JP4607923B2 - Fiber Bragg grating element reflected light wavelength measurement processing apparatus and processing method - Google Patents

Description

The present invention relates to an apparatus and method for measuring and processing the wavelength of reflected light from an optical fiber Bragg grating element (hereinafter referred to as “FBG”).

  The FBG is formed in the coaxial direction of the optical fiber. When stress is applied to the optical fiber, the formed grating pitch changes. This change depends on physical quantities such as the temperature, strain / displacement, pressure, and vibration of the optical fiber, and the wavelength of the reflected light from the FBG changes according to this change. Therefore, if the center wavelength of reflected light from the FBG or the amount of change in wavelength can be measured with high accuracy, the physical quantity can be measured with high accuracy.

  Hereinafter, a conventional example of the FBG reflected light wavelength measurement processing apparatus will be described with reference to FIG. Output light (hereinafter referred to as “reference light”) from the broadband light source unit 18 is introduced into the optical waveguide unit 19, and the reference light is irradiated to the FBG unit 21 connected to the optical waveguide unit 19 through the optical branching unit 20. Is done.

  The FBG section 21 has a property of reflecting a specific wavelength band, and this wavelength band changes in response to a change in temperature or strain applied to the FBG section 21, and therefore returns through the optical branching section 20. The reflected light is received by the wavelength measuring unit 22 and the change in wavelength is measured. For example, an optical spectrum analyzer or the like is used as the wavelength measuring unit 21 and has a function of receiving reflected light and extracting the wavelength intensity relative to the light intensity with high resolution or extracting it as a data value.

  The above-described conventional system has the following problems.

(1) The reflected light from the FBG has a wavelength bandwidth of about 0.2 to 1 nm, and the spectrum shape is asymmetrical on the left and right. In order to obtain with high accuracy, it is necessary to provide an appropriate calculation interval.

(2) When the intensity of reflected light from the FBG is weak, the amount of light fluctuation due to the influence of light source noise or the like occurs and the spectrum shape is not constant over time. Therefore, since the peak value always fluctuates, the center wavelength obtained every measurement fluctuates and it is difficult to obtain the true center wavelength.

(3) Since it is assumed that a high-resolution wavelength measurement unit is equipped, all necessary wavelength bands are scanned with precise and fine wavelength steps. For this reason, scanning time is inevitably required, and it is difficult to detect a physical quantity that changes at a high speed (hereinafter, dynamic) such as vibration.

(4) Since the light source output does not have a constant light spectrum dependency (wavelength dependency on light intensity), it may appear as an inclination in the flat part of the reflected light and affect the center wavelength measurement.

The present invention has been made especially in response to the above problem (3) , and by acquiring time-series light intensity data corresponding to a physical quantity that changes at high speed such as vibration, the light intensity fluctuation and its fluctuation period are obtained. It is an object of the present invention to provide an apparatus and a method for analyzing the above-mentioned and obtaining a vibration amount such as a displacement amount and acceleration .

In order to solve the above-mentioned problem, the present invention is an invention of a fiber Bragg grating element reflected light wavelength measurement processing apparatus, wherein an optical fiber Bragg grating element is connected by an optical fiber, and a reference light is introduced into the optical fiber to In the apparatus for measuring the wavelength of the reflected light reflected by the optical fiber Bragg grating element, the wavelength tunable filter unit that selectively transmits a specific wavelength band with respect to the reflected light and has inclined sections on both sides; and A wavelength scanning control unit that sets the wavelength tunable filter unit in a fixed state so that the wavelength of the reflected light is included in an inclined section on one side of the wavelength tunable filter unit, and the reflection that is transmitted through the wavelength tunable filter unit A light detection processing unit that detects a change in light intensity by sampling and converts it into fluctuation data corresponding to the light intensity, and the reflection Time-series data processing unit for the variation data of the intensity data of the time series and the time of the vibration amount analysis processing unit that series data by analyzing the determined amount of vibration, comprising a one-side inclined section of said wavelength variable filter unit In the linear linear section, the entire wavelength fluctuation range of the reflected light is included, and the center point of the linear linear section is set to the central wavelength value of the reflected light .

Further, the present invention is an invention of a fiber Bragg grating element reflected light wavelength measurement processing method, wherein an optical fiber Bragg grating element is connected by an optical fiber, a reference light is introduced into the optical fiber, and the optical fiber Bragg grating element is used. In the method of measuring a wavelength of reflected light to be reflected, a wavelength tunable filter unit having inclined sections on both sides of the reflected light selectively transmits a specific wavelength band, and the reflected light is reflected by a wavelength scanning control unit. The wavelength tunable filter unit is set in a fixed state so that the wavelength of the reflected light is included in the inclined section on one side of the wavelength tunable filter unit, and the light detection processing unit transmits the reflected light transmitted through the wavelength tunable filter unit. The change in intensity is detected by sampling and converted into fluctuation data corresponding to the light intensity, and the reflected light intensity is converted by the time-series data processing unit. Of converting the variation data on the data of time series, determine the amount of vibration by analyzing the time-series data by the vibration amount analysis processing unit, wherein the reflected light to a linear straight section on one side inclined section of said wavelength variable filter unit All the wavelength variation ranges are included, and the center point of the linear linear section is set to the center wavelength value of the reflected light .

According to the FBG reflected light wavelength measurement processing apparatus and processing method of the present invention, by obtaining time-series light intensity data corresponding to a physical quantity that changes at high speed such as vibration, the light intensity fluctuation and its fluctuation period are analyzed. The amount of vibration such as displacement and acceleration can be obtained .

  Embodiments of an FBG reflected light wavelength measurement processing apparatus according to the present invention will be described below with reference to the drawings. However, parts common to or similar to those of the prior art or common parts are denoted by common reference numerals, and redundant description is omitted.

[First Embodiment ]
1 and 2 show a first embodiment. This embodiment substantially corresponds to the problems (1) and (2) , and performs static parameter calculation (narrowband filter scan + smoothing differentiation). In FIG. 1, the present embodiment includes a narrowband filter unit 1, a light detection processing unit 2, a wavelength calculation processing unit 3, and a wavelength scanning control unit 4. Further, the wavelength calculation processing unit 3 includes a smoothing differential filter unit 5, a calculation interval setting unit 6, and a weighted average calculation processing unit 32.

  Reflected light from the focused FBG (see FIG. 18) is incident on the narrowband filter unit 1 and is selectively transmitted only at a necessary wavelength. The narrow band filter unit 1 is also called a band pass filter, and is functionally an interference type wavelength filter. The wavelength scanning control unit 4 causes the narrowband filter unit 1 to perform wavelength scanning control of an appropriate wavelength section with respect to the reflected light from the FBG at a constant wavelength interval.

  The reflected light that has passed through the narrow-band filter unit 1 is composed of a photoelectric converter, a signal integrator, an analog-digital converter, and the like (not shown) that convert the reflected light into an electric signal amount corresponding to the intensity. The detection processing unit 2 performs detection processing and outputs the intensity value corresponding to the light intensity of the reflected light to the smoothing differential filter unit 5.

As shown in FIG. 2A, the data output to the smoothing differential filter unit 5 has a shape that approximates the spectrum of the FBG reflected light wavelength. Differential coefficient value data for the light intensity data shown in (b) is obtained. As shown in FIG. 2B, the calculation interval setting unit 6 searches the differential coefficient value data for a region that is equal to or higher than the first threshold value H and a region that is equal to or lower than the second threshold value L that are set in advance. As a region sandwiched between these regions, a section having only a flat portion of the reflection spectrum can be determined as a calculation section. Here, the first threshold value H is set higher than the second threshold value L.
Further, by performing smoothing differentiation, the calculation section of the reflected light data can be set to a flat portion even if the spectrum shape fluctuates because the reflected light is weak.

  The weighted average calculation processing unit 32 extracts the data of the light intensity value and the scanning wavelength value from the appropriate calculation section determined by the calculation section setting unit 6, calculates the weighted average value thereof, and calculates the center wavelength or wavelength of the reflected light. The amount of shift is obtained.

  According to the present embodiment configured as described above, even if the reflected light from the FBG is weak and fluctuates, the center wavelength or the amount of wavelength change can be easily and accurately obtained.

[Second Embodiment ]
Next, FIGS. 3 and 4 show a second embodiment. This embodiment substantially corresponds to the problem (1 ) and performs static parameter calculation (wavelength variable filter scan). In FIG. 3, the present embodiment includes a light detection processing unit 2, a wavelength calculation processing unit 3, a wavelength scanning control unit 4, and a wavelength variable filter unit 7. Further, a maximum point search unit 8 is included in the wavelength calculation processing unit 3.

  The reflected light from the focused FBG is incident on the wavelength tunable filter unit 7 and a necessary wavelength band is selectively transmitted. The wavelength tunable filter unit 7 makes the wavelength variable by changing the angle between the polarizers using the wavelength characteristic of light application (light traveling direction) such as crystal. The wavelength scanning control unit 4 causes the wavelength variable filter unit 8 to perform wavelength scanning control of a suitable wavelength section with respect to the reflected light from the FBG at regular wavelength intervals.

The reflected light that has passed through the wavelength tunable filter unit 7 is detected by the light detection processing unit 2 and output to the maximum point search unit 8. The output data has a symmetrical peak shape as shown in FIG. Since the point where the value of this data is the maximum is the center wavelength, the point is searched by the maximum point search unit 8, and the value of the scanning wavelength for the maximum point searched by the wavelength calculation processing unit 3 is obtained as the center wavelength. is there.
According to this embodiment configured as described above, the center wavelength of the reflected light from the FBG can be easily and accurately obtained.

[Third Embodiment ]
Next, FIGS. 5 and 6 show a third embodiment. This embodiment substantially corresponds to the problems (1) and (2) , and performs static parameter calculation (wavelength variable filter scan-weighted average calculation method). As shown in FIG. 5, the present embodiment has a configuration similar to that of FIG. 3, but omits the maximum point search unit 8 from the wavelength calculation processing unit 3, and extracts the data extraction unit 9 and the first weighted average calculation process. Section 10, calculation section setting section 11, and second weighted average calculation processing section 34.

  The data extraction unit 9 refers to the light intensity data output from the light detection processing unit 2 and searches for a point having the maximum value as shown in FIG. This data is extracted. This extracted data is calculated by the first weighted average calculation processing unit 10 using the weighted average calculation formula shown in FIG. 6B to obtain a temporary wavelength center, and the calculation interval setting unit 11 calculates the temporary wavelength center point. Set the calculation interval symmetrically. Then, the weighted average calculation of the data of the set calculation section is performed by the second weighted average calculation processing unit 34 to obtain the center wavelength or the wavelength change amount of the reflected light.

  According to this configuration, when it is difficult to specify the peak point of the reflected light spectrum because the amount of reflected light is weak, the center point is obtained by weighted averaging the wavelength intensity of the entire spectrum, and the center point is defined as the center wavelength. By doing so, the center wavelength can be obtained. In the case of weighted averaging, if an inappropriate calculation range is set, the center of gravity point cannot be obtained accurately, so by searching for a temporary center point in advance and setting the calculation interval symmetrically from that point, the center wavelength Can be obtained accurately.

[Fourth Embodiment ]
Next, FIGS. 7 and 8 show a fourth embodiment. The present embodiment substantially corresponds to the problems (1) and (2) , and performs static parameter calculation (wavelength variable filter scan-smoothing differential method). As shown in FIG. 7, the present embodiment has a configuration similar to that shown in FIG. 3, except that the maximum point search unit 8 is omitted from the wavelength calculation processing unit 3, and a smoothing differential filter unit 5, a zero level point search unit. 12 is included.

  When the light intensity data shown in FIG. 4B is subjected to the smoothing differentiation process by the smoothing differential filter unit 5, the differential coefficient value data shown in FIG. 8 is obtained. For the obtained derivative value, the zero level point search unit 12 searches for a point that is equal to or higher than a first threshold value H set in advance and a point that is equal to or lower than the second threshold value L. However, the first threshold value H is higher than the second threshold value L. In this way, the zero level point between the threshold values is obtained. Then, the scanning wavelength value for this zero level point is obtained as the center wavelength. Since the point at which the derivative value is zero indicates the peak center, the center wavelength of the reflected light from the FBG can be obtained easily and accurately.

[Fifth Embodiment ]
Next, FIG. 9 shows a fifth embodiment. This embodiment substantially corresponds to the problem (1 ) and performs static parameter calculation (wavelength scanning range). This embodiment has the same configuration as that of any of the second to fourth embodiments, but is particularly restricted in the wavelength scanning section of the wavelength tunable filter unit 7.

  The wavelength of the reflected light from the FBG changes its wavelength value corresponding to a preset physical quantity variation range. In order to measure this amount of wavelength change, the wavelength variable filter unit 7 is scanned the required number of times with respect to the reflected light wavelength, and the center wavelength is obtained from the light intensity data obtained for each measurement. When the wavelength scanning range of the unit 7 is set to be the same as the physical quantity variation range, when the reflected light wavelength is in the vicinity of the maximum and minimum points of the range, only the one-sided data shown in FIG. 4 can be obtained. It is difficult to seek.

  For this reason, in FIG. 9, the half-value width of the wavelength filter of the wavelength tunable filter unit 7 is added to the wavelength fluctuation value of the reflected light corresponding to the fluctuation range of the physical quantity sensed for the FBG of interest, and the half value is obtained. The wavelength scanning section is set symmetrically with respect to the center point of the wavelength variation range of the reflected light. Thereby, even when the reflected light wavelength is in the vicinity of the maximum and minimum points of the measurement range, data up to half the light intensity in the spectrum of FIG. 4 can be acquired. As a result, the center wavelength can be accurately obtained from the maximum point of the light intensity data or by weighted average calculation.

[Sixth Embodiment ]
Next, FIGS. 10 and 11 show a sixth embodiment. The present embodiment substantially corresponds to the problem (3 ) and performs dynamic parameter calculation (converting vibration into light quantity change). In FIG. 10, the present embodiment includes a wavelength tunable filter unit 7, a light detection processing unit 2, a wavelength scanning control unit 4, and a vibration amount analysis processing unit 14. The vibration amount analysis processing unit 14 includes a time series data processing unit 13.

  The reflected light from the focused FBG enters the wavelength tunable filter unit 7 and a necessary wavelength band is selectively transmitted. In the wavelength scanning control unit 4, as shown in FIG. 11A, the wavelength tunable filter unit 7 is fixedly set with respect to the wavelength of the reflected light. The reflected light that has passed through the wavelength tunable filter unit 7 is detected by the light detection processing unit 2 with constant sampling, and is output to the time-series data processing unit 13 as a variation in intensity value corresponding to the variation in light intensity. As stored or recorded. However, when a plurality of FBGs are connected, the sampling rate is not uniform for all FBGs, but is set in advance for each FBG.

  According to these procedures, time-series light intensity data corresponding to a physical quantity that changes at high speed such as vibration can be acquired. The acquired time-series data has information on the fluctuation period and the light intensity displacement amount as shown in FIG. The vibration amount analysis processing unit 14 reads out the time series data stored or recorded by the time series data processing unit 13 and changes the light intensity by, for example, FFT (fast Fourier cosine sine transform) processing which is a typical example of vibration amount analysis. And a fluctuation period such as displacement and acceleration are obtained by analyzing the fluctuation period.

[Seventh Embodiment ]
Next, FIGS. 12 and 13 show a seventh embodiment. This embodiment substantially corresponds to the problem (3 ) and performs dynamic parameter calculation (standby wavelength setting). Although the basic components of this embodiment are the same as those in FIG. 10, the restriction of the wavelength setting condition for the FBG reflected light wavelength of the wavelength tunable filter unit 7 is added.

In FIG. 13, the wavelength scanning control unit 4 sets the central wavelength value of the reflected light from the FBG when there is no load in the measurement field to the center point of the straight section in the one-side inclined section of the wavelength tunable filter section 7. The wavelength variable filter 7 is controlled, and the wavelength variable range of the wavelength variable filter unit 7 or the FBG is set so that the reflected light fluctuation range is entirely included in the linear section in the one-side inclined section of the wavelength variable filter 7 . For example, when the FBG center wavelength is 1550 nm and the wavelength value from the filter center point to the center point of the straight section is 1 nm, the filter center wavelength of the wavelength variable filter unit 7 may be set to 1549 nm or 1551 nm.

The reflected light that has passed through the wavelength tunable filter unit 7 is converted into an intensity fluctuation value corresponding to the amount of change in wavelength by the light detection processing unit 2, and the linear section of the wavelength tunable filter unit 7 is normally as shown in FIG. to from a logarithmic curve, if correction calculation processing intensity variation in the reverse coefficient logarithmic curve, can be obtained a line corresponding intensity variation in wavelength variation. Furthermore, for example, when it is desired to increase the measurement resolution, the wavelength tunable filter unit 7 may be a wide FWHM.

[Eighth Embodiment ]
Next, FIGS. 14 and 15 show an eighth embodiment. The present embodiment substantially corresponds to the problem (3 ) and performs dynamic parameter calculation (converting light quantity variation into wavelength variation). In FIG. 14, the basic components of this embodiment are similar to those of FIG. 10, but in addition to the time series data processing unit 13, the vibration amount analysis processing unit 14 includes a memory unit 15, wavelength conversion processing. Part 16 is included.

  For all the FBG reflected light of interest, the wavelength variable filter unit 7 is scanned as many times as necessary within the wavelength fluctuation range of the reflected light corresponding to the fluctuation range of the physical quantity to be sensed, and the light intensity value and the scanning wavelength value shown in FIG. Data is acquired, and the correlation is converted into a function and stored in the memory unit 15 in advance. As the function, for example, a polynomial shown in FIG. 15 can be applied.

Subsequently, at the time of vibration sensing of the FBG of interest, a corresponding function parameter is called from the related memory unit 15, and using this function, the wavelength conversion processing unit 16 converts the intensity variation data obtained from the light detection processing unit 2 into wavelength variation data. Conversion processing is performed. With these procedures, for example, using a commercially available FBG sensor for vibration measurement, it is possible to directly obtain the vibration displacement amount or acceleration value that has been designed and adjusted in advance with the value of wavelength change.

[Ninth Embodiment ]
Next, a ninth embodiment will be described. The present embodiment substantially corresponds to the problems (1) , (2) , and (3) , and realizes a mixed system (a static / dynamic compatible system).

  In the ninth embodiment, any one configuration of the second to fifth embodiments and any one configuration of the sixth to eighth embodiments are combined and simultaneously used in one measuring apparatus. Contain.

  For example, in the apparatus of the second embodiment (FIGS. 3 and 4), the function of the sixth embodiment (FIGS. 10 and 11), that is, the scanning wavelength is fixed for each focused FBG reflected light. Then, by acquiring the intensity of the reflected light continuously in time, the wavelength fluctuation period of the FBG is calculated, and the wavelength shift amount is calculated by performing wavelength scanning.

  These procedures make it possible to determine both the amount of wavelength shift and its period, and the physical quantities that need to be measured over time, such as vibration measurements and static steady-state measurements. It can be used for both.

[Tenth embodiment ]
Next, FIG. 16 and FIG. 17 show a tenth embodiment. The present embodiment substantially corresponds to the problem (4) , and performs light source correction (corrects light source dependency). In FIG. 16, the present embodiment includes a memory unit 30 and a correction calculation processing unit 17.

  In FIG. 17, the wavelength-dependent light intensity value with respect to the light intensity of the light source and the reciprocal of the wavelength value are converted into a function and stored in advance in the memory unit 30. This functionalization is set for each FBG wavelength variation range, for example, as shown in FIG. When the FBG is measured, the corresponding function parameter is called from the memory unit 30, and the light intensity raw data obtained from the light detection processing unit 2 is corrected and calculated by the correction calculation processing unit 17 using this function. . These procedures make it possible to correct the wavelength dependence of the light intensity of the light source. This light source correction can be applied to any of the first to ninth embodiments.

1 is a block diagram of a first embodiment of an optical fiber Bragg grating element (FBG) reflected light wavelength measurement processing apparatus according to the present invention. It is a figure explaining the effect | action of the FBG reflected light wavelength measurement processing apparatus of FIG. 1, Comprising: (a) is a graph showing the relationship between the wavelength of the output of the optical detection process part 2 of FIG. 1, and relative light intensity, (b) is. The graph which shows typically the relationship between the wavelength of the output of the smoothing differential filter part 5 of FIG. 1, and relative light intensity. The block diagram of 2nd Embodiment of the FBG reflected light wavelength measurement processing apparatus which concerns on this invention. 4A and 4B are diagrams for explaining the operation of the FBG reflected light wavelength measurement processing device in FIG. 3, where FIG. 3A is a graph showing the relationship between the input wavelength of the wavelength tunable filter unit 7 and the relative light intensity, and FIG. 3 is a graph schematically showing the relationship between the output wavelength of the light detection processing unit 3 and the relative light intensity. The block diagram of 3rd Embodiment of the FBG reflected light wavelength measurement processing apparatus which concerns on this invention. It is a figure explaining the effect | action of the FBG reflected light wavelength measurement processing apparatus of FIG. 5, Comprising: (a) is a graph showing the relationship between the wavelength of the output of the optical detection process part 2 of FIG. 5, and relative light intensity, (b) is. 6 shows weighted average calculation formulas in the first and second weighted average calculation processing units 10 and 34 of FIG. The block diagram of 4th Embodiment of the FBG reflected light wavelength measurement processing apparatus which concerns on this invention. 7 is a graph schematically showing the relationship between the wavelength of the output of the smoothing differential filter unit 5 and the relative light intensity. The graph showing the relationship between the wavelength of the input of the wavelength tunable filter part 7 and relative light intensity in 5th Embodiment of the FBG reflected light wavelength measurement processing apparatus which concerns on this invention. The block diagram of 6th Embodiment of the FBG reflected light wavelength measurement processing apparatus which concerns on this invention. FIG. 11 is a diagram for explaining the operation of the FBG reflected light wavelength measurement processing device of FIG. 10, where (a) is a graph showing the relationship between the input wavelength of FIG. 10 and the relative light intensity, and (b) is a diagram. The graph which shows typically the time change of the relative light intensity of the output of ten time series data processing parts. Seventh Embodiment of FBG Reflected Light Wavelength Measurement Processing Device According to the Present Invention A graph showing the relationship between the input wavelength of the wavelength tunable filter section 7 and the relative light intensity. The graph which shows typically the relationship between the wavelength and relative attenuation amount in 7th Embodiment. The block diagram of 8th Embodiment of the FBG reflected light wavelength measurement processing apparatus which concerns on this invention. The graph which shows the correlation of the wavelength and light intensity which are memorize | stored in the memory part 15 in the FBG reflected light wavelength measurement processing apparatus of FIG. The block diagram of the principal part of 10th Embodiment of the FBG reflected light wavelength measurement processing apparatus which concerns on this invention. The graph which shows the wavelength dependence with respect to the light intensity of the light source in the FBG reflected light wavelength measurement processing apparatus of FIG. 16, and a calibration curve. The block diagram of the conventional FBG reflected light wavelength measurement processing apparatus.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Narrow-band filter part, 2 ... Photodetection process part, 3 ... Wavelength calculation process part, 4 ... Wavelength scanning control part, 5 ... Smoothing differential filter part, 6 ... Calculation area setting part, 7 ... Wavelength variable filter part, DESCRIPTION OF SYMBOLS 8 ... Maximum point search part, 9 ... Data extraction part, 10 ... 1st weighted average calculation process part, 11 ... Calculation area setting part, 12 ... Zero level point search part, 13 ... Time series data process part, 14 ... Vibration Quantity analysis processing unit, 15 ... Memory unit, 16 ... Wavelength conversion processing unit, 17 ... Correction calculation processing unit, 18 ... Light source unit, 19 ... Optical waveguide unit, 20 ... Optical branching unit, 21 ... FBG unit, 22 ... Wavelength measurement Reference numeral 30 denotes a memory part, 32 denotes a weighted average calculation processing part, and 34 denotes a second weighted average calculation processing part.

Claims (3)

In an apparatus that connects an optical fiber Bragg grating element with an optical fiber, introduces reference light into the optical fiber, and measures the wavelength of reflected light reflected by the optical fiber Bragg grating element,
A wavelength tunable filter unit that selectively transmits a specific wavelength band with respect to the reflected light and has inclined sections on both sides;
A wavelength scanning control unit that sets the wavelength tunable filter unit in a fixed state so that the wavelength of the reflected light is included in an inclined section on one side of the wavelength tunable filter unit;
A light detection processing unit that detects a change in the intensity of the reflected light that has passed through the wavelength tunable filter unit by sampling and converts it into variation data corresponding to the light intensity; and
A time-series data processing unit that uses the fluctuation data of the reflected light intensity as time-series data;
A vibration amount analysis processing unit for analyzing the time series data to obtain a vibration amount ,
Including all of the wavelength fluctuation range of the reflected light in the linear linear section in the one-side inclined section of the wavelength tunable filter section, and setting the center point of the linear linear section to the central wavelength value of the reflected light, Optical fiber Bragg grating element reflected light wavelength measurement processing device. In the optical fiber Bragg grating element reflected light wavelength measurement processing device according to claim 1,
The wavelength tunable filter unit is scanned within the wavelength variation range of the reflected light, and a memory unit that stores in advance the correlation between the obtained light intensity value and the scanned wavelength value as a function, and measures the wavelength of the reflected light A wavelength conversion processing unit that calls the function from the memory unit and converts the reflected light intensity value data obtained from the time-series data processing unit into wavelength value data by using the function. An optical fiber Bragg grating element reflected light wavelength measurement processing device characterized by that. In the method of measuring the wavelength of reflected light reflected by the optical fiber Bragg grating element by connecting an optical fiber Bragg grating element with an optical fiber, introducing reference light into the optical fiber,
The wavelength tunable filter unit having inclined sections on both sides with respect to the reflected light selectively transmits a specific wavelength band,
The wavelength tunable filter unit is set in a fixed state so that the wavelength of the reflected light is included in the inclined section on one side of the tunable filter unit by the wavelength scanning control unit,
The light detection processing unit detects a change in the intensity of the reflected light transmitted through the wavelength tunable filter unit by sampling and converts it into fluctuation data corresponding to the light intensity,
The time-series data processing unit converts the reflected light intensity fluctuation data into time-series data, the vibration amount analysis processing unit analyzes the time-series data to determine the vibration amount ,
Including all of the wavelength fluctuation range of the reflected light in the linear linear section in the one-side inclined section of the wavelength tunable filter section, and setting the center point of the linear linear section to the central wavelength value of the reflected light, Optical fiber Bragg grating element reflected light wavelength measurement processing method.

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