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    • 专利摘要:
    The invention relates to a temperature control method and apparatus, as well as to a fiber-based network detection system, relating to the technical field of optical fiber sensors. The fiber network sensing system includes a dense wavelength division multiplexer, a temperature monitor, a fiber network sensor array and a controller. The controller is configured to acquire an operating temperature change amount from the fiber network sensor assembly, obtain a temperature adjustment amount according to a predefined ruler, and send the temperature adjustment amount to the device. temperature monitoring. The temperature monitoring apparatus is configured to set an operating temperature of the dense wavelength division multiplexer based on the amount of temperature adjustment received and a predefined initial operating temperature. The fiber network sensing system provided by the present invention can function normally in the case where the ambient operating temperature of the fiber array sensor array varies over a wide range, and is applicable in a set of detectors or from hydrophones to network on fiber on a large scale.
    公开号:FR3057678A1
    申请号:FR1750157
    申请日:2017-01-06
    公开日:2018-04-20
    发明作者:Faxiang Zhang；Chang Wang；Jiasheng NI；Gangding PENG；Shaodong Jiang；Xiaolei ZHANG；Ii Min；Shujuan Li；Meng Wang；Zhihui Sun
    申请人:Laser Inst Of Shandong Academy Of Science；Laser Institute of Shandong Academy of Science；
    IPC主号:
    专利说明:

    Holder (s): LASER INSTITUTE OF SHANDONG ACADEMY OF SCIENCE.
    Extension request (s)
    Agent (s): REGIMBEAU.
    FR 3 057 678 - A1 (54) METHOD AND APPARATUS FOR CONTROLLING TEMPERATURE AND FIBER NETWORK DETECTION SYSTEM.
    The invention relates to a large-scale fiber network method and apparatus.
    temperature control, as well as a fiber network detection system, relating to the technical field of fiber optic sensors. The fiber network detection system includes a dense wavelength division multiplexer, a temperature monitoring apparatus, a set of fiber network sensors and a controller. The controller is configured to acquire an operating temperature change amount from the fiber network sensor assembly, obtain a temperature set amount according to a predefined rule, and send the temperature set amount to the device. temperature monitoring. The temperature monitoring apparatus is configured to set an operating temperature of the dense wavelength division multiplexer based on the received temperature setting amount and a predefined initial operating temperature. The fiber network detection system provided by the present invention can operate normally in the case where the ambient operating temperature of the fiber network sensor assembly varies within a wide range, and is applicable in a set of detectors or hydrophones at
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    Temperature control method and apparatus and fiber network detection system
    Technical area
    The present invention relates to the technical field of fiber optic sensors, and in particular to a temperature control method and apparatus as well as to a fiber network detection system.
    Context of the invention
    A fiber network sensor is a sensor that detects an external signal by modulating a Bragg network on fiber (FBG) with the external signal, during which the stress in the FBG changes so as to cause a change in central wavelength of the reflected light, then detecting the change in central wavelength. The fiber network sensor has significant advantages in terms of sensitivity, dynamic range width, reliability, multiplexing capacity and others, compared to traditional electromagnetic sensors; it is therefore an important orientation for the development of high performance sensors.
    When measuring a dynamic signal with the FBG, a dynamic change in wavelength can be detected using a filtering method, such as a tunable and fiber-optic Fabry-Perot filtering method (FFP). rapid scanning, an FBG matching method or a marginal filtering method, and an unbalanced interferometer demodulation method. Among them, the unbalanced interferometer demodulation method has the highest wavelength resolution and a wider frequency range, and therefore has good prospects for application for the detection of weak dynamic signals (e.g. vibration and sound). If the unbalanced interferometer demodulation method were combined with wavelength division multiplexing technology, a fiber network detection system with high wavelength resolution would be formed.
    However, in practical engineering applications, for example, in a set of fiber network detectors or a set of fiber network hydrophones, in an application environment where the temperature varies over a wide range, the length of center wave of the FGB would be likely to exit a channel from a wavelength division multiplexer since the FBG itself is extremely sensitive to temperature, thereby preventing the fiber array detection system from functioning normally.
    i
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    Description of the invention
    In this context, the object of the present invention is to provide a temperature control method and apparatus as well as a network detection system on fiber, with the aim of effectively solving the problem according to which the central wavelengths of the individual fiber networks in the fiber network sensor set would be susceptible to out of the functional wavelengths of the corresponding channels of the wavelength division multiplexer, which would otherwise prevent the fiber network detection system to operate normally.
    To achieve the above object, the present invention adopts technical solutions as follows.
    In a first aspect, an embodiment of the present invention provides a fiber network detection system, which comprises a dense wavelength division multiplexer, a temperature monitoring apparatus, a set of network sensors fiber and a controller. Each of the fiber array sensor set, controller and temperature monitor is coupled to the dense wavelength division multiplexer, and the controller is paired to the temperature monitor . The controller is configured to acquire an operating temperature change amount from the fiber network sensor assembly, obtain a temperature set amount according to a predefined rule, and send the temperature set amount to the device. temperature monitoring. The temperature monitor is configured to set an operating temperature of the dense wavelength division multiplexer based on the amount of temperature setting received and a predefined initial operating temperature.
    In a preferred embodiment of the present invention, the temperature monitoring apparatus includes a temperature change sheet, a first temperature sensor and a temperature control circuit. The temperature change sheet and the first temperature sensor are both mounted on the dense wavelength division multiplexer, the temperature change sheet and the first temperature sensor are both coupled with the temperature control, and the temperature control circuit is coupled with the controller.
    In a preferred embodiment of the present invention, the temperature change sheet is a semiconductor cooler.
    In a preferred embodiment of the present invention, the fiber network detection system further includes a second temperature sensor coupled to the controller. The second temperature sensor is
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    PO1651122JN configured to collect the operating temperature of the fiber network sensor set and send the collected operating temperature to the controller.
    In a preferred embodiment of the present invention, the fiber network detection system further comprises a light source module, an interferometer and a detector. The detector is coupled with the controller. The light signal emitted from the light source module is transmitted to the fiber network sensor set and enters, after being reflected by the fiber network sensor set, into the interference interferometer. The interference signals emitted by the interferometer enter the dense wavelength division multiplexer to undergo a wavelength separation process implemented by the dense wavelength division multiplexer, and are then incidents on the detector. The interferometer is a Michelson fiber optic interferometer with unequal arm lengths.
    In a preferred embodiment of the present invention, the fiber optic Michelson interferometer comprises two fiber arms, with one of the fiber arms wound on a fiber modulator, where the fiber modulator is coupled with a generator signal and the signal generator is coupled with the controller.
    In a preferred embodiment of the present invention, the dense wavelength division multiplexer is a selective planar thermal network.
    In a second aspect, an embodiment of the present invention further comprises a temperature control method applied to the fiber network detection system described above. The method includes: acquiring an operating temperature change amount of the fiber array sensor assembly, and obtaining a temperature control amount in accordance with a predefined rule; and sending the temperature setting amount to the temperature monitoring apparatus, so that the temperature monitoring apparatus adjusts the operating temperature of the dense wavelength division multiplexer on the basis the amount of temperature control and an initial operating temperature of the dense wavelength division multiplexer.
    In a preferred embodiment of the present invention, the step of acquiring an operating temperature change amount of the fiber array sensor set and obtaining a temperature setting amount according to a predefined rule comprises : the acquisition of a current operating temperature of the set of sensors on a network on fiber, and the obtaining of a difference between the operating temperature acquired of the set of sensors on a network
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    PO1651122JN on fiber and a preset temperature as a change amount; and obtaining a temperature setting amount based on a first temperature coefficient and a second temperature coefficient, which are predefined, as well as the amount of change, if the amount of change exceeds one predefined range, where the first temperature coefficient is a temperature sensitivity of the array of fiber network sensors, and the second temperature coefficient is a temperature sensitivity of the dense wavelength division multiplexer.
    In a third aspect, an embodiment of the present invention further includes a temperature control apparatus operating in the controller of the fiber network detection system described above. The temperature controller includes an acquisition module and a sending module. The acquisition module is configured to acquire an amount of operating temperature change from the fiber array sensor set and obtain an amount of temperature setting in accordance with a predefined rule. The send module is configured to send the temperature setting amount to the temperature monitor so that the temperature monitor sets an operating temperature of the wavelength division multiplexer dense based on the amount of temperature setting and an initial operating temperature of the dense wavelength division multiplexer.
    With the fiber network detection system provided by the embodiment of the present invention, the temperature monitoring apparatus is provided for monitoring and controlling the operating temperature of the dense wavelength division multiplexer, and the controller is provided to acquire an amount of operating temperature change from the fiber network sensor assembly, obtain a temperature setting amount according to a predefined rule, and send the obtained temperature setting amount to the device temperature monitoring device, so that the temperature monitoring device adjusts the operating temperature of the dense wavelength division multiplexer on the basis of the temperature setting amount obtained and the current operating temperature of the dense wavelength division multiplexer. In this way, it is able to prevent the central wavelengths of the individual fiber network sensors in the fiber network sensor set from going out of the functional wave ranges of the corresponding multiplexing channels of the multiplexer by dense wavelength distribution, influenced by changes in the external ambient temperature; and therefore, it is effectively guaranteed that the fiber network detection system can operate normally in the event that the temperature
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    PO1651122JN ambient operating range of the fiber array sensor assembly varies over a wide range.
    Brief description of the drawings
    To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings necessary for the embodiments will be presented briefly below. It is understood that the drawings below simply illustrate certain embodiments of the present invention, and should therefore not be interpreted as limiting the scope of the present invention. For those skilled in the art, other relevant drawings can also be obtained from these drawings without any creative work.
    Figure 1 is a schematic structural view of a fiber network detection system provided by a first embodiment of the present invention;
    Figure 2 is a schematic view showing spectra of the fiber network detection system provided by the first embodiment of the present invention;
    Figure 3 is a schematic view showing the packaging of a temperature monitoring apparatus and a dense wavelength division multiplexer provided by the first embodiment of the present invention;
    Figure 4 is a schematic structural view of an interferometer provided by the first embodiment of the present invention;
    Figure 5 is a schematic structural view of a controller provided by the first embodiment of the present invention;
    Figure 6 is a flow diagram of a temperature control method provided by a second embodiment of the present invention;
    Figure 7 is a flow diagram of another temperature control method provided by the second embodiment of the present invention;
    Figure 8 is a block diagram showing the functional modules of a temperature control apparatus provided by a third embodiment of the present invention; and Figure 9 is a block diagram showing the functional modules of another temperature control apparatus provided by the third embodiment of the present invention.
    In the drawings: 10-network fiber detection system; 11-light source module; 12-circulator; 13-set of network sensors on
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    PO1651122JN fiber; 14-interferometer; 141-fiber coupler; 142-fiber arm; 143 Faraday fiber rotation reflector; 144-fiber modulator; 145 signal generator; 15-dense wavelength division multiplexer; 16-temperature monitoring device; 161 — temperature change sheet; 162-first temperature sensor; 163 temperature control circuit; 164-thermal conductive medium; 165 thermal insulation material; 17-detector; 18-controller; 181 — synchronous collection unit; 182-signal processing unit; 80-temperature control device; 81-acquisition module; 811-change quantity acquisition sub-module; 812-temperature control quantity acquisition sub-module; 82-sending module.
    Detailed description of the embodiments
    In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be described below in a clear and complete manner in association with the drawings of embodiments of the present invention. Obviously, the embodiments to be described constitute some, but not all, of the embodiments of the present invention. Generally, the components of the embodiments of the present invention, as described and illustrated in the figures herein, can be arranged and designed in extremely varied configurations.
    Therefore, the following detailed description of the embodiments of the present invention, as shown in the drawings, is not intended to limit the scope of the present invention as claimed, but merely represents selected embodiments of the present invention. All the other embodiments, obtained by a person skilled in the art in the light of the embodiments of the present invention without any creative work, will fall within the scope of protection of the present invention.
    It should be noted that similar reference letters and numbers refer to similar elements in the following drawings, and thus, once an element is defined in a figure, it will not be defined or explained further in the figures following.
    In the description of the present invention, it should be noted that the orientation or positional relationships indicated by the terms, such as "center", "up", "down", "left" and "right", are based on orientation or positional relationships as shown in the drawings, or orientation or positional relationships in which the product provided by the present invention is traditionally placed for its use; these terms are used solely for the purpose of describing the present invention and simplifying the description, rather than indicating or suggesting that the
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    PO1651122JN devices or designated elements must be oriented in a particular way or be constructed or used with a particular orientation, and should not therefore be interpreted as limiting the present invention. In addition, terms such as "first" and "second" are used only to distinguish the description, and should not be understood as indicating or suggesting relative importance.
    In the description of the present invention, it should also be indicated that, unless expressly specified or defined otherwise, the terms "supply", "mount", "couple" and "connect" and their conjugations must be understood in the broad sense. For example, coupling can refer to a direct coupling or a communication link between two elements, or can also refer to an indirect coupling or a communication link via communication modules or interfaces, and can be in electrical, mechanical or other forms. The specific meanings of the terms mentioned above in the present invention can be understood by the skilled person depending on the specific situations.
    In practical engineering applications of fiber network detection systems, in an application environment where the temperature varies over a wide range, the central wavelength of the fiber network would be likely to be out of a wave range of a multiplexer channel since the fiber network itself is extremely sensitive to temperature, thus preventing the fiber network detection system from operating normally. For example, the fiber network has a temperature sensitivity of around 10 µm / ° C, while a 100 GHz dense wavelength division multiplexer has a channel bandwidth of around 300 µm; thus, the fiber network has an operating temperature range of about 30 ° C, which is far from responding to application environments varying over a wide range. If a dense wavelength division multiplexer with a larger bandwidth, such as a bandwidth of 200 GHz or more, is used, although it allows the operating temperature range of the fiber network d to be extended, for a light source with a determined spectral width, extending the bandwidth of the multiplexer by dense wavelength distribution would decrease the multiplexing density and reduce the number of fiber networks in a multiplexing, which has a drawback for reducing the cost of the system.
    In order to meet the requirements of practical engineering applications, in the prior art, the problem of temperature drift of a fiber network is mainly solved by controlling the operating temperature of the fiber network. However, a set of fiber network sensors in a fiber network detection system generally includes a plurality of fiber networks arranged in a distributed manner, which makes it difficult
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    PO1651122JN and expensive to control the operating temperatures of fiber networks.
    The inventors have found by studies that, in the detection system on a fiber network, in the case where the central wavelength of the network on fiber leaves the functional wave range of the corresponding channel of the length-division multiplexer dense wave under the influence of a change in the ambient temperature, the operating temperature of the dense wavelength division multiplexer can be controlled so that the functional wave ranges of the individual multiplexing channels of the multiplexer by dense wavelength distribution also deviate correspondingly, so that the central wavelength of the fiber network, which deviated under the influence of the change in ambient temperature, is maintained in the functional wavelength range of the corresponding multiplexing channel of the dense wavelength division multiplexer, thus ensuring if the normal operation of the fiber network detection system.
    First embodiment
    As shown in FIG. 1, the present embodiment provides a fiber network detection system 10, which comprises a light source module 11, a circulator 12, a set of fiber network sensors 13, an interferometer 14, a dense wavelength division multiplexer 15, a temperature monitoring device 16, a detector 17 and a controller 18.
    Here, the light source module 11 is a broadband continuum light source. For example, a continually amplified spontaneous emission (ASE) light source with a C + L wavelength having a wavelength between 1525 nm and 1595 nm can be used.
    The fiber array sensor 13 includes a plurality of fiber array sensors having different central wavelengths. In addition, the wavelength variation ranges of the plurality of fiber array sensors do not overlap. In the present embodiment, the central wavelengths of the individual fiber network sensors are preferably separated with an interval of 100 GHz (0.8 nm) according to ITU standards. The individual fiber network sensors are connected in series, for example, they can be connected in series by fusion with the loss at fusion preferably controlled in a proportion of 0.1 dB.
    In the present embodiment, the dense wavelength division multiplexer 15 is a temperature sensitive dense wavelength division multiplexer having N multiplexing channels, where N is an integer greater than or equal to 1 For example, in the case of a wideband continuum light source with a bandwidth of
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    PO1651122JN nm and a 100 GHz dense wavelength division multiplexer for which N is 80, the number of fiber network sensors included in the fiber network sensor set is greater than or equal to 1 and less than or equal to 80. In the present embodiment, a thermal selective planar array (AWG) device can be used as a dense wavelength division multiplexer.
    At an initial operating temperature, the central wavelengths of the individual multiplexing channels of the dense wavelength division multiplexer 15 unequivocally correspond to the central wavelengths of the individual fiber array sensors as a whole of fiber network sensors 13. For example, in the case where there are 60 fiber network sensors, the central wavelengths of these are Λ 6 ο, λ 59 , ..., λ 02 and λ Ο ι, respectively, the dense wavelength division multiplexer 15 comprises at least 60 multiplexing channels which are indicated by C60, C59 ..... C02 and C01, respectively.
    In this case, as shown in Figure 2, the central wavelength of a fiber network sensor corresponds to the central wavelength of the functional wavelength of a multiplexing channel. It should be noted that the initial operating temperature is determined by the specific parameters of the set of fiber network sensors 13 and of the dense wavelength division multiplexer 15 actually used. Specifically, the initial operating temperature is an operating temperature necessary to cause the center wavelengths of the individual multiplexing channels of the dense wavelength division multiplexer 15 to be unequivocally corresponding to the lengths of the central wave of the individual fiber network sensors in the fiber network sensor assembly 13 when the fiber network sensor assembly 13 operates at a specified temperature. The specified temperature generally refers to the room temperature (25 ° C).
    The temperature monitoring apparatus 16 is coupled with the controller 18 and the dense wavelength division multiplexer 15. Here, the controller 18 is configured to acquire an amount of operating temperature change from the sensor assembly on a fiber network 13, obtain a temperature setting amount according to a predefined rule, and send the temperature setting amount to the temperature monitor 16. The temperature monitor 16 is configured to set the operating temperature of the dense wavelength division multiplexer 15 based on the received temperature setting amount and the predefined initial operating temperature. It should be noted that the amount of temperature adjustment is an amount of temperature adjustment with respect to the initial operating temperature of the wavelength division multiplexer.
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    PO1651122JN dense 15. For example, assuming that the initial operating temperature of the dense wavelength division multiplexer 15 is 25 ° C and the amount of temperature setting is 20 ° C, if the current operating temperature of the multiplexer by dense wavelength distribution 15 is also 25 ° C, it is necessary to adjust the operating temperature of the multiplexer by dense wavelength distribution 15 to 45 ° C; and if the current operating temperature of the dense wavelength division multiplexer 15 is 10 ° C, it is also necessary to set the operating temperature of the dense wavelength division multiplexer 15 to 45 ° C.
    Specifically, as shown in Figure 3, the temperature monitoring apparatus 16 includes a temperature change sheet 161, a first temperature sensor 162 and a temperature control circuit 163. The temperature change sheet 161 and the first temperature sensor 162 are both mounted on the dense wavelength division multiplexer 15. The temperature change sheet 161 and the first temperature sensor 162 are both coupled with the control circuit. temperature 163, and the temperature control circuit 163 is coupled with the controller 18. To increase the heat transfer between the dense wavelength division multiplexer 15 and the two from the temperature change sheet 161 and the first temperature sensor 162, the dense wavelength division multiplexer 15 is packaged with the change sheet d e temperature 161 and the first temperature sensor 162 via a thermal conductive medium 164 such as thermal conductive silicon, then they are enveloped by a thermal insulation material 165 such as polyurethane foam, to avoid being influenced by the temperature external ambient.
    Here, the first temperature sensor 162 is configured to monitor the current operating temperature of the dense wavelength division multiplexer 15. The temperature change sheet 161 is configured to change the operating temperature of the length distribution multiplexer dense wave 15 under the control of the temperature control circuit 163. In the present embodiment, it may be preferable to use a semiconductor cooler as the temperature change sheet 161. Certainly, a temperature control device such as an electric heating wire can also be used as a temperature change sheet 161.
    In addition, the temperature monitoring apparatus 16 may also include a screen. The screen can be coupled to the temperature control circuit 163 and configured to display the current operating temperature of the dense wavelength division multiplexer 15 collected by the first temperature sensor 162.
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    As an implementation, in the absence of receiving an external control instruction including the temperature setting amount, the temperature control circuit 163 can control the operation of the temperature change sheet 161 based on of the current operating temperature of the dense wavelength division multiplexer 15 collected by the first temperature sensor 162 and the above mentioned initial operating temperature, so that the operating temperature of the dense wavelength division multiplexer 15 is always maintained at the above-mentioned initial operating temperature. Upon receipt of the external control instruction including the temperature setting amount, the temperature control circuit 163 controls the operation of the temperature change sheet 161 based on the received temperature setting amount and the current operating temperature of the dense wavelength division multiplexer 15, in order to adjust the operating temperature of the dense wavelength distribution multiplexer 15. For example, if the initial operating temperature of the dense distribution multiplexer 15 dense wavelength 15 is 25 ° C and the temperature setting amount is -40 ° C, it is necessary to adjust the operating temperature of the multiplexer by dense wavelength distribution 15 to -15 ° C by controlling the operation of the temperature change sheet 161.
    Concerning the controller 18 which acquires a quantity of operating temperature change of the set of fiber network sensors 13 and obtains a quantity of temperature adjustment in accordance with a predefined rule, it can be carried out as follows. A second temperature sensor is provided in the functional environment of the fiber network sensor assembly 13, and it is coupled with the controller 18. The second temperature sensor is configured to collect the operating temperature of the assembly of fiber network sensors 13 and send the collected operating temperature to controller 18. After acquiring the current operating temperature of the fiber network sensor assembly 13, controller 18 obtains a difference between the temperature of current operation of the fiber network sensor array 13 and the preset temperature as an amount of change. If the amount of change exceeds a predefined range, the amount of temperature setting is obtained based on a first temperature coefficient and a second temperature coefficient, which are predefined, as well as the amount of change. Here, the first temperature coefficient is a temperature sensitivity of the array of fiber network sensors 13, and the second temperature coefficient is a temperature sensitivity of the dense wavelength division multiplexer 15. The predefined range can be defined in accordance with the bandwidth of the dense wavelength division multiplexer 15 and the temperature sensitivity of the fiber array sensor assembly 13. For example, in the case where a
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    PO165I122JN 100 GHz thermal AWG device with a channel bandwidth of about 0.3 nm is used as a dense wavelength division multiplexer 15 and the fiber network has a temperature sensitivity of about 10 µm / ° C, the fiber array sensor has an operating temperature range of approximately 30 ° C. In this case, the preset range can be [-15, 15], and the amount of temperature setting will be calculated if the change in operating temperature of the fiber array sensor array 13 exceeds the preset range.
    Specifically, the amount of temperature control AT can be obtained from a formula A7 = 7i * Ci / C 2 . Here, 7) represents the amount of change described above, Ci represents the first temperature coefficient, and C 2 represents the second temperature coefficient. For example, in the case where the specified temperature is 25 ° C and the current operating temperature of the fiber array sensor assembly 13 is 45 ° C, Ti is 20 ° C.
    In addition, for a field of application for which the general temperature change is already known, concerning the controller 18 which acquires the amount of operating temperature change of the network of fiber network sensors 13 and obtains the amount of adjustment temperature in accordance with the predefined rule, it can also be carried out as follows: the temperature information relating to this domain is programmed in a timing control program to be stored beforehand in a memory, and the controller 18 executes the control program time delay so as to send a corresponding temperature setting amount to the temperature monitoring apparatus 16 based on the predefined time information. It should be noted that the error in estimating or measuring the temperature in this area should not exceed ± 5 ° C. In this way, the operating temperature of the dense wavelength division multiplexer 15 can vary with the change of the operating temperature of the fiber array sensor assembly 13, so as to maintain the one-to-one correspondence between the central wavelengths of the individual fiber network sensors in the fiber network sensor assembly 13 and the central wavelengths of the individual multiplexing channels of the dense wavelength division multiplexer 15, thus guaranteeing the normal operation of the fiber network detection system 10.
    In addition, in the fiber network detection system 10 provided by this embodiment, the interferometer 14 is an unbalanced interferometer, for which a Michelson fiber optic interferometer or a Mach-Zehnder fiber optic interferometer can be used. It can be understood that a fiber optic interferometer can cause polarization fading and random phase fading due to external environmental disturbances. Here, the fainting of
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    PO1651122JN polarization means that a common single-mode fiber can cause a random change in the polarization states of two coherent light beams due to the presence of a birefringence effect, which consequently results in a change in the visibility of a signal. interference emitted by the interferometer 14, and in particular when the polarization states of the two coherent light beams are orthogonal to each other, the interference signal emitted by the interferometer 14 would disappear completely, causing a signal fading effect induced by polarization . Random phase fading means that a phase shift of an optical signal transmitted in a fiber arm of the interferometer 14 would be caused due to the influence of external environmental disturbances on the fiber arm, leading to a fading of the interference signal from the interferometer 14.
    To solve the polarization fading problem existing in the interferometer 14, in this embodiment, the interferometer 14 is preferably made as a Michelson fiber optic interferometer with unequal arm lengths.
    Specifically, as shown in Figure 4, the interferometer 14 includes a fiber coupler 141, two fiber arms 142 and two Faraday fiber rotation reflectors 143, and a light signal is transmitted in a direction indicated by the arrows as shown in Figure 4. Each fiber arm 142 has one end thereof coupled with a connection end of the fiber coupler 141, and the other end of each fiber arm 142 is coupled with a rotation reflector of Faraday to fiber 143. By providing the rotation reflectors of Faraday to fiber 143, the polarization fading existing in the interferometer 14 can be effectively eliminated, and the signal-to-noise ratio of the interference signal emitted by the interferometer 14 can be increased.
    Here, a 2x2 fiber coupler with a division ratio of 50:50 can be used as the fiber coupler 141. The difference between the arm lengths of the two fiber arms 142 is specifically defined according to the requirement of resolution of the system and the coherence length of the fiber network sensor. In the present embodiment, the difference between the arm lengths of the two fiber arms 142 can be provided to be between 4 and 6 mm, for example, 5 mm.
    In addition, to further eliminate the influence of random phase fading in the interferometer 14, as an implementation, a fiber arm 142 of the interferometer 14 is wound on a fiber modulator 144, like the shown in Figure 4. The fiber modulator 144 is a phase modulator and, in the present embodiment, the fiber modulator 144 can be a radially polarized piezoelectric ceramic ring. The fiber modulator 144 is coupled with a signal generator 145, which is itself coupled
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    PO1651122JN with controller 18. In this case, a sinusoidal signal from the signal generator 145 can be controlled by a predefined phase-generated carrier (PGC) algorithm, so that the fiber modulator 144 is controlled to apply a signal phase modulation to the fiber arm 142; in this way, the phase difference concerning the interference signal emitted by the interferometer 14 is modulated by modulating the light signal transmitted in the fiber arm 142, thus eliminating the influence of the random phase fading in the interferometer 14. In the present embodiment, the signal generator 145 can be a circuit board generating a standard sinusoidal signal, and can of course also be a digital signal generator.
    In addition, the detector 17 is an array of photodetectors comprising a plurality of photodetectors. For example, the set of fiber network sensors 13 comprises M fiber network sensors, consequently, the dense wavelength division multiplexer 15 comprises at least M multiplexing channels, and the photodetector network comprises at least minus M photodetectors. Each photodetector is connected to a multiplexing channel of the dense wavelength division multiplexer 15, collects an interference signal emitted by the multiplexing channel, converts the collected interference signal into an electrical signal, then sends it to the controller 18. In the present embodiment, a detection circuit by semiconductor InGaAs PIN type photodiode accompanied by a preamplifier circuit can be used as a photodetector.
    In the present embodiment, as shown in Figure 5, the controller 18 includes a synchronous collection unit 181 and a signal processing unit 182. With regard to the synchronous collection unit 181, the number of bits is greater than 16 , and the number of channels is greater than N + 1. One of the channels of the synchronous collection unit 181 is configured to collect the signal generated by the signal generator 145. The signal processing unit 182 can be an integrated circuit chip capable of processing a signal, such as a microcontroller, an ARM, DSP or FPGA. In addition to acquiring the amount of operating temperature change of the fiber network sensor assembly 13, obtaining the temperature setting amount in accordance with the predefined rule and sending the amount of temperature setting at the temperature monitor 16, the signal processing unit 182 is further configured to restore a wavelength change signal by processing with a length demodulation algorithm based on the carrier algorithm generated in phase or a wavelength demodulation algorithm based on heterodyne detection. It should be noted that the synchronous collection unit 181, the signal processing unit 182 and the signal generator 145 may be separate components, or may also be components of an integrated circuit.
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    The fiber network detection system 10 provided by the present invention operates on a principle as follows.
    The light emitted from the light source module 11 is transmitted to the set of fiber network sensors 13 via the circulator 12, and is reflected by the set of fiber network sensors 13; the light reflected from the fiber array sensor 13 enters the interferometer 14 via the circulator 12, so that the light reflected from the individual fiber array sensors causes interference so as to form signals interference of different wavelengths, respectively. The interference signals of different wavelengths emitted by the interferometer 14 enter the dense wavelength division multiplexer 15, the plurality of multiplexing channels of the dense wavelength division multiplexer 15 separate the interference signals of different wavelengths, and cause the interference signals of different wavelengths after separation to be incident on the detector 17. The detector 17 converts the received interference signals into electrical signals and sends them to the controller 18 for processing. Here, the central wavelengths of the individual fiber network sensors in the fiber network sensor assembly 13 unequivocally correspond to the central wavelengths of the individual multiplexing channels of the wavelength division multiplexer dense 15.
    The light intensity / interference signal detected by the detector 17 can be expressed as follows:
    / = / 0 (l + £ cos (A ^ + ç 0 )) (1) where l 0 is the intensity of the detected light, k is the visibility of the interference fringes, Δφ is a change in difference of phase between the light signal transmitted in the two fiber arms 142 of the interferometer 14, and φ 0 is an initial phase of the light signal. The fiber network sensor detects an external signal in such a way that the wavelength of the reflected light changes under the influence of the external signal as a constraint. The amount of change Δλ in the wavelength of the light reflected from the fiber network sensor is amplified by the interferometer 14 with a difference in arm length of df, so as to be like a change in phase difference:
    Δφ =
    2πηά,
    -ΔΑ (2) where λ β represents the Bragg wavelength of the fiber network sensor, and n represents the effective refractive index of the fiber network sensor. At
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    PO1651122JN Using phase demodulation techniques, such as a demodulation algorithm based on the carrier algorithm generated in phase or a demodulation algorithm based on heterodyne detection, phase information is extracted from the interference fringes to obtain Δφ. Then, the amount of change Δλ in the wavelength of the fiber network sensor is obtained by formula (2), allowing detection of wavelength with high resolution.
    With the fiber network detection system 10 provided by the embodiment of the present invention, the temperature monitoring apparatus 16 is provided to monitor and control the operating temperature of the dense wavelength division multiplexer 15 , and the controller 18 is provided to acquire the amount of operating temperature change of the fiber array sensor assembly 13, obtain the temperature setting amount in accordance with the predefined rule, and send the temperature setting amount obtained at the temperature monitoring apparatus 16, so that the temperature monitoring apparatus 16 adjusts the operating temperature of the dense wavelength division multiplexer 15 based on the amount of temperature setting obtained and the current operating temperature of the length distribution multiplexer d dense wave 15. In this way, it is able to prevent the central wavelengths of the individual fiber network sensors in the fiber network sensor assembly 13 from going out of the functional wave ranges of the corresponding multiplexing of the dense wavelength division multiplexer 15, under the influence of changes in the external ambient temperature; and therefore, it is effectively guaranteed that the fiber network detection system 10 can operate normally in the event that the ambient operating temperature of the fiber network sensor assembly 13 varies over a wide range.
    Second embodiment
    The present embodiment provides a temperature control method applied to the fiber array detection system 10 provided in the first embodiment described above. As shown in Figure 6, the temperature control method includes step S61 and step S62.
    In step S61, an amount of operating temperature change of the fiber array sensor assembly is acquired, and an amount of temperature setting is obtained according to a predefined rule.
    As an implementation, by means of a second temperature sensor provided in the functional environment of the set of fiber network sensors 13, the current operating temperature of the set of
    PO1651122JN
    PO1651122JN fiber network sensors 13 can be collected in real time and sent to the controller 18.
    In this case, as shown in Figure 7, step S61 includes step S71 and step S72 below.
    In step S71, the current operating temperature of the fiber network sensor assembly is acquired, and a difference between the acquired operating temperature of the fiber network sensor assembly and a predefined temperature is obtained by as much amount of change.
    In the case where the fiber array sensor assembly 13 operates at a specified temperature, the central wavelengths of the individual multiplex channels of the dense wavelength division multiplexer 15 at the initial operating temperature correspond to biunivocally to the central wavelengths of the individual fiber network sensors in the fiber network sensor assembly 13. After receiving the current operating temperature of the fiber network sensor assembly 13, the controller 18 can get the difference between the operating temperature acquired from the fiber array sensor assembly 13 and the preset temperature, as the amount of change. The amount of change is an amount of change in operating temperature of the fiber array sensor assembly 13 caused by the change in the external ambient temperature.
    In step S72, a temperature setting amount is obtained based on a first temperature coefficient and a second temperature coefficient, which are predefined, as well as the amount of change, if the amount of change exceeds a predefined range.
    Here, the first temperature coefficient is the temperature sensitivity of the array of fiber network sensors 13, and the second temperature coefficient is the temperature sensitivity of the dense wavelength division multiplexer 15.
    If the amount of operating temperature change of the fiber network sensor assembly 13 exceeds a certain value, the central wavelengths of the individual fiber network sensors in the fiber network sensor assembly 13 may out of the functional wave ranges of the corresponding multiplexing channels of the dense wavelength division multiplexer 15, thereby preventing the fiber array detection system 10 from operating normally. For example, in the case where a 100 GHz thermal AWG device with a channel bandwidth of about 0.3 nm is used as a dense wavelength division multiplexer 15 and the fiber network has a
    PO1651122JN
    PO1651122JN temperature sensitivity of approximately 10 pm / ° C, the fiber array sensor has an operating temperature range of approximately 30 ° C.
    Therefore, in the present embodiment, the amount of change obtained is compared with the preset range, and if the amount of change exceeds the preset range, the amount of temperature setting is obtained based on the first and second coefficients of temperature, which are predefined, as well as the amount of change, so as to control the operating temperature of the dense wavelength division multiplexer 15 based on the amount of temperature setting obtained. In this way, the operating temperature of the dense wavelength division multiplexer 15 can vary with the change of the operating temperature of the set of fiber network sensors 13, so as to guarantee the one-to-one correspondence between the central wavelengths of the individual fiber network sensors in the fiber network sensor assembly 13 and the central wavelengths of the individual multiplexing channels of the dense wavelength division multiplexer 15. Here, the predefined range can be defined in accordance with the bandwidth of the dense wavelength division multiplexer 15 and the temperature sensitivity of the fiber array sensor assembly 13. For example, in the case where the multiplexer by dense wavelength distribution 15 has a channel bandwidth of about 0.3 nm and the fiber network has a sensitivity at a temperature of around 10 pm / ° C, the predefined range can be defined as [-15, 15],
    Specifically, the temperature setting quantity ΔΤ can be obtained from a formula & T = T * Ci / C2. Here, Ti represents the amount of change described above, Ci represents the first temperature coefficient, and C2 represents the second temperature coefficient. For example, in the case where the specified temperature is 25 ° C and the current operating temperature of the fiber array sensor set 13 is 45 ° C, T is 20 ° C.
    If the amount of change does not exceed the predefined range, it means that the operating temperature of the fiber array sensor assembly 13 is within the operating temperature range thereof, and it is not necessary to calculate the temperature setting amount, that is, it is not necessary to perform step S62. In this case, the dense wavelength division multiplexer 15 maintains its current operating temperature.
    In addition to the aforementioned manner, for a field of application for which the general temperature change is already known, concerning the acquisition of the quantity of operating temperature change of the array of fiber network sensors 13 and obtaining the quantity of
    PO1651122JN
    PO1651122JN temperature adjustment in accordance with the predefined rule, this can also be carried out as follows: the temperature information relating to this area is programmed in a timing control program to be stored beforehand in a memory, and the controller 18 executes the program timing control so as to acquire a corresponding temperature setting amount based on the predefined time information. For example, 12:00 p.m. at noon may correspond to a temperature setting amount of 20 degrees, and 7:00 p.m. in the evening may correspond to a temperature setting amount of -20 degrees.
    In step S62, the temperature setting amount is sent to the temperature monitoring apparatus, so that the temperature monitoring apparatus adjusts the operating temperature of the dense wavelength division multiplexer over the based on the amount of temperature control and the initial operating temperature of the dense wavelength division multiplexer.
    After receiving the amount of temperature control sent from the controller 18, the temperature monitoring apparatus 16 adjusts the operating temperature of the dense wavelength division multiplexer 15 based on the amount of temperature control and of the initial operating temperature of the dense wavelength division multiplexer 15. For example, in the case where the initial operating temperature of the dense wavelength division multiplexer 15 is 25 ° C and the amount of setting temperature is 20 ° C, it is necessary to adjust the operating temperature of the multiplexer by dense wavelength distribution 15 to 45 ° C.
    It will be clear to those skilled in the art that the specific details of the process described above may refer to the corresponding contents described in the system embodiment described above, which will not be repeated herein for convenience and short description.
    The temperature control method provided by this embodiment applies to the fiber network detection system 10 provided in the first embodiment described above, so that the operating temperature of the length-division multiplexer dense wave 15 may vary with the change in operating temperature of the fiber array sensor assembly 13, thereby effectively ensuring that the fiber array detection system 10 can operate normally in the event that the ambient operating temperature of the fiber array sensor assembly 13 varies over a wide range.
    PO1651122JN
    PO1651122JN
    Third embodiment
    The present embodiment provides a temperature control apparatus operating in the controller 18 of the fiber network detection system 10 provided in the first embodiment described above. As shown in Figure 8, the temperature control device 80 includes an acquisition module 81 and a sending module 82.
    Here, the acquisition module 81 is configured to acquire an amount of change in operating temperature of the set of fiber network sensors 13 and obtain an amount of temperature adjustment in accordance with a predefined rule.
    The sending module 82 is configured to send the temperature setting quantity to the temperature monitoring device 16, so that the temperature monitoring device 16 regulates the operating temperature of the length division multiplexer. dense wave 15 based on the amount of temperature setting and an initial operating temperature of the dense wavelength division multiplexer 15.
    Specifically, as shown in FIG. 9, the acquisition module 81 comprises a change quantity acquisition sub-module 811 and a temperature control quantity acquisition sub-module 812.
    Here, the change quantity acquisition sub-module 811 is configured to acquire a current operating temperature of the set of fiber network sensors 13, and obtain a difference between the acquired operating temperature of the set of network sensors on fiber 13 and a preset temperature as the amount of change.
    The temperature control quantity acquisition sub-module 812 is configured to obtain a temperature control quantity based on a first temperature coefficient and a second temperature coefficient, which are predefined, as well as the amount of change, if the amount of change exceeds a predefined range, where the first temperature coefficient is the temperature sensitivity of the array of fiber array sensors 13, and the second temperature coefficient is the sensitivity to dense wavelength division multiplexer temperature 15.
    The above modules can be implemented in software codes, in this case, the aforementioned modules can be stored in a memory included in the controller 18. The above modules can also be implemented in hardware, like an integrated circuit chip.
    PO1651122JN
    PO1651122JN
    With regard to the temperature control apparatus 80 provided by this embodiment, the principle of implementation and the technical effect produced by it are the same as those of the embodiment of method described above. Therefore, the part of the apparatus embodiment which is not mentioned may refer to the corresponding contents in the method embodiment described above, for the purpose of brief description.
    The above description simply illustrates particular embodiments of the present invention, but is not intended to limit the protective field of the present invention. Any modifications, which a person skilled in the art could implement without departing from the technical scope described in the present invention, will fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention falls within the scope of the claims.
    PO1651122JN
    PO1651122JN
    权利要求:
    Claims (11)
    [1" id="c-fr-0001]
    Claims:
    1. Fiber network detection system, characterized in that it comprises a dense wavelength division multiplexer, a temperature monitoring device, a set of fiber network sensors and a controller, each of the the array of fiber network sensors, the controller and the temperature monitoring device being coupled to the dense wavelength division multiplexer, and the controller being coupled to the temperature monitoring device, wherein the controller is configured to acquire an operating temperature change amount from the fiber network sensor assembly, obtain a temperature set amount according to a predefined rule, and send the temperature set amount to the device temperature monitoring; and the temperature monitoring apparatus is configured to set an operating temperature of the dense wavelength division multiplexer based on the amount of temperature setting received and a predefined initial operating temperature.
    [2" id="c-fr-0002]
    2. Fiber network detection system according to claim 1, characterized in that the temperature monitoring apparatus comprises a temperature change sheet, a first temperature sensor and a temperature control circuit, the change sheet temperature and the first temperature sensor are both mounted on the dense wavelength division multiplexer, the temperature change sheet and the first temperature sensor are both coupled with the temperature control circuit, and the temperature control circuit is coupled with the controller.
    [3" id="c-fr-0003]
    3. Fiber network detection system according to claim 2, characterized in that the temperature change sheet is a semiconductor cooler.
    [4" id="c-fr-0004]
    4. Fiber network detection system according to claim 1, characterized in that it further comprises a second temperature sensor coupled with the controller, in which the second temperature sensor is configured to collect the operating temperature of the set of fiber network sensors and send the collected operating temperature to the controller.
    [5" id="c-fr-0005]
    5. Fiber network detection system according to claim 1, characterized in that it further comprises a light source module, an interferometer and a detector, in which the detector is coupled
    PO1651122JN
    PO1651122JN with the controller, the light signal emitted from the light source module is transmitted to the set of fiber network sensors and enters, after being reflected by the set of fiber network sensors, into the interferometer for interference, and the interference signals emitted by the interferometer enter the dense wavelength division multiplexer to undergo a wavelength separation process implemented by the wavelength division multiplexer dense, and are then incident on the detector, in which the interferometer is a Michelson fiber optic interferometer with unequal arm lengths.
    [6" id="c-fr-0006]
    6. fiber network detection system according to claim 5, characterized in that the Michelson fiber optic interferometer comprises two fiber arms, with one of the fiber arms wound on a fiber modulator, in which the fiber modulator is coupled with a signal generator and the signal generator is coupled with the controller.
    [7" id="c-fr-0007]
    7. Fiber network detection system according to claim 1, characterized in that the dense wavelength division multiplexer is a selective planar thermal network.
    [8" id="c-fr-0008]
    8. Temperature control method, characterized in that the temperature control method is applied to the fiber network detection system according to any one of claims 1 to 7, in which the method comprises:
    acquiring an operating temperature change amount of the fiber network sensor assembly and obtaining a temperature control amount in accordance with a predefined rule; and sending the temperature setting amount to the temperature monitoring apparatus, so that the temperature monitoring apparatus adjusts the operating temperature of the dense wavelength division multiplexer on the basis the amount of temperature control and an initial operating temperature of the dense wavelength division multiplexer.
    [9" id="c-fr-0009]
    9. A temperature control method according to claim 8, characterized in that the step consisting in acquiring an amount of change in operating temperature of the set of sensors on a fiber network and in obtaining an amount of temperature control in accordance with to a predefined rule includes:
    the acquisition of a current operating temperature of the set of sensors on a network on fiber, and the obtaining of a difference between the operating temperature acquired of the set of
    PO1651122JN
    PO1651122JN network sensors on fiber and a predefined temperature as quantity of change; and obtaining a temperature setting amount based on a first temperature coefficient and a second temperature coefficient, which are predefined, as well as the amount of change, if the amount of change exceeds one predefined range, wherein the first temperature coefficient is a temperature sensitivity of the array of fiber network sensors, and the second temperature coefficient is a temperature sensitivity of the dense wavelength division multiplexer.
    [10" id="c-fr-0010]
    10. Temperature control device, characterized in that it operates in the controller of the fiber network detection system according to any one of claims 1 to 7, in which the temperature control device comprises:
    an acquisition module configured to acquire an amount of change in operating temperature of the set of sensors on a network on fiber and obtain an amount of temperature adjustment in accordance with a predefined rule; and a send module configured to send the temperature setting amount to the temperature monitor so that the temperature monitor sets the operating temperature of the wavelength division multiplexer dense based on the amount of temperature setting and an initial operating temperature of the dense wavelength division multiplexer.
    PO1651122JN
    PO1651122JN
    [11" id="c-fr-0011]
    11-.
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    优先权:
    申请号 | 申请日 | 专利标题
    CN201610911419.1A|CN106482864A|2016-10-19|2016-10-19|A kind of temperature-controlled process, device and fiber grating sensing system|
    CN201610911419.1|2016-10-19|
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