator module, the polarization beam splitter module divides incident light into two beams of linearly polarized light with orthogonal polarization directions and transmits any one of the two beams to the first detector module, the first detector module converts a received optical signal into an electric signal and transmits the electric signal to the data acquisition card module, and the data acquisition card module converts the received signal into a digital signal and outputs the digital signal to a computer.
When the Raman optical time domain reflection function is used, the power supply module is respectively connected with the light source module, the first detector module, the second detector module and the data acquisition card module to supply power to the latter four modules; the light source module is connected with the data acquisition card module, a generated pulse clock signal is transmitted to the data acquisition card module, the light source module is also sequentially connected with the wavelength division multiplexer module and the optical fiber to be detected, pulse laser generated by the light source module enters the optical fiber to be detected through the wavelength division multiplexer module, the wavelength division multiplexer module is respectively connected with the first detector module and the second detector module, Stokes light in Raman scattered light generated in the optical fiber to be detected and transmitted in a back direction enters the first detector module through the wavelength division multiplexer module, generated anti-Stokes light enters the second detector module through the wavelength division multiplexer module, the two detector modules convert received optical signals into electric signals and transmit the electric signals to the data acquisition card module, and the data acquisition card module converts the received optical signals into digital signals and outputs the digital signals to a computer.
The invention has the beneficial effects that: the utility model discloses utilize OTDR, ROTDR, three kinds of distributed sensing schemes of POTDR to light source, detector, this characteristics of the requirement unanimity basically of data acquisition card, entire system has only adopted a light source, and a data acquisition card and two detectors have reduced manufacturing cost by a wide margin.
The utility model discloses all modules to constituting entire system have all carried out the encapsulation and have consolidated the processing for can realize equipment and split through the connecting wire between the module, improve the flexibility of system, give its characteristics that can demonstrate inner structure.
The utility model discloses separately encapsulate each module, solved the device and generated heat the problem of concentrating to need not to use active heat abstractor such as fan, effectively reduced entire system's volume.
The utility model discloses decompose entire system into a plurality of modules, consequently can only change the extension and the update of realization system function under the condition of specific module, provide very big facility for developer and user.
Drawings
Fig. 1 is a schematic diagram of the system assembly structure when the OTDR function is used in the present invention.
Fig. 2 is a schematic diagram of the present invention using OTDR function.
Fig. 3 is a schematic diagram of the system assembly structure when the POTDR function is used in the present invention.
Fig. 4 is a schematic diagram of the POTDR system using the POTDR function of the present invention.
Fig. 5 is a schematic diagram of the system assembly structure when the ROTDR function is used in the present invention.
Fig. 6 is a schematic diagram of the present invention using the ROTDR function.
Detailed Description
The invention is further described with reference to the following detailed description and accompanying drawings.
As shown in fig. 1 and 2, a system structure of a multifunctional distributed optical fiber sensing teaching device when implementing an OTDR function includes: multi-functional distributed optical fiber sensing teaching equipment 1, the optic fibre 2 that awaits measuring, computer 3, wherein, multi-functional distributed optical fiber sensing teaching equipment 1 includes again: the device comprises a power module 4, a light source module 5, a circulator module 6, a first detector module 7 and a data acquisition card module 8; the 4_1 port of the power module 4 is connected with the 5_1 port of the light source module 5, the 4_2 port of the power module 4 is connected with the 8_1 port of the data acquisition card 8, the 4_3 port of the power module 4 is connected with the 7_1 port of the first detector module 7, the 5_2 port of the light source module 5 is connected with the 6_1 port of the circulator module 6, the 5_3 port of the light source module 5 is connected with the 8_2 port of the data acquisition card module 8, the 6_2 port of the circulator module 6 is connected with the optical fiber 2 to be detected, the 6_3 port of the circulator module 6 is connected with the 7_2 port of the first detector module 7, the 7_3 port of the first detector module 7 is connected with the 8_3 port of the data acquisition card module 8, and the 8_4 port of the data acquisition card module 8 is connected with the computer 3.
The utility model discloses realize the working method of OTDR function and do: after the power module 4 is turned on, the pulse laser generated by the light source module 5 enters the optical fiber 2 to be detected through the circulator module 6, along with the transmission of incident light, the rayleigh scattered light generated in the optical fiber 2 to be detected and transmitted back enters the first detector module 7 through the circulator module 6, the first detector module 7 converts the received optical signal into an electrical signal and transmits the electrical signal to the data acquisition card module 8, meanwhile, the pulse clock signal of the light source module 5 is also transmitted to the data acquisition card module 8, and the data acquisition card module 8 converts the received signal into a digital signal and transmits the digital signal to the computer 3.
As shown in fig. 3 and 4, the system structure of the multifunctional distributed optical fiber sensing teaching device when implementing the POTDR function includes: multi-functional distributed optical fiber sensing teaching equipment 1, the optic fibre 2 that awaits measuring, computer 3, wherein, multi-functional distributed optical fiber sensing teaching equipment 1 includes again: the device comprises a power module 4, a light source module 5, a circulator module 6, a polarization beam splitter module 7, a first detector module 8 and a data acquisition card module 9; the 4_1 port of the power module 4 is connected with the 5_1 port of the light source module 5, the 4_2 port of the power module 4 is connected with the 9_1 port of the data acquisition card 9, the 4_3 port of the power module 4 is connected with the 8_1 port of the first detector module 8, the 5_2 port of the light source module 5 is connected with the 6_1 port of the circulator module 6, the 5_3 port of the light source module 5 is connected with the 9_2 port of the data acquisition card module 9, the 6_2 port of the circulator module 6 is connected with the optical fiber 2 to be detected, the 6_3 port of the circulator module 6 is connected with the 7_1 port of the polarization beam splitter module 7, the 7_2 port of the polarization beam splitter module 7 is connected with the 8_2 port of the first detector module 8, the 8_3 port of the first detector module 8 is connected with the 9_3 port of the data acquisition card module 9, and the 9_4 port of the data acquisition card module 9 is connected with the computer 3.
The utility model discloses realize the working method of POTDR function and do: after the power module 4 is turned on, the pulse laser generated by the light source module 5 enters the optical fiber 2 to be measured through the circulator module 6, along with the transmission of the incident light, the rayleigh scattered light generated in the optical fiber 2 to be measured and transmitted in the opposite direction enters the polarization beam splitter module 7 through the circulator module 6, the polarization beam splitter module 7 divides the incident light into two beams of linearly polarized light with orthogonal polarization directions, one beam of the polarized light is transmitted to the first detector module 8, the first detector module 8 converts the received optical signal into an electrical signal and transmits the electrical signal to the data acquisition card module 9, meanwhile, the pulse clock signal of the light source module 5 is also transmitted to the data acquisition card module 9, and the data acquisition card module 9 converts the received signal into a digital signal and transmits the digital signal to the computer 3.
As shown in fig. 5 and 6, the system structure of the multifunctional distributed optical fiber sensing teaching device when implementing the ROTDR function includes: multi-functional distributed optical fiber sensing teaching equipment 1, the optic fibre 2 that awaits measuring, computer 3, wherein, multi-functional distributed optical fiber sensing teaching equipment 1 includes again: the system comprises a power module 4, a light source module 5, a wavelength division multiplexer module 6, a first detector module 7, a second detector module 8 and a data acquisition card module 9; the port 4_1 of the power module 4 is connected with the port 5_1 of the light source module 5, the port 4_2 of the power module 4 is connected with the port 9_1 of the data acquisition card 9, the port 4_3 of the power module 4 is connected with the port 8_1 of the second detector module 8, the port 4_4 of the power module 4 is connected with the port 7_1 of the first detector module 7, the port 5_2 of the light source module 5 is connected with the port 6_1 of the wavelength division multiplexer module 6, the port 5_3 of the light source module 5 is connected with the port 9_2 of the data acquisition card module 9, the port 6_2 of the wavelength division multiplexer module 6 is connected with the optical fiber 2 to be tested, the port 6_3 of the wavelength division multiplexer module 6 is connected with the port 7_2 of the first detector module 7, the port 6_4 of the wavelength division multiplexer module 6 is connected with the port 8_2 of the second detector module 8, the 7_3 port of the first detector module 7 is connected with the 9_3 port of the data acquisition card module 9, the 8_3 port of the second detector module 8 is connected with the 9_4 port of the data acquisition card module 9, and the 9_5 port of the data acquisition card module 9 is connected with the computer 3.
The utility model discloses realize that the working method of ROTDR function does: after the power module 4 is turned on, pulse laser generated by the light source module 5 enters the optical fiber 2 to be detected through the wavelength division multiplexer module 6, stokes light in backward transmitted raman scattering light generated in the optical fiber 2 to be detected enters the first detector module 7 through the wavelength division multiplexer module 6 along with transmission of incident light, anti-stokes light in backward transmitted raman scattering light generated in the optical fiber 2 to be detected enters the second detector module 8 through the wavelength division multiplexer module 6, the first detector module 7 and the second detector module 8 convert received optical signals into electrical signals and transmit the electrical signals to the data acquisition card module 9, meanwhile, pulse clock signals of the light source module 5 are also transmitted to the data acquisition card module 9, and the data acquisition card module 9 converts the received signals into digital signals and transmits the digital signals to the computer 3.
In one embodiment of the present invention, the light source module is a DTS pulse light source module manufactured by shanghai konit corporation, the model is VFLS-155-M-DTS, the central wavelength is 1550nm, the line width is less than 0.2nm, and the pulse width and the output power are adjustable; the data acquisition card module adopts a data acquisition card with the model number of USB9825B-20, which is produced by Beijing Xinghuo Huachu corporation, the resolution ratio is 12 bits, the channel is double, the sampling rate is 20MS/s, and the signal-to-noise ratio is 70 dB; the first detector module and the second detector module both use InGaAs-APD detectors produced by Shenzhen Feibo Source company, the model is IAM-6020, and the detection optical power is-60 dBm; the circulator module uses an optical circulator produced by Sichuan-level high-tech, and the isolation degree is between 40 and 50 dB.
What has been described above and shown in the drawings is merely a preferred embodiment of the invention. Without departing from the principles of the present invention, one of ordinary skill in the art can also make several modifications and improvements, which should also be considered as falling within the scope of the present invention.
Claims (5)
1. A multifunctional distributed optical fiber sensing teaching device is characterized by comprising: the device comprises a power supply module, a light source module, a first detector module, a second detector module, a data acquisition card module, a circulator module, a polarization beam splitter module and a wavelength division multiplexer module; wherein,
when the optical time domain reflection-based function is used, the power supply module is respectively connected with the light source module, the first detector module and the data acquisition card module to supply power to the latter three modules; the light source module is connected with the data acquisition card module, a generated pulse clock signal is transmitted to the data acquisition card module, the light source module is also sequentially connected with the circulator module and the optical fiber to be detected, pulse laser generated by the light source module enters the optical fiber to be detected through the circulator module, the circulator module is also connected with the first detector module, the first detector module is connected with the data acquisition card module, Rayleigh scattered light generated by the optical fiber to be detected and transmitted in the back direction enters the first detector module through the circulator module, the first detector module converts a received optical signal into an electric signal and transmits the electric signal to the data acquisition card module, and the data acquisition card module converts the received signal into a digital signal and outputs the digital signal to a computer;
when the polarized light time domain reflection function is used, the power supply module is respectively connected with the light source module, the first detector module and the data acquisition card module to supply power to the latter three modules; the light source module is connected with the data acquisition card module, a generated pulse clock signal is transmitted to the data acquisition card module, the light source module is also sequentially connected with the circulator module and the optical fiber to be detected, the generated pulse laser enters the optical fiber to be detected through the circulator module, the circulator module is also sequentially connected with the polarization beam splitter module and the first detector module, Rayleigh scattered light generated by the optical fiber to be detected enters the polarization beam splitter module through the circulator module, the polarization beam splitter module divides incident light into two beams of linearly polarized light with orthogonal polarization directions and transmits any one of the two beams to the first detector module, the first detector module converts a received optical signal into an electric signal and transmits the electric signal to the data acquisition card module, and the data acquisition card module converts the received signal into a digital signal and outputs the digital signal to a computer;
when the Raman optical time domain reflection function is used, the power supply module is respectively connected with the light source module, the first detector module, the second detector module and the data acquisition card module to supply power to the latter four modules; the light source module is connected with the data acquisition card module, a generated pulse clock signal is transmitted to the data acquisition card module, the light source module is also sequentially connected with the wavelength division multiplexer module and the optical fiber to be detected, pulse laser generated by the light source module enters the optical fiber to be detected through the wavelength division multiplexer module, the wavelength division multiplexer module is respectively connected with the first detector module and the second detector module, Stokes light in Raman scattered light generated in the optical fiber to be detected and transmitted in a back direction enters the first detector module through the wavelength division multiplexer module, generated anti-Stokes light enters the second detector module through the wavelength division multiplexer module, the two detector modules convert received optical signals into electric signals and transmit the electric signals to the data acquisition card module, and the data acquisition card module converts the received optical signals into digital signals and outputs the digital signals to a computer.
2. The multifunctional distributed optical fiber sensing teaching device according to claim 1, wherein the power module, the light source module, the first detector module, the second detector module, the data acquisition card module, the circulator module, the polarization beam splitter module, and the wavelength division multiplexer module are independently packaged by using a protective housing.
3. The multifunctional distributed optical fiber sensing teaching device of claim 1, wherein said light source module uses a DTS pulsed light source module with model number VFLS-155-M-DTS.
4. The multifunctional distributed optical fiber sensing teaching device according to claim 1, wherein the data acquisition card module uses a data acquisition card with a model number of USB 9825B-20.
5. The multifunctional distributed optical fiber sensing teaching device according to claim 1, wherein the first detector module and the second detector module both use a detector with model number IAM-6020.
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Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
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CN111238549A (en) * | 2020-01-14 | 2020-06-05 | 华东师范大学 | All-fiber interference method and device for inhibiting back scattering by utilizing polarization coding |
CN112697180A (en) * | 2020-11-27 | 2021-04-23 | 南京大学 | Fusion type distributed optical fiber sensing system and method for simultaneously measuring temperature and vibration |
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Cited By (3)
Publication number | Priority date | Publication date | Assignee | Title |
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CN111238549A (en) * | 2020-01-14 | 2020-06-05 | 华东师范大学 | All-fiber interference method and device for inhibiting back scattering by utilizing polarization coding |
CN111238549B (en) * | 2020-01-14 | 2021-07-27 | 华东师范大学 | All-fiber interference method for inhibiting back scattering by utilizing polarization coding |
CN112697180A (en) * | 2020-11-27 | 2021-04-23 | 南京大学 | Fusion type distributed optical fiber sensing system and method for simultaneously measuring temperature and vibration |
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