A measuring device and method for quickly measuring an optical fiber sensor array

Abstract

The present invention relates to the field of fiber optic sensor array measurement, and particularly to a measurement device and method for rapidly measuring a fiber optic sensor array, characterized in that: it includes a tunable wavelength light source (1), the tunable wavelength light source (1) is connected to a 1*M optical switch, the fiber optic sensor to be measured (3) is connected to the other end of the 1*M optical switch, the fiber optic sensor to be measured (3) is simultaneously connected to a plurality of 1*N optical switches, the plurality of 1*N optical switches are respectively connected to a plurality of PD photoelectric conversions, and the plurality of PD photoelectric conversions are simultaneously connected to an oscilloscope and a display and control terminal computer (12), where M is greater than or equal to N. Instead of using the method of unplugging and plugging each time to replace the fiber optic sensor to be measured with a standard attenuator in the optical path and then measuring the light intensity after passing through the standard attenuator, the present invention automatically switches the standard attenuator with an optical switch to directly measure the light intensity of the light source, avoiding the influence of manual unplugging and plugging, and bringing better repeatability and stability.

Description

Technical Field

[0001] The present invention relates to the field of fiber optic sensor array measurement, and particularly to a measurement device and method for quickly measuring a fiber optic sensor array. Background Art

[0002] Fiber optic sensing technology is a new technology formed along with the development of optical fibers and fiber optic communication technology. The sensing sensitivity of fiber optic hydrophones is many times higher than that of traditional piezoelectric hydrophones, and it can work normally in many special environments such as high voltage, high noise, high temperature, and strong corrosion. It can also cooperate with fiber optic remote sensing and telemetry technologies to form fiber optic remote sensing systems and fiber optic telemetry systems. Therefore, fiber optic sensing technology can be widely applied in many fields such as aerospace, nuclear industry, bridge tunnels, construction, oil extraction, power transmission, medical treatment, and scientific research.

[0003] A fiber optic hydrophone is a specific application technology of fiber optic sensing technology. The fiber optic hydrophone changes the refractive index or length of the fiber core through the stress action of underwater sound waves on the fiber, thereby causing a change in the optical path of the light beam propagating in the fiber and resulting in a phase change. Interference measurement technology can be used to detect the phase change and obtain information about underwater sound. It uses the phase interference of light as a detection means, with extremely high detection sensitivity and a relatively wide response bandwidth; it uses optical fibers as the information sensing and transmission medium; and the information carried by light is neither subject to electromagnetic interference nor at risk of leakage.

[0004] Testing the loss of a fiber optic sensor array is an important means for detecting the performance and environmental adaptability of fiber optic sensors. The IEC61300-3-4:2012 standard stipulates several loss test methods for fiber optic interconnection devices, but these schemes cannot measure the losses of multiple spatial divisions. Since a light power meter is used for measurement, it cannot measure the waveforms of multiple pulses that arrive at the detector successively in time within the same optical path. For fiber optic sensor arrays with multiple spatial, wavelength, and time divisions, the testing takes a long time. Due to the lack of devices such as optical switches in the prior art, the loss of only one optical path can be tested each time, so the testing of multi-channel samples takes a long time. When changing different optical paths, the insertion and removal of flanges are required, resulting in poor repeatability and stability, and being easily affected by human errors. Therefore, it is necessary to invent a device and method for quickly testing the loss of a fiber optic sensor array in a short time. Summary of the Invention

[0005] In order to solve the problem of quickly measuring the optical path losses of multiple sensors on multiple optical paths of a fiber optic sensor array, the present invention uses an optical switch to quickly measure the optical path losses of multiple sensors on multiple optical paths of a fiber optic sensor array, and provides a device and method for quickly testing the loss of a fiber optic sensor array.

[0006] The specific technical solution thereof is as follows:

[0007] A measuring device for quickly measuring a fiber optic sensor array, comprising a tunable wavelength light source 1, the tunable wavelength light source 1 is connected to a 1*M optical switch, and the fiber optic sensor 3 to be measured is connected to the other end of the 1*M optical switch. The fiber optic sensor 3 to be measured is simultaneously connected to a plurality of 1*N optical switches, and the plurality of 1*N optical switches are respectively connected to a plurality of PD photoelectric conversions. The plurality of PD photoelectric conversions are simultaneously connected to an oscilloscope and a display control terminal computer 12, where M is greater than or equal to N.

[0008] Further, the wavelength range of the light emitted by the tunable wavelength light source 1 is 1537.40 nm to 1561.42 nm.

[0009] Further, M is 16 and N is 4.

[0010] Further, the material of the PD photoelectric conversion is InGaAs semiconductor, and its function is to convert an input optical signal in a certain wavelength range into a current signal linearly related to its power.

[0011] A measuring method using the above-mentioned measuring device for quickly measuring a fiber optic sensor array, comprising the following steps:

[0012] Step 1: The tunable wavelength light source 1 emits an optical pulse signal and exports it with an optical jumper.

[0013] Step 2: After the signal of the tunable wavelength light source 1 is exported by the optical jumper, it enters the fiber optic sensor 3 to be measured through a 1*M optical switch. The 1*M optical switch outputs the signal of the tunable wavelength light source 1 to M flanges respectively through time-division multiplexing.

[0014] Step 3: Divide the M outgoing optical flanges into N groups and each group enters a 1*N optical switch, and then enters a plurality of PD photoelectric conversions in sequence after entering the 1*N optical switch.

[0015] Step 4: The electrical signal converted from the optical signal by the PD photoelectric conversion is transferred to the BNC interface of the oscilloscope and the display control terminal computer 12 through the SMA interface for sampling. The data collected by a total of N channels of the oscilloscope and the display control terminal computer 12 are transmitted into the computer through a network cable or a serial port. Each channel can contain M time-division pulses, and the optical path loss of the fiber optic sensor 3 to be measured is obtained by processing according to Appendix B in HX 13023-2020. According to the time-division multiplexing method, the channel data of space-division and time-division can be all processed sequentially.

[0016] Step 5: Change the frequency or wavelength of the light emitted by the variable tunable wavelength light source 1 to measure the optical path loss of multiple wavelength divisions of the fiber optic sensor 3 to be measured.

[0017] The beneficial effects brought by the present invention:

[0018] 1. The present invention can quickly measure the losses of multiple optical paths through time-division, wavelength-division, and space-division structures.

[0019] 2. Instead of using the method of plugging and unplugging each time to replace the fiber optic sensor under test with a standard attenuator in the optical path and then measuring the light intensity after passing through the standard attenuator, the present invention automatically switches the standard attenuator with an optical switch to directly measure the light intensity of the light source, avoiding the influence of manual plugging and unplugging and bringing better repeatability and stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of a test device disclosed by the present invention

[0021] DESCRIPTION OF THE REFERENCE NUMERALS:

[0022] 1. Tunable wavelength light source; 2. 1*16 optical switch; 3. Fiber optic sensor under test; 4. First 1*4 optical switch; 5. Second 1*4 optical switch; 6. Third 1*4 optical switch; 7. Fourth 1*4 optical switch; 8. First PD photoelectric conversion; 9. Second PD photoelectric conversion; 10. Third PD photoelectric conversion; 11. Fourth PD photoelectric conversion; 12. Oscilloscope and display control terminal computer DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the embodiments described herein are only for the purpose of illustrating and explaining the present invention and are not intended to limit the present invention.

[0024] Time-division multiplexing, wavelength-division multiplexing, and space-division multiplexing of a fiber optic hydrophone array refer to the working modes in which array elements or sub-arrays obtain laser interrogation from the array bus in the array and transmit the detected underwater acoustic signals to the array bus.

[0025] Time-division multiplexing means that array elements or sub-arrays share the array bus and work serially and cyclically one by one at different times;

[0026] Wavelength-division multiplexing means that array elements or sub-arrays share the array bus and work in parallel at different laser working wavelengths;

[0027] Space-division multiplexing means that array elements or sub-arrays share the array bus and work in parallel at different fiber optic transmission lines.

[0028] See Figure 1, which is a test device for an optical fiber hydrophone array according to the present invention. It includes a tunable wavelength light source 1, the tunable wavelength light source 1 is connected to a 1*16 optical switch 2, and the fiber optic sensor 3 to be tested is connected to the other end of the 1*16 optical switch 2. The fiber optic sensor 3 to be tested is simultaneously connected to 4 1*4 optical switches, and the 4 1*4 optical switches are respectively connected to 4 PD photoelectric conversions, and the 4 PD photoelectric conversions are simultaneously connected to an oscilloscope and a display and control terminal computer 12. Among them, in the above device, the number of optical splitting paths and the number of optical switches of the 1*16 optical switch 2 and the 1*4 optical switch can be changed according to the requirements of the fiber optic sensor 3 to be tested. The number of optical splitting paths 16 in the above 1*16 optical switch 2 is set as M, and the number of optical splitting paths in the 1*4 optical switch is set as N, where M is greater than or equal to N.

[0029] Referring to Figure 1 the device shown, the working process of the test device disclosed by the present invention is as follows: The fiber optic sensor 3 to be tested is connected to the test device. The tunable wavelength light source 1 emits a laser pulse signal of one of the 16 wavelength channels with wavelengths from C20 to C50 (the specific wavelength values should refer to the international standard ITU G.654.1 document. The C20 to C50 channels generally refer to wavelengths from 1537.40 nm to 1561.42 nm), and the specific channel can be controlled by the oscilloscope and the display and control terminal computer 12; it enters the space division channel or the standard attenuator of the fiber optic sensor 3 to be tested through the 1*16 optical switch 2 respectively. At the four 1*4 optical switches, the outgoing light of 15 space division channels and 1 standard attenuator is switched every 4 channels by one optical switch and sequentially enters a PD photoelectric conversion 8-11, and the electrical signal converted from the optical signal is sampled by the oscilloscope and the display and control terminal computer 12. Each channel can contain 16 time division pulses, and the oscilloscope and the display and control terminal computer 12 process and obtain the optical path loss of the sample to be measured. Then the channel data of 15 space divisions and 16 time divisions can be all processed sequentially.

[0030] The fiber optic hydrophone array with 15 space divisions and 16 time divisions is used as the fiber optic sensor 3 to be tested in this embodiment.

[0031] In the prior art, without structures such as time division, space division, and wavelength division, it can only measure the optical signal power intensity of one optical path at a time. In this embodiment, the tunable wavelength light source 1 is respectively connected to 15 physically spatially independent optical paths of the fiber optic sensor 3 to be tested through the 1*16 optical switch 2, so that 15 optical paths can be sequentially measured, that is, a space division structure can be formed.

[0032] In this embodiment, the fiber optic sensor 3 to be tested has 16 wavelengths. Each time, the wavelength value of the light source can be directly changed or a wavelength of a multi-wavelength light source can be selected by using DWDM and an optical switch for measurement. The oscilloscope and the display and control terminal computer 12 have 4 channels and can simultaneously test 4 wavelengths, a total of 16 wavelengths. This is the wavelength division structure.

[0033] When the incident light is continuous light, only one power value can be measured each time. If the incident light is pulsed light, multiple pulses can be emitted in sequence within one period, and the height of each pulse can be read on the oscilloscope, the display and control computer 12, or the data acquisition device, which is the time-division structure.

[0034] When structures such as time-division, space-division, and wavelength-division are available, 15 space-divisions, 16 wavelength-divisions, and 4 time-divisions can be measured in one test.

[0035] Step 1: As Figure 1 shown, the tunable wavelength light source (1) emits an optical pulse signal of a certain set channel among a total of 16 channels from ITU C20 to C50 according to the frequency set by the host computer, and exports it through an optical jumper.

[0036] Step 2: After the signal of the tunable wavelength light source 1 is exported through the optical jumper, it passes through a 1×16 optical switch 2. The light output ports are 16-way flanges, which respectively enter the space-division channels of the 15 space-division and 16 time-division fiber optic hydrophone array or the standard attenuator. The main function of the 1×16 optical switch 2 is to output the signal of the light source 1 to the 16-way flanges respectively through the time-division multiplexing method.

[0037] Step 3: Divide the 16-way output light flanges of the 15 space-division channels and 1 standard attenuator into 4 groups, with 4 in each group, and each group is connected to the 4-port side of a 1×4 optical switch 4 to 7. At the four optical switches, every 4-way flanges are switched by an optical switch and sequentially enter a PD photoelectric converter 8 to 11. The main function of the PD photoelectric conversion is to convert the input optical signal within a certain wavelength range into a current signal linearly related to its power through the InGaAs semiconductor material.

[0038] Step 4: The electrical signals converted from the optical signals by the PD photoelectric conversions 8 to 11 are transferred to the BNC interface of the oscilloscope and the display and control computer 12 through the SMA interface for sampling. Each channel can contain 16 time-division pulses. The data collected by the total 4 channels of the oscilloscope and the display and control computer 12 are transmitted into the computer through the network cable or serial port, and the optical path loss of the measured sample is obtained by processing according to Appendix B in HX 13023-2020. According to the time-division multiplexing method, the channel data of 15 space-divisions and 16 time-divisions can all be processed sequentially.

[0039] Step 5: Change the frequency or wavelength of the light emitted by the tunable wavelength light source 1 to measure the optical path loss of multiple wavelength-divisions of the fiber optic sensor 3 to be measured.

[0040] As described above, it is only the specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims described above.

Claims

1. A measuring method for a measuring device using a fast-measuring fiber optic sensor array, characterized in that: The measuring device for the fast-measuring fiber optic sensor array includes a tunable wavelength light source (1). The tunable wavelength light source (1) emits pulsed optical signals. The tunable wavelength light source (1) is connected to a 1×M optical switch. The fiber optic sensor to be measured (3) is connected to the other end of the 1×M optical switch. The fiber optic sensor to be measured (3) is simultaneously connected to a number of 1×N optical switches. The number of 1×N optical switches are respectively connected to a number of PD photoelectric conversions. The number of PD photoelectric conversions are simultaneously connected to an oscilloscope and a display and control terminal computer (12), where M is greater than or equal to N. It includes the following steps: Step 1: The tunable wavelength light source (1) emits optical pulse signals, which are led out by an optical jumper cable. Step 2: After the signals of the tunable wavelength light source (1) are led out by the optical jumper cable, they enter the fiber optic sensor to be measured (3) respectively through the 1×M optical switch. The 1×M optical switch outputs the signals of the tunable wavelength light source (1) to M optical flanges respectively through time-division multiplexing. Step 3: The M optical output flanges are divided into N groups and each group enters a 1×N optical switch respectively. After entering the 1×N optical switch, they enter a number of PD photoelectric conversions in sequence. Step 4: The electrical signals converted from the optical signals by the PD photoelectric conversions are transferred to the BNC interfaces of the oscilloscope and the display and control terminal computer (12) through SMA interfaces for sampling. The data collected by a total of several channels of the oscilloscope and the display and control terminal computer (12) are transmitted into the computer through network cables or serial ports. Each channel may contain M time-division pulses. The optical path loss of the fiber optic sensor to be measured (3) is obtained by processing according to Appendix B in HX 13023-2020. According to the time-division multiplexing method, the channel data of space-division and time-division can all be processed sequentially. Step 5: Change the frequency or wavelength of the light emitted by the tunable wavelength light source (1) so as to measure the optical path losses of multiple wavelength divisions of the fiber optic sensor to be measured (3).

2. The measuring method for a measuring device using a fast-measuring fiber optic sensor array according to claim 1, characterized in that: The wavelength range of the light emitted by the tunable wavelength light source (1) is 1537.40 nm to 1561.42 nm.

3. The measuring method for a measuring device using a fast-measuring fiber optic sensor array according to claim 1, characterized in that: M is 16 and N is 4.

4. The measuring method for a measuring device using a fast-measuring fiber optic sensor array according to claim 1, characterized in that: The material of the PD photoelectric conversion is InGaAs semiconductor, and its function is to convert the input optical signals within a certain wavelength range into current signals linearly related to their power.

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