CN203704951U - Fiber grating demodulation instrument - Google Patents
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- CN203704951U CN203704951U CN201320659806.2U CN201320659806U CN203704951U CN 203704951 U CN203704951 U CN 203704951U CN 201320659806 U CN201320659806 U CN 201320659806U CN 203704951 U CN203704951 U CN 203704951U
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Abstract
The utility model relates to a fiber grating demodulation instrument. The fiber grating demodulation instrument is characterized in that the fiber grating demodulation instrument comprises a scanning light source (1), a coupler (2) with a coupling ratio of 99:1, a PLC demultiplexer module (3), a plurality of 3 dB couplers (4), a fiber grating array (6), a reference optical path (7), a data acquisition module (12), a main control board (13), an industrial personal computer (17) and a display (18), wherein the reference optical path (7) comprises a first reference grating (8), a second reference grating (9), a third reference grating (10) and a temperature sensor, the temperature sensor is connected with the main control board, a wavelength Lambda 2 of the first reference grating and a wavelength Lambda 3 of the second reference grating (9) are close to one end of a system wavelength, a wavelength Lambda 4 of the third reference grating (10) is close to the other end of the system wavelength, and the proportion of Lambda 4-Lambda 3 to Lambda 3-Lambda 2 ranges from 4:1 to 7:1. Compared with the prior art, according to the fiber grating demodulation instrument, three reference gratings and one temperature sensor are simply employed to replace an expensive FP etalon as the reference optical path, and the influences on the precision and accuracy of demodulation due to the change of the wavelengths outputted by the light source caused by the self creep, lag and drifting of the scanning light source are effectively eliminated.
Description
Technical field
The utility model relates to a kind of fiber Bragg grating (FBG) demodulator.
Background technology
Very extensive in field application such as electric power energy, petrochemical complex, track traffic, tunnel bridges based on optical fiber grating temperature and pressure sensor measurement system in recent years, become a bright spot of economic growth, correlation technique also becomes the focus of people's research.Fiber grating measuring technique can realize at a distance measurement and monitoring in real time, and it is wide to have measurement range, and the feature of high precision and high stability is particularly particularly evident in strong electromagnetic occasion or explosion-proof occasion advantage.
Traditionally, fiber grating demodulation technology adopts spectrometer, and color filter and wavemeter, but the shortcoming such as that these demodulating systems exist is expensive, and volume is large, be not suitable for engineering application.People propose the demodulation method of many applicable engineering application in succession for this reason.Demodulation scheme based on scanning light source is one of at present common demodulation method.The demodulation method of scanning light source is still in essence based on tunable FP technology, on the piezoelectrics PZT on scanning light source FP wave filter, loads certain voltage, regulates interval, PZT chamber, thereby makes scanning light source export specific wavelength.Because piezoelectrics PZT structure itself exists the shortcomings such as creep, hysteresis and drift, therefore (FBG) demodulator need to have reference path to revise demodulation wavelength, to eliminate these impacts, the accuracy that improves demodulating system.Traditional way is that reference path adopts the FP etalon of good thermal stability to realize, but FP etalon is expensive, is only suitable for Laboratory Principle checking, is not suitable for practical implementation.Simultaneously in hyperchannel application, because grating quantity and the interval of each passage are different, the signal magnitude that causes optical grating reflection to be returned is different, how making grating signal testing circuit have versatility is also the content that demodulation scheme needs are studied with compatibility to adapt to the requirement of different passages, also there is no good solution at present from the prior art of announcing.
Utility model content
Technical problem to be solved in the utility model is to provide a kind of fiber Bragg grating (FBG) demodulator for above-mentioned prior art, this (FBG) demodulator scheme can be eliminated because the creep of scanning light source own, hysteresis and drift make Wavelength demodulation result and exert an influence, thereby correctly demodulates wavelength data.
The utility model solves the problems of the technologies described above adopted technical scheme: this fiber Bragg grating (FBG) demodulator, it is characterized in that: comprise scanning light source, splitting ratio is the coupling mechanism of 99:1, PLC splitter module, multiple three-dB couplers, optical fiber optical grating array, reference path, data acquisition module, master control borad, industrial computer and display, wherein the power input of scanning light source is connected with master control borad, scanning light source is output optical signal under the scanning voltage control of master control borad output, the light signal of scanning light source output enters by the A end of coupling mechanism, the B end of coupling mechanism is 99 part in splitting ratio, the C end of coupling mechanism is 1 part in splitting ratio 1, the B termination PLC splitter module of coupling mechanism, the C end of coupling mechanism enters reference path, each channel output end of PLC splitter module respectively by three-dB coupler laggard enter optical fiber optical grating array, the signal that in optical fiber optical grating array, fiber grating reflects passes to data acquisition module by connected three-dB coupler successively, the output terminal of reference path is also connected with data acquisition module, data acquisition module is connected with master control borad, master control borad is connected with industrial computer, industrial computer is connected with display,
Wherein, described reference path comprise first with reference to grating, second with reference to grating, the 3rd with reference to grating and temperature sensor, temperature sensor is connected with master control borad, above-mentioned three wavelength with reference to grating need to meet certain requirements, could scanning light source be revised and be compensated, to eliminate scanning light source drift, the impact of creep on the measuring precision and stability, simultaneously also can compensated scanning light source non-linear.The grating signal wavelength band that system is chosen is between λ 1 to λ 5, require the wavelength scanning range of scanning light source always between λ 1 to λ 5, make demodulating system not omit grating, guarantee the stability of system works, with reference to grating Criterion of Selecting: the first wavelength X 2 with reference to grating and the second wavelength X 3 with reference to grating are near one end λ 1 of system wavelength, the 3rd wavelength X 4 with reference to grating is near the other end λ 5 of system wavelength, and the ratio of λ 4-λ 3 and λ 3-λ 2 at 4:1 between 7:1.As preferably, get λ 2 and λ 3 near λ 1, λ 4 is near λ 5, and the wavelength difference ratio of λ 4-λ 3 wavelength difference and λ 3-λ 2 is 5:1.
For guaranteeing the relative stability of reference path, need 3 and there is uniform temp with reference to grating.This programme is abandoned the implementation of complicated temperature-control circuit, and adopt simple structural design to realize this function, implementation is: first is all arranged in an aluminium block with reference to grating and temperature sensor with reference to grating, the 3rd with reference to grating, second, on this aluminium block, have U-shaped groove, three with reference to grating and temperature sensor mutually near being arranged in this U-shaped groove, in gap in U-shaped groove, heat conductive silica gel is set simultaneously and fixes, on aluminium block, be added with aluminium sheet sealing.Actual test shows, adopts the temperature error between three gratings of this structure to be less than 0.1 degree Celsius, can meet the requirement of industrial occasions.
Described PLC splitter module is made up of nine 1X8PLC shunts, and wherein the B of coupling mechanism end is connected with the input end of one of them 1X8PLC shunt, and eight output terminals of this 1X8PLC shunt are connected with the input end of eight 1X8PLC shunts that are left respectively.In actual use, can rationally adjust according to number of channels the quantity of 1X8PLC shunt, be configured to required passage, here it should be noted that, in the time of 64 passages of combination, only support 64 passages (comprising 1 road reference channel) historical facts or anecdotes border and can only use 63 passages wherein due to system acquisition system maximum, 1 is alternate channel.
Described data acquisition module is resolved for the extraction and the centre wavelength that realize grating original signal crest, comprise 16 blocks of data collection plates, every blocks of data collection plate 121 has included 4 path channels, collection plate CPU and R232 interface circuit, each path channels is equipped with PIN diode, automatic gain control circuit and analog to digital converter, the analog to digital converter of 4 path channels is connected with collection plate CPU, collection plate CPU is also connected with automatic gain control circuit simultaneously, and then collection plate CPU is connected with active plate by R232 interface circuit.Every blocks of data collection plate can arrange this data acquisition board address by the DIP switch in this data acquisition board, and collection plate CPU controls automatically to the automatic gain control circuit of each path channels.Collection plate CPU adopts the single-chip microcomputer of dominant frequency more than 72MHZ, and analog to digital converter is 12 analog to digital converters of sampling rate more than 1M.
Data acquisition module is adjusted in real time to the enlargement factor of automatic gain control circuit, complete scanning process each time, the amplitude of the fiber grating signal of collection plate CPU to analog to digital converter sampling detects, if maximal value exceedes 0.9 times of analog to digital converter reference value, the corresponding enlargement factor that reduces automatic gain control circuit; If maximal value is less than 0.5 times of analog to digital converter reference value, the enlargement factor of corresponding increase automatic gain control circuit.Adopt the enlargement factor of agc circuit to adjust in real time, be conducive to strengthen versatility and the compatibility of hardware to each passage, can be not inconsistent because of the grating quantity of each passage, distance and length are inconsistent, cause the size of signal different, hardware need to be for the drawback of the independent Design enlargement multiple of each passage.
Described master control borad comprises: amplification and driving circuit, D/A converting circuit and master control borad CPU, master control borad CPU is connected with the input end of D/A converting circuit, the output terminal of D/A converting circuit is connected with the input end of amplification and driving circuit, and the output terminal of amplification and driving circuit is connected with scanning light source.Master control borad CPU adopts the single-chip microcomputer of dominant frequency more than 72MHZ, D/A converting circuit is 16 figure place weighted-voltage D/A converters, master control borad and data acquisition module adopt plate card type connected mode, be specially connector connected mode, communication interface is RS232, master control borad inquire about by timing and interrupt combination mode realize communication more than 1 pair, the automatic identification of the automatic complete paired data acquisition module of master control borad after powering on, identification address is the address of every collection plate DIP switch.
The scanning strategy of described scanning light source is: scanning light source adopts sawtooth voltage to drive, master control borad CPU is by controlling D/A converting circuit, again by amplifying and driving circuit generation sawtooth wave, scanning voltage scope is between 0-50V, complete single pass process comprises three phases: the preparatory stage, forward scan stage and reverse scan stage, time corresponding to each stage is respectively t1, t2 and t3, t2>t3>t1, preparatory stage scanning voltage maintains preparation voltage, duration is t1, act as stabilized light source, for forward scan is prepared, forward scan stage voltage is elevated to maximum voltage from starting potential by certain slope, and the duration is t2, and slope determines by scanning number of steps, reverse scan time voltage scans preparation voltage from maximum voltage by certain slope, and the duration is t3, ready for scan next time, prepares voltage and starting potential identical or different.
The real-time strategy of adjusting of scanning light source sawtooch sweep voltage: first the starting potential of preparing voltage, forward scan is set, maximum voltage and scanning number of steps; Scanning light source starts after scanning, and the grating signal of the reference path that master control borad is uploaded up data acquisition module is analyzed, and determines whether scanning voltage scope needs real-time adjustment:
Show that being 3 and adjacent two with reference to grating quantity meets predefined scope with reference to the peak between grating if parse the data of reference path, creep and drift that scanning light source is described are little on the impact of system, need not adjust scanning voltage;
Show to be 2 or 1 with reference to grating quantity if parse data, creep and drift that scanning light source is described are very large to systematic influence, make the wavelength band of scanning light source output that skew occur, must adjust the scanning voltage of scanning light source, position by the reference grating that parses is adjusted starting potential and maximum voltage up or down, change scanning light source wavelength of optical signal output area, scan next time, whether the resolution data that again judges reference path meets the requirements, if do not meet, again adjust, until adjust to the right place.
Industrial computer mainly completes wavelength data correction and human interface function, the useful data that master control borad is uploaded is analyzed, according to the one-to-one relationship with reference between grating and temperature, the raster center wavelength of each passage is revised, be shown in real time on display.
Compared with prior art, the utility model has the advantage of: simple 3 of the utility model utilization replaces expensive FP etalon as with reference to light path with reference to grating and 1 temperature sensor, very effectively eliminate the creep of scanning light source own, solve the practical problems in engineering with less cost, there is very strong practicality and novelty.
Accompanying drawing explanation
Fig. 1 is the entire system block diagram of fiber Bragg grating (FBG) demodulator in the utility model embodiment;
Fig. 2 is the block diagram of data acquisition board in the utility model embodiment;
Fig. 3 is the composition frame chart of PLC splitter module in the utility model embodiment;
Fig. 4 is that in the utility model embodiment, light signal passes through three with reference to transmission spectrum schematic diagram after grating.
Embodiment
Below in conjunction with accompanying drawing, embodiment is described in further detail the utility model.
Fiber Bragg grating (FBG) demodulator as shown in Figure 1, it comprises scanning light source 1, splitting ratio is the coupling mechanism 2 of 99:1, PLC splitter module 3, multiple three-dB couplers 4, optical fiber optical grating array 6, reference path 7, data acquisition module 12, master control borad 13, industrial computer 17 and display 18, wherein the power input of scanning light source 1 is connected with master control borad 13, output optical signal under the scanning voltage control that scanning light source 1 is exported at master control borad 13, the light signal that scanning light source 1 is exported enters by the A end of coupling mechanism 2, the B end of coupling mechanism 2 is 99 part in splitting ratio, the C end of coupling mechanism 2 is 1 part in splitting ratio 1, the B termination PLC splitter module 3 of coupling mechanism 2, the C end of coupling mechanism 2 enters reference path 7, each channel output end of PLC splitter module 3 respectively by three-dB coupler 4 laggard enter optical fiber optical grating array 6, the signal that in optical fiber optical grating array 6, fiber grating reflects passes to data acquisition module 12 by connected three-dB coupler 4 successively, the output terminal of reference path 7 is also connected with data acquisition module 12, data acquisition module 12 is connected with master control borad 13, master control borad 13 is connected with industrial computer 17, industrial computer 17 is connected with display 18,
Wherein, described reference path 7 comprise first with reference to grating 8, second with reference to grating 9, the 3rd with reference to grating 10 and temperature sensor 11, temperature sensor 11 is connected with the master control borad CPU of master control borad, above-mentioned three wavelength with reference to grating need to meet certain requirements, could scanning light source be revised and be compensated, to eliminate scanning light source drift, the impact of creep on the measuring precision and stability, simultaneously also can compensated scanning light source non-linear.Fig. 4 is that scanning light source light signal is by the transmission signal example after 3 gratings, if the grating signal wavelength band that system is chosen is between λ 1 to λ 5, require the wavelength scanning range of scanning light source always between λ 1 to λ 5, make demodulating system not omit grating, guarantee the stability of system works, with reference to grating Criterion of Selecting: the first wavelength X 2 with reference to grating and the second wavelength X 3 with reference to grating are near one end λ 1 of system wavelength, the 3rd wavelength X 4 with reference to grating is near the other end λ 5 of system wavelength, and the ratio of λ 4-λ 3 and λ 3-λ 2 at 4:1 between 7:1.In the present embodiment, get λ 2 and λ 3 near λ 1, λ 4 is near λ 5, and the wavelength difference ratio of λ 4-λ 3 wavelength difference and λ 3-λ 2 is 5:1.
For guaranteeing the relative stability of reference path, need 3 and there is uniform temp with reference to grating.This programme is abandoned the implementation of complicated temperature-control circuit, and adopt simple structural design to realize this function, implementation is: first is all arranged in an aluminium block with reference to grating and temperature sensor with reference to grating, the 3rd with reference to grating, second, on this aluminium block, have U-shaped groove, three with reference to grating and temperature sensor mutually near being arranged in this U-shaped groove, in gap in U-shaped groove, heat conductive silica gel is set simultaneously and fixes, on aluminium block, be added with aluminium sheet sealing.Actual test shows, adopts the temperature error between three gratings of this structure to be less than 0.1 degree Celsius, can meet the requirement of industrial occasions.
Described PLC splitter module is made up of nine 1X8PLC shunts 24, wherein the B of coupling mechanism end is connected with the input end of one of them 1X8PLC shunt, and eight output terminals of this 1X8PLC shunt are connected with the input end of eight 1X8PLC shunts that are left respectively.In actual use, can rationally adjust according to number of channels the quantity of 1X8PLC shunt 24, be configured to required passage, here it should be noted that, in the time of 64 passages of combination, because system acquisition system maximum is only supported 64 passages (comprising 1 road reference channel) historical facts or anecdotes border and can only be used 63 passages wherein, 1 is alternate channel, shown in Figure 3.
Described data acquisition module 12 is resolved for the extraction and the centre wavelength that realize grating original signal crest, comprise 16 blocks of data collection plates 121, every blocks of data collection plate comprises 4 path channels, collection plate CPU22 and R232 interface circuit 23, shown in Figure 2, each path channels is equipped with PIN diode 19, automatic gain control circuit 20 and analog to digital converter 21, the analog to digital converter 21 of 4 path channels is connected with collection plate CPU22, collection plate CPU22 is also connected with automatic gain control circuit 20 simultaneously, then collection plate CPU22 is connected with active plate 13 by R232 interface circuit 23.Every blocks of data collection plate can arrange this data acquisition board address by the DIP switch in this data acquisition board, and collection plate CPU controls automatically to the automatic gain control circuit of each path channels.Collection plate CPU adopts the single-chip microcomputer of dominant frequency more than 72MHZ, and analog to digital converter is 12 analog to digital converters of sampling rate more than 1M, shown in Figure 2.
Data acquisition module is adjusted in real time to the enlargement factor of automatic gain control circuit, complete scanning process each time, the amplitude of the fiber grating signal of collection plate CPU to analog to digital converter sampling detects, if maximal value exceedes 0.9 times of analog to digital converter reference value, the corresponding enlargement factor that reduces automatic gain control circuit; If maximal value is less than 0.5 times of analog to digital converter reference value, the enlargement factor of corresponding increase automatic gain control circuit.Adopt the enlargement factor of agc circuit to adjust in real time, be conducive to strengthen versatility and the compatibility of hardware to each passage, can be not inconsistent because of the grating quantity of each passage, distance and length are inconsistent, cause the size of signal different, hardware need to be for the drawback of the independent Design enlargement multiple of each passage.
Described master control borad 13 comprises: amplify and driving circuit 14, D/A converting circuit 15 and master control borad CPU16, master control borad CPU is connected with the input end of D/A converting circuit, the output terminal of D/A converting circuit is connected with the input end of amplification and driving circuit, and the output terminal of amplification and driving circuit is connected with scanning light source.Master control borad CPU adopts the single-chip microcomputer of dominant frequency more than 72MHZ, D/A converting circuit is 16 figure place weighted-voltage D/A converters, master control borad and data acquisition module adopt plate card type connected mode, be specially connector connected mode, communication interface is RS232, master control borad inquire about by timing and interrupt combination mode realize communication more than 1 pair, the automatic identification of the automatic complete paired data acquisition module of master control borad after powering on, identification address is the address of every collection plate DIP switch.
Industrial computer mainly completes wavelength data correction and human interface function.The useful data that master control borad is uploaded is analyzed, and according to the one-to-one relationship with reference between grating and temperature, the raster center wavelength of each passage is revised, and is shown in real time on display.
The principle of work of the fiber Bragg grating (FBG) demodulator that the present embodiment provides is: scanning light source 1 is exported under sawtooch sweep Control of Voltage at master control borad 13, output optical signal, the A end of the coupling mechanism 2 that light signal is 99:1 by splitting ratio enters, the output of B end connects PLC splitter module 3, C end enters reference path 7, the output of the each passage of PLC splitter module 3 by connected three-dB coupler 4 laggard enter optical fiber optical grating array 6, the signal that optical fiber optical grating array 6 reflects passes to PIN diode 19 by port C and the port B of three-dB coupler 4 successively, data acquisition module carries out automatic gain control circuit to comprising three light signals with reference to grating and each path channels, then convert digital signal to by analog to digital converter, carry out Data Analysis by the method for general polynomial matching and to three with reference to grating and each path channels, parse with reference to grating quantity and peak, transmit data with 2Mbps baud rate to master control borad 13 by RS232 mode, master control borad 13 collects after the data that each data acquisition module transmits, judge whether reference path raster data meets the requirements, if be not inconsistent, adjust scanning voltage scope, scan next time, if meet, after assembling according to certain rules together with the temperature data of reference path, transmit data with 115200bps baud rate to PC104 industrial computer 17 by RS232 mode, PC104 industrial computer 17 receives after data according to the one-to-one relationship with reference between grating and temperature, raster center wavelength to each passage is revised, and is shown in real time display 18.
The scanning strategy of described scanning light source 1 is: scanning light source 1 adopts sawtooth voltage to drive, master control borad CPU16 is by controlling D/A converting circuit 15, produce sawtooth wave by amplification and driving circuit 14 again, scanning voltage scope is between 0-50V, complete single pass process comprises three phases: the preparatory stage, forward scan stage and reverse scan stage, time corresponding to each stage is respectively t1, t2 and t3, t2>t3>t1, preparatory stage scanning voltage maintains preparation voltage, duration is t1, act as stabilized light source, for forward scan is prepared, forward scan stage voltage is elevated to maximum voltage from starting potential by certain slope, duration is t2, slope determines by scanning number of steps, when real work, what work is exactly the forward scan time, and forward scan starts, and data acquisition module 12 carries out ADC sampling by certain time interval to each passage grating signal, forward scan finishes, and ADC sampling also finishes, reverse scan time voltage scans preparation voltage from maximum voltage by certain slope, and the duration is t3, ready for scan next time, prepares voltage and starting potential identical or different.
The real-time strategy of adjusting of scanning light source sawtooch sweep voltage: first the starting potential of preparing voltage, forward scan is set, maximum voltage and scanning number of steps; Scanning light source starts after scanning, and the grating signal of the reference path 7 that master control borad 13 is uploaded up data acquisition module 12 is analyzed, and determines whether scanning voltage scope needs real-time adjustment:
Show that being 3 and adjacent two with reference to grating quantity meets predefined scope with reference to the peak between grating if parse the data of reference path, creep and drift that scanning light source is described are little on the impact of system, need not adjust scanning voltage;
Show to be 2 or 1 with reference to grating quantity if parse data, creep and drift that scanning light source is described are very large to systematic influence, make the wavelength band of scanning light source output that skew occur, must adjust the scanning voltage of scanning light source, position by the reference grating that parses is adjusted starting potential and maximum voltage up or down, change scanning light source wavelength of optical signal output area, scan next time, whether the resolution data that again judges reference path meets the requirements, if do not meet, again adjust, until adjust to the right place, the real-time strategy of adjusting of scanning voltage can be adjusted because creep and the drift of scanning light source cause light source output wave band to change, thereby cause passage to lose the situation of grating, thereby improve the stability of system.
The present embodiment adopts scanning light source, substitute FP etalon as with reference to light path with 3 gratings through demarcating simultaneously, by the parsing of reference path wavelength is controlled in real time and is revised the scanning voltage of scanning light source, to eliminate the creep of scanning light source own, lag behind and the impact of drift on Wavelength demodulation.PIN diode detects and adopts amplifying electric circuit with auto-gain-controlling function, for strengthening the detectability of grating signal and the adaptability of each passage, make each by the signal amplitude that receives in optimum range, be unlikely to some large especially by signal, some channel signal is especially little, improves accuracy of detection and stability.(FBG) demodulator scheme passage expansion simultaneously adopts plate card type structure, and expansion is convenient, and maximum can expand to 64 passages.In addition the grating of reference path is carried out to special mounting mode, additionally constant-temperature circuit carries out special control to the temperature of reference path, just can guarantee that in reference path, 3 grating temperatures are relatively consistent, reduces the complexity of system.
Claims (6)
1. a fiber Bragg grating (FBG) demodulator, it is characterized in that: comprise scanning light source (1), splitting ratio is the coupling mechanism (2) of 99:1, PLC splitter module (3), multiple three-dB couplers (4), optical fiber optical grating array (6), reference path (7), data acquisition module (12), master control borad (13), industrial computer (17) and display (18), wherein the power input of scanning light source (1) is connected with master control borad (13), scanning light source (1) is output optical signal under the scanning voltage control of master control borad (13) output, the light signal of scanning light source (1) output enters by the A end of coupling mechanism (2), the B end of coupling mechanism (2) is 99 part in splitting ratio, the C end of coupling mechanism (2) is 1 part in splitting ratio 1, the B termination PLC splitter module (3) of coupling mechanism (2), the C end of coupling mechanism (2) enters reference path (7), each channel output end of PLC splitter module (3) respectively by a three-dB coupler (4) laggard enter optical fiber optical grating array (6), the signal that in optical fiber optical grating array (6), fiber grating reflects passes to data acquisition module (12) by connected three-dB coupler (4) successively, the output terminal of reference path (7) is also connected with data acquisition module (12), data acquisition module (12) is connected with master control borad (13), master control borad (13) is connected with industrial computer (17), industrial computer (17) is connected with display (18),
Wherein, described reference path (7) comprise first with reference to grating (8), second with reference to grating (9), the 3rd with reference to grating (10) and temperature sensor, temperature sensor is connected with master control borad, the first wavelength X 2 with reference to grating (8) and the second wavelength X 3 with reference to grating (9) are near one end of system wavelength, the 3rd wavelength X 4 with reference to grating (10) is near the other end of system wavelength, and the ratio of λ 4-λ 3 and λ 3-λ 2 at 4:1 between 7:1.
2. fiber Bragg grating (FBG) demodulator according to claim 1, it is characterized in that: first is all arranged in an aluminium block with reference to grating (10) and temperature sensor with reference to grating (9), the 3rd with reference to grating (8), second, on this aluminium block, have U-shaped groove, three with reference to grating and temperature sensor mutually near being arranged in this U-shaped groove, in gap in U-shaped groove, heat conductive silica gel is set simultaneously and fixes, on aluminium block, be added with aluminium sheet sealing.
3. fiber Bragg grating (FBG) demodulator according to claim 1, it is characterized in that: described PLC splitter module (3) is made up of nine 1X8PLC shunts (24), wherein the B of coupling mechanism (2) end is connected with the input end of one of them 1X8PLC shunt (24), and eight output terminals of this 1X8PLC shunt (24) are connected with the input end of eight the 1X8PLC shunts (24) that are left respectively.
4. fiber Bragg grating (FBG) demodulator according to claim 1, it is characterized in that: described data acquisition module (12) comprises 16 blocks of data collection plates (121), every blocks of data collection plate (121) has included 4 path channels, a collection plate CPU (22) and R232 interface circuit (23), each path channels is equipped with PIN diode (19), automatic gain control circuit (20) and analog to digital converter (21), the analog to digital converter (21) of 4 path channels is connected with collection plate CPU (22), collection plate CPU (22) is also connected with automatic gain control circuit (20) simultaneously, then collection plate CPU (22) is connected with active plate (13) by R232 interface circuit (23).
5. fiber Bragg grating (FBG) demodulator according to claim 4, it is characterized in that: data acquisition module is adjusted in real time to the enlargement factor of automatic gain control circuit, complete scanning process each time, the amplitude of the fiber grating signal of collection plate CPU (22) to analog to digital converter sampling detects, if maximal value exceedes 0.9 times of analog to digital converter reference value, the corresponding enlargement factor that reduces automatic gain control circuit; If maximal value is less than 0.5 times of analog to digital converter reference value, the enlargement factor of corresponding increase automatic gain control circuit.
6. fiber Bragg grating (FBG) demodulator according to claim 1, it is characterized in that: described master control borad (13) comprising: amplify and driving circuit (14), D/A converting circuit (15) and master control borad CPU (16), master control borad CPU (16) is connected with the input end of D/A converting circuit (15), the output terminal of D/A converting circuit (15) is connected with the input end of amplification and driving circuit (14), and the output terminal of amplification and driving circuit (14) is connected with scanning light source (1).
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320659806.2U CN203704951U (en) | 2013-10-24 | 2013-10-24 | Fiber grating demodulation instrument |
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| Application Number | Priority Date | Filing Date | Title |
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| CN201320659806.2U CN203704951U (en) | 2013-10-24 | 2013-10-24 | Fiber grating demodulation instrument |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103528607A (en) * | 2013-10-24 | 2014-01-22 | 宁波振东光电有限公司 | FBG (fiber bragg grating) interrogator |
| CN107430013A (en) * | 2015-04-02 | 2017-12-01 | 直观外科手术操作公司 | Match somebody with somebody the fiber optic interferometric data of locating tab assembly using reference optical fiber interference data |
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2013
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103528607A (en) * | 2013-10-24 | 2014-01-22 | 宁波振东光电有限公司 | FBG (fiber bragg grating) interrogator |
| CN107430013A (en) * | 2015-04-02 | 2017-12-01 | 直观外科手术操作公司 | Match somebody with somebody the fiber optic interferometric data of locating tab assembly using reference optical fiber interference data |
| US10732075B2 (en) | 2015-04-02 | 2020-08-04 | Intuitive Surgical Operations, Inc. | Registering measured optical fiber interferometric data with reference optical fiber interferometric data |
| US10908047B2 (en) | 2015-04-02 | 2021-02-02 | Intuitive Surgical Operations, Inc. | Registering measured optical fiber interferometric data with reference optical fiber interferometric data |
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