JP2005227130A - Optical spectrum analyzer and multichannel measurement apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical spectrum analyzer and a multichannel measurement apparatus, using the same allowing wavelength measurement for a plurality of light rays at a high speed and with high accuracy. <P>SOLUTION: A plurality of light rays to be measured Pb from an optical sensor section 21 are received by a plurality of entrance sections 31 of the optical spectrum analyzer 30 and are allowed to enter with their optical axes being aligned parallel to each other and perpendicular to the diffraction grooves of a diffraction grating 32. Diffracted light rays, emitted from the diffraction grating 32, are received by a reflecting plate 40 of a reflector 35 to be reflected toward the diffraction grating 32. Diffracted light rays, emitted from the diffraction grating at a predetermined angle, are received by a plurality of photoelectric convertors 50, respectively. A drive signal generator 55 provides the reflector 35 with an electrical signal, having a frequency corresponding to the natural frequency of a portion, consisting of a shaft section 38 and the reflecting plate 40, to provide the portion with reciprocal rotational drive with the natural frequency and sweeps the wavelength of light received by each photoelectric convertor 50 within a predetermined wavelength range. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for making it possible to measure wavelength changes of a plurality of lights at high speed.

  Along with the improvement in performance and cost of optical instruments, methods for optically measuring various phenomena have been actively researched and put into practical use.

  For example, various strain-related measurement methods have been proposed in which an optical fiber that is not easily affected by lightning, noise, or the like is used as a sensor from a conventional method that uses a strain gauge as a strain-electric conversion element as a sensor.

  As an optical fiber used as such a strain sensor, a fiber Bragg grating (hereinafter referred to as FBG) is known.

  The FBG is obtained by periodically changing the refractive index of a core portion of a predetermined length range of an optical fiber at regular intervals. When light is incident on one end side of the FBG, a specific wavelength (Bragg wavelength) of the incident light is used. Only light of the other wavelength is reflected, and light of other wavelengths is transmitted.

  And this Bragg wavelength changes according to the distortion (compression, expansion | extension) of the axial direction which the part into which a refractive index changes periodically with a fixed interval receives.

  Therefore, it is possible to measure the external force applied to the FBG by measuring the wavelength of the light that is incident on one end of the FBG and is reflected on the one end side.

  In measurement of an earthquake or the like, it is necessary to measure the acceleration received by an object three-dimensionally. When this is measured using the FBG, the reference object is moved in the vertical direction, the front-rear direction, and the left-right direction using a plurality of FBGs. The change of each Bragg wavelength accompanying the extension change of each FBG generated when the reference object moves due to the occurrence of an earthquake is examined, and the acceleration in each direction is examined from the wavelength change.

  In addition, the technology for supporting a reference object with a plurality of FBGs and measuring the Bragg wavelength of light reflected by each FBG with the wavelength measuring means and analyzing the earthquake based on the measurement results is as follows. Patent Document 1 discloses this.

JP 2001-281347 A

  However, in the case of performing wavelength measurement of light reflected by a plurality of FBGs using independent wavelength measurement means as in Patent Document 1, the larger the number of FBGs, the larger the apparatus and the higher the cost.

  In particular, when measuring a natural phenomenon such as an earthquake as described above, it is necessary to provide a large number of measurement points, resulting in an enormous system cost.

  In order to solve this problem, Patent Document 1 discloses that a plurality of FBGs are connected in series, and the wavelength of the light reflected from each FBG with respect to the light incident from one end thereof is one wavelength measuring unit. In this configuration, it is necessary to select in advance so that the Bragg wavelengths of the FBGs do not overlap, and various types of FBGs are required. Must be strict.

  In addition, a wavelength measurement means that requires a very wide wavelength measurement range is required, but measuring instruments with a wide wavelength measurement range generally have either low accuracy or low measurement speed. High-precision and high-speed measurement could not be expected.

  The present invention has been made in view of such a problem, and provides an optical spectrum analyzer capable of measuring a plurality of wavelengths of light at high speed and with high accuracy, and a multichannel measurement apparatus using the same. It is aimed.

In order to achieve the object, an optical spectrum analyzer according to claim 1 of the present invention comprises:
A diffraction grating (32);
A plurality of incident portions (31) that allow a plurality of light beams to be measured to be incident in directions parallel to each other and perpendicular to the diffraction grooves of the diffraction grating;
A fixed substrate (36, 37), a shaft portion (38, 39) extending from the edge of the fixed substrate with a predetermined width and having a predetermined length and capable of being twisted and deformed along the length direction; A reflection plate (40) connected to the tip at its own edge and rotatably supported with respect to the fixed substrate, and provided with a reflection surface for reflecting diffracted light from the diffraction grating on one surface side; A reflector (35) that receives the diffracted light emitted from the diffraction grating with respect to the plurality of light beams to be measured incident from the plurality of incident portions, and reflects the diffracted light to the diffraction grating;
Aligned along the length direction of the diffraction grooves of the diffraction grating, each of the reflected light emitted from the reflector receives each diffracted light emitted from the diffraction grating at a predetermined angle and converts it into an electrical signal. A plurality of photoelectric converters (50);
A force is applied to the reflecting plate by an electric signal having a frequency corresponding to the natural frequency of the portion composed of the shaft portion and the reflecting plate of the reflector, and the reflecting plate is rotated back and forth at the natural frequency or a frequency close thereto. And reflector driving means (45, 46, 47, 55) for sweeping the wavelength of light received by the plurality of photoelectric converters within a predetermined wavelength range.

A multi-channel measuring device according to claim 2 of the present invention is
An optical sensor unit (21) for emitting light whose wavelength or intensity changes according to a phenomenon change at a measurement point in parallel for a plurality of measurement points;
A spectrum measuring section (30) for receiving a plurality of lights emitted from the optical sensor section as light to be measured and measuring spectrum characteristics thereof;
In a multi-channel measurement apparatus having an analysis unit (60) for analyzing a phenomenon change at each measurement point based on a spectrum change at each measurement point measured by the spectrum measurement unit,
The spectrum measuring unit is configured by the optical spectrum analyzer according to claim 1.

A multi-channel measuring device according to claim 3 of the present invention is the multi-channel measuring device according to claim 2,
The optical sensor unit is
A light source (22);
A plurality of fiber Bragg gratings (23) arranged at the plurality of measurement points, respectively, for receiving light from the light source and emitting a plurality of lights whose wavelengths change in accordance with changes in strain received at the respective measurement points; It is characterized by having.

A multi-channel measuring device according to claim 4 of the present invention is the multi-channel measuring device according to claim 2,
The optical sensor unit is
A light source (22);
A plurality of light-receiving units that pass through the spaces of the plurality of measurement points from the light source, receive a plurality of lights whose absorption wavelengths or absorption amounts change according to changes in gas in the spaces, and emit the light to the spectrum measurement unit. (28).

  With this configuration, the optical spectrum analyzer of the present invention can simultaneously measure the spectrum characteristics of a plurality of light incident in parallel at high speed.

  In addition, a multi-channel measurement apparatus using this optical spectrum analyzer as a spectrum measurement unit can simultaneously measure changes in phenomena at each measurement point at a high speed, and can be configured at low cost.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a configuration of a multi-channel measuring apparatus 20 of the present invention that can be applied to a seismometer or the like.

  The multi-channel measuring device 20 includes an optical sensor unit 21 that emits light whose wavelength changes in response to a phenomenon change at a measurement point in parallel at a plurality of measurement points, and a spectrum of the plurality of lights emitted from the optical sensor unit 21. The optical spectrum analyzer 30 as a spectrum measuring unit for measuring the measurement point, and the analysis unit 60 for analyzing the phenomenon change at the measurement point based on the spectrum for each measurement point measured by the optical spectrum analyzer 30.

  The optical sensor unit 21 supports, for example, a reference object (not shown) like the above-described seismometer, and a plurality of FBGs 23 (1) to 23 (n) receiving light from the light source 22 respond to distortion caused by external force. Thus, it is configured to emit light whose wavelength changes.

  That is, as shown in FIG. 1, the light emitted from the light source 22 is branched into n fiber optical paths by optical couplers 24 (1) to 24 (n), and the branched lights Pa (1) to Pa ( n) is incident on one end of each of the FBGs 23 (1) to 23 (n) through the optical couplers 25 (1) to 25 (n), and the Bragg wavelength reflected by the FBGs 23 (1) to 23 (n). Lights Pb (1) to Pb (n) are incident on the incident portions 31 (1) to 31 (n) of the optical spectrum analyzer 30 from the optical couplers 25 (1) to 25 (n) through the fiber optical path.

  Here, the Bragg wavelength in the undistorted state of each of the FBGs 23 (1) to 23 (n) is equal to λ0, and the band of the light emitted from the light source 22 is that of each of the FBGs 23 (1) to 23 (n). It is assumed that the range of change of the Bragg wavelength is covered.

  As shown in FIG. 2, the plurality of incident portions 31 (1) to 31 (n) of the optical spectrum analyzer 30 are supported by a support member 30b provided on the flat upper surface of the base 30a. It is supported so as to be lined up vertically.

  Each incident portion 31 (1) to 31 (n) includes a collimator lens, and the beam width of the light Pb (1) to Pb (n) incident from each optical coupler 25 (1) to 25 (n) is substantially constant. Grating (collimated light) Pc (1) to Pc (n), the optical axis of which is parallel to the upper surface of the base 30a and vertically aligned, and the diffraction grating installed upright on the base 30a The light is incident at a predetermined angle on one surface (diffraction surface) 32a.

  On one surface 32a of the diffraction grating 32, diffraction grooves orthogonal to the upper surface of the base 30a are provided at predetermined intervals, and light of each wavelength included in the incident light Pc (1) to Pc (n). Each component is emitted at a diffraction angle corresponding to the wavelength.

  The diffracted lights Pd (1) to Pd (n) emitted from the diffraction grating 32 with respect to the incident lights Pc (1) to Pc (n) are incident on the reflector 35 erected on the base 30a.

  As shown in FIGS. 2 and 3, the reflector 35 includes a pair of fixed substrates 36 and 37 that are horizontally long and arranged in parallel to each other, and the center of the long side edge of the fixed substrates 36 and 37. A pair of shaft portions 38 and 39 that extend in a direction orthogonal to the fixed substrates 36 and 37 with a predetermined width and a predetermined length and can be twisted and deformed along the length direction, and one long side in a horizontally long rectangle The reflector 40 is connected to the tip of the shaft 38 at the center of the edge and connected to the tip of the shaft 38 at the center of the other long side edge.

  Since the central portion of the reflector 40 is supported by the shaft portions 38 and 39 that can be torsionally deformed, the reflector 40 can rotate with respect to the fixed substrates 36 and 37 with the line connecting the shaft portions 38 and 39 as the central axis. it can. Further, the natural frequency f0 of the portion composed of the shaft portions 38 and 39 and the reflecting plate 40 is determined by the shape and mass of the reflecting plate 40 itself and the spring constant of the shaft portions 38 and 39.

  In addition, a reflection surface 41 that reflects light with high reflectance is formed on one surface side of the reflection plate 40. The reflection surface 41 may be formed by mirror-finishing the reflection plate 40 itself, or may be formed by vapor deposition or adhesion of a highly reflective film (not shown). The reflector 35 is integrally cut out from a thin semiconductor substrate by etching or the like, and has high conductivity by metal film vapor deposition.

  The reflector 35 is supported on one surface side of the support substrate 45 fixed in an upright state on the base 30a.

  The support substrate 45 is made of an insulating material, and support bases 45a and 45b projecting forward are formed on the upper and lower portions on one side, and the fixed substrates 36 and 37 of the reflector 35 are formed on the upper and lower sides. Are fixed in contact with the support bases 45a and 45b.

  In addition, electrode plates 46 and 47 that are opposed to both ends of the reflection plate 40 of the reflector 35 are formed in patterns at both ends of the central portion on the one surface side of the support substrate 45.

  The electrode plates 46 and 47 constitute the reflector driving means of the embodiment together with the driving signal generator 55 described later, and electrostatic force is alternately and periodically applied to both ends of the reflecting plate 40. The reflector 40 is reciprocally rotated around a line connecting the shaft portions 38 and 39. The rotational axis of the reflecting plate 40 is set to be parallel to the diffraction grooves of the diffraction grating 32.

  As shown in FIGS. 1 and 2, the reflector 35 configured in this manner receives each diffracted light Pd (1) to Pd (n) from the diffraction grating 32 by the reflecting surface 41 of the reflecting plate 40. Then, the reflected lights Pe (1) to Pe (n) are incident again on the diffraction grating 32 and are diffracted.

  The photoelectric converters 50 (1) to 50 (n) are supported in a vertical row by a support member 30c erected on the upper surface of the base 30a, and are diffraction gratings with respect to the reflected light Pe (1) to Pe (n). Of the diffracted light emitted by 32, the diffracted lights Pf (1) to Pf (n) emitted at a predetermined angle with respect to the diffraction surface 32a of the diffraction grating 32 are respectively received, and the voltage corresponding to the intensity of the light is received. The light reception signals E (1) to E (n) are output.

  In the optical spectrum analyzer 30 having such an optical arrangement, the wavelengths of the diffracted lights Pf (1) to Pf (n) received by the plurality of photoelectric converters 50 (1) to 50 (n) are the diffraction surfaces of the diffraction grating 32. It changes according to the angle of the reflector 40 of the reflector 35 with respect to 32a.

  On the other hand, the drive signal generator 55 corresponds to the natural frequency f0 with respect to the electrode plates 46 and 47 with reference to the potential of the reflector 35 as shown in FIGS. The drive signals Da and Db having a frequency (natural frequency f0 or a frequency in the vicinity thereof) and having a phase shifted by 180 ° are applied between the electrode plate 46 and one end side of the reflection plate 40 and the electrode plate 47. An electrostatic force (attracting force) is alternately and periodically applied to the reflecting plate 40, and the reflecting plate 40 is reciprocally rotated within a predetermined angle range at a natural frequency f0 or a frequency in the vicinity thereof.

  This angle range determines the wavelength range λa to λb of the diffracted light received by each of the photoelectric converters 50 (1) to 50 (n). The wavelength range (wavelength sweep range) λa to λb is determined by the FBG 23 ( 1) to 23 (n) are set so as to cover the change range of the Bragg wavelength.

  4 shows a case where the two drive signals Da and Db are rectangular waves with a duty ratio of 50%, the duty ratio of both signals may be 50% or less, and the waveform is also a rectangular wave. It is not limited to sine waves, triangular waves, and the like.

  In addition, the drive signal generator 55 outputs wavelength data D (λ) corresponding to the wavelength swept by the drive signals Da and Dd to the spectrum data storage means 57 described later.

  On the other hand, the signals E (1) to E (n) of the photoelectric converters 50 (1) to 50 (n) are converted into digital signal sequences by the A / D converters 56 (1) to 56 (n), respectively. It is converted and input to the spectrum data storage means 57.

  The spectrum data storage means 57 converts the received light signals E (1) to E (n) converted into digital values by the A / D converters 56 (1) to 56 (n) into the respective incident lights Pb (1) to Pb. (N) spectrum data is stored in an internal memory (not shown) in association with the wavelength data D (λ).

  The analysis unit 60 analyzes the spectrum data of each incident light Pb (1) to Pb (n) stored in the spectrum data storage unit 57, and sets the wavelength (Bragg wavelength) at which the intensity of the spectrum reaches a peak, for example, 1 Each of the sweeps is obtained, and the wavelength change Δλ is obtained in time series.

  Then, from this wavelength change Δλ, the strains H (1) to H (n) of the FBGs 23 (1) to 23 (n) are calculated, and various analyzes relating to the earthquake are performed based on the strain data. Display and output analysis results, etc., and perform processing such as alarm generation if necessary.

  In the optical spectrum analyzer 30 of the multi-channel measuring apparatus 20 configured as described above, the reflector 35 is extended from the pair of fixed substrates 36 and 37 and a predetermined length from the edge thereof with a predetermined width, and the length direction thereof. The shaft portions 38 and 39 that can be twisted and deformed along the edges of the shaft portions 38 and 39 are connected to the ends of the shaft portions 38 and 39, and are formed in a symmetrical shape with respect to the shaft portions 38 and 39. 41, and a force is applied to the reflector 40 by an electrical signal having a frequency corresponding to the natural frequency f0 of the portion formed by the shaft portions 38 and 39 of the reflector 35 and the reflector 40. The reflecting plate 40 is reciprocally rotated at the natural frequency f0 or a frequency in the vicinity thereof.

  For this reason, the reflector 40 can be reciprocally rotated at a high speed with a small amount of electrical energy, and the center of rotation is inside the reflector 40 (in this case, the central portion). The amount of change in the reflection angle of incident light on the reflecting surface 41 of the reflecting plate 40 becomes the largest, and the wavelength sweeping range can be greatly widened.

  The spring constants of the shaft portions 38 and 39 are determined by the length, width, thickness, and material of the shaft portions 38 and 39, and the natural frequency f0 is determined by the spring constant and the shape, thickness, material, and the like of the reflector 40. By selecting these parameters, the natural frequency f0 can be set within a range of several hundred Hz to several tens KHz.

  As described above, the optical spectrum analyzer 30 can simultaneously acquire the spectrum data for a plurality of incident lights incident simultaneously, so that the multichannel measuring device 20 including the optical sensor unit 21 can be configured in a small size. If the phenomenon is relatively slow, such as an earthquake, almost real-time measurement is possible.

  Therefore, the light Pb (1) to Pb (reflected from the FBGs 23 (1) to 23 (n) as described above with respect to the plurality of incident portions 31 (1) to 31 (n) of the optical spectrum analyzer 30. By making n) incident, it is possible to accurately analyze the strain received by each of the FBGs 23 (1) to 23 (n).

  For example, when spectrum data as shown in FIG. 5 is obtained in the wavelength range λa to λb by the first sweep when a steady force is applied to each of the FBGs 23 (1) to 23 (n), the analysis is performed. The unit 60 obtains wavelengths (Bragg wavelengths) λ (1, 1) to λ (n, 1) at which the intensity of the spectrum data peaks.

  Then, the wavelength difference Δλ between the undistorted Bragg wavelength λ0 and the Bragg wavelengths λ (1,1) to λ (n, 1) in the initial state is obtained as follows.

Δλ (1,1) = λ (1,1) −λ0
Δλ (2,1) = λ (2,1) −λ0
Δλ (3,1) = λ (3,1) −λ0
......
Δλ (n, 1) = λ (n, 1) −λ0

  Each of these obtained wavelength differences is due to axial distortion that is constantly applied to each of the FBGs 23 (1) to 23 (n), and the distortion H can be obtained by the following calculation.

H (i, j) = Δλ (i, j) / [λ0 · (1-p)]
Here, i is a number that designates each FBG and is a value between 1 and n, j is a value that represents the number of times Bragg wavelength is detected (for example, the number of sweeps) for one FBG, and p is a Poisson's ratio (component of distortion tensor) Constant).

  The analysis unit 60 obtains distortions H (1,1) to H (n, 1) for the obtained first wavelength differences Δλ (1,1) to Δλ (n, 1), which are not shown in the drawing. Store in the memory.

  For example, when spectrum data as shown by the dotted line in FIG. 5 is obtained in the next sweep, Bragg wavelengths λ (1, 2) to λ (n, 2) are obtained from each spectrum data in the same manner as described above. Wavelength changes Δλ (1,2) to Δλ (n, 2) from the undistorted Bragg wavelength λ0 are obtained, and distortions H (1,2) of the FBGs 23 (1) to 23 (n) are determined based on the wavelength changes. ) To H (n, 2) are calculated.

  Thereafter, the same processing is performed every time the wavelength sweep is performed by the optical spectrum analyzer 30 (or every plural wavelength sweeps), so that the distortion H of each of the FBGs 23 (1) to 23 (n) as shown in FIG. A change with time can be obtained.

  As shown in FIG. 6, in a certain time range Ti, the distortions of the FBGs 23 (1) to 23 (n) change greatly and violently, and it is possible to recognize the occurrence of an earthquake from this state, It is possible to analyze the characteristics of earthquakes generated from their magnitude, change period, phase difference of each change, and so on.

  The above-described multi-channel measuring device 20 has been subjected to a distortion due to an earthquake or the like. However, for example, when measuring a volcanic gas or the state of air in a tunnel or the like, the wavelength absorption action of the gas is reduced. Can be used.

In that case, an optical sensor unit 21 'may be configured as shown in FIG.
The optical sensor unit 21 ′ of the multi-channel measuring device 20 ′ shown in FIG. 7 converts the emitted light Pa (1) to Pa (n) from the light sources 22 (1) to 22 (n) into the space K ( 1) to K (n), respectively, and each passing light Pb (1) to Pb (n) is received at one end side of the light receiving sections 28 (1) to 28 (n), respectively. It guide | induces to incident part 31 (1) -31 (n).

  In this case, each passing light Pb (1) to Pb (n) exists in each space from the emitted light of each light source 22 (1) to 22 (n), as shown in FIG. 8, for example. The wavelength component peculiar to gas is absorbed.

  Therefore, by obtaining the spectrum data for each passing light Pb (1) to Pb (n) in the same manner as described above by the optical spectrum analyzer 30, and obtaining the wavelength (dip wavelength) that is greatly attenuated by absorption in the spectrum, The gas components and amounts contained in the spaces K (1) to K (n) can be grasped.

  Further, as indicated by a dotted line A in FIG. 8, when the dip changes deeply at the absorption wavelength of a specific gas, it can be seen that the amount of gas at that wavelength has increased, and is indicated by a dotted line B. Thus, if a dip occurs at a wavelength that has not been dipped until then, it can be seen that a new type of gas has appeared.

  In addition, since the absorption wavelength due to gas varies depending on temperature, pressure, and the like, the presence or absence of a change in temperature or pressure can be determined by examining the change in dip wavelength.

  Here, a plurality of light sources are used assuming that measurement points are separated from each other. However, when each measurement point is close, a common light source is used in the same manner as the optical sensor unit 21 of the multichannel measurement device 20. And a plurality of optical couplers. Conversely, in the embodiment of the earthquake measurement described above, a plurality of light sources may be used as in the embodiment for gas measurement.

  Further, in the optical spectrum analyzer 30 used in the multi-channel measuring device 20 described above, the reflector 35 is made of a material having high conductivity. However, when the reflector 35 is made of a material having low conductivity, Electrode plates opposed to the electrode plates 46 and 47 are provided on both sides (or the entire surface) of the reflection plate 40 opposite to the reflection surface 41, respectively, and electrode plates are also provided on the back side of the fixed substrates 36 and 37. The electrode plates are connected by a pattern or the like. Then, on the surfaces of the support bases 45a and 45b of the support substrate 45, an electrode plate that comes into contact with the electrode plates on the back side of the fixed substrates 36 and 37 is patterned, and at least one of them is used as a reference potential line to generate the drive signal described above What is necessary is just to connect to the device 55.

  Further, the fixed substrates may be formed in a U-shaped frame or a rectangular frame shape by connecting one end side or both ends of the fixed substrates 36 and 37. Moreover, the shape of the reflecting plate 40 is also arbitrary, and may be a circle, an ellipse, an oval, a rhombus, a square, a polygon, or the like in addition to the above-described horizontally long rectangle.

  Further, in order to reduce air resistance during high-speed reciprocating rotation, a large hole or a large number of small holes may be provided inside the reflector plate 40.

  Further, in the optical spectrum analyzer 30 described above, the two electrode plates 46 and 47 facing each other at both ends of the reflection plate 40 of the reflector 35 are provided, but only by one electrode plate (for example, the electrode plate 46). An electrostatic force may be applied.

  Moreover, also about a drive system, you may rotate the reflecting plate 40 reciprocatingly with an electromagnetic force other than the above-mentioned electrostatic force.

  In this case, for example, a coil is used instead of the electrode plates 46 and 47 described above, and a magnetic body or a coil is provided at both ends of the reflector 40, and an attractive force due to a magnetic field generated between the coils or between the coil and the magnetic body. And the reflecting plate 40 is reciprocated by the repulsive force.

  Further, as described above, in addition to the method of directly applying an electrostatic force or electromagnetic force to the reflector 40, the natural frequency f0 by an ultrasonic vibrator or the like or a vibration in the vicinity thereof is applied to the entire reflector 35, It is also possible to transmit the vibration to the reflecting plate 40 and rotate it back and forth. In this case, the vibration can be efficiently transmitted to the reflection plate 40 by providing the vibrator on the back side of the support substrate 45 and the support bases 45a and 45b.

  In the optical spectrum analyzer 30 described above, the diffracted light Pf (i) emitted from the diffraction grating 32 is directly received by the photoelectric converter 50 (i), but each diffracted light Pf ( i) is condensed by a condensing lens and incident on each photoelectric converter 50 (i), or each diffracted light Pf (i) emitted from the diffraction grating 32 is converted into each photoelectric via a slit. A structure for entering the converter 50 (i) may be used, and a condensing lens and a slit may be used in combination.

  Further, in the above-described multi-channel measuring devices 20, 20 ′, earthquakes, gases, and the like are measured objects. However, the present invention is similarly applied to measuring objects that can detect phenomenon changes as light wavelength changes and intensity changes. it can.

Overall configuration diagram of a multi-channel measuring apparatus to which the present invention is applied Configuration diagram of optical system of optical spectrum analyzer of embodiment An exploded perspective view of the main part of the optical spectrum analyzer Drive signal diagram Spectrum diagram for explaining the operation of the embodiment Diagram showing changes in strain due to earthquakes, etc. Overall configuration of multi-channel measuring device for gas measurement Spectrum diagram for gas measurement

Explanation of symbols

  20, 20 '.... multi-channel measuring device, 21, 21' .. optical sensor, 22..light source, 23..FBG, 24, 25..optical coupler, 28..light receiving unit, 30..optical spectrum Analyzer 31 ... Incident part 32 ... Diffraction grating 35 ... Reflector 36, 37 ... Fixed substrate 38, 39 ... Shaft part 40 ... Reflector plate 41 ... Reflecting surface 45 ... ... support substrate, 46, 47 ... electrode plate, 50 ... photoelectric converter, 55 ... drive signal generator, 56 ... A / D converter, 57 ... spectrum data storage means, 60 ... analysis unit

Claims (4)

A diffraction grating (32);
A plurality of incident portions (31) that allow a plurality of light beams to be measured to be incident in directions parallel to each other and perpendicular to the diffraction grooves of the diffraction grating;
A fixed substrate (36, 37), a shaft portion (38, 39) extending from the edge of the fixed substrate with a predetermined width and having a predetermined length and capable of being twisted and deformed along the length direction; A reflection plate (40) connected to the tip at its own edge and rotatably supported with respect to the fixed substrate, and provided with a reflection surface for reflecting diffracted light from the diffraction grating on one surface side; A reflector (35) that receives the diffracted light emitted from the diffraction grating with respect to the plurality of light beams to be measured incident from the plurality of incident portions, and reflects the diffracted light to the diffraction grating;
Aligned along the length direction of the diffraction grooves of the diffraction grating, each of the reflected light emitted from the reflector receives each diffracted light emitted from the diffraction grating at a predetermined angle and converts it into an electrical signal. A plurality of photoelectric converters (50);
A force is applied to the reflecting plate by an electric signal having a frequency corresponding to the natural frequency of the portion composed of the shaft portion and the reflecting plate of the reflector, and the reflecting plate is rotated back and forth at the natural frequency or a frequency close thereto. And a reflector driving means (45, 46, 47, 55) for sweeping the wavelength of light received by the plurality of photoelectric converters within a predetermined wavelength range. An optical sensor unit (21) for emitting light whose wavelength or intensity changes according to a phenomenon change at a measurement point in parallel for a plurality of measurement points;
A spectrum measuring section (30) for receiving a plurality of lights emitted from the optical sensor section as light to be measured and measuring spectrum characteristics thereof;
In a multi-channel measurement apparatus having an analysis unit (60) for analyzing a phenomenon change at each measurement point based on a spectrum change at each measurement point measured by the spectrum measurement unit,
The multi-channel measurement apparatus, wherein the spectrum measurement unit is configured by the optical spectrum analyzer according to claim 1. The optical sensor unit is
A light source (22);
A plurality of fiber Bragg gratings (23) arranged at the plurality of measurement points, respectively, for receiving light from the light source and emitting a plurality of lights whose wavelengths change in accordance with changes in strain received at the respective measurement points; The multi-channel measuring apparatus according to claim 2, wherein The optical sensor unit is
A light source (22);
A plurality of light-receiving units that pass through the spaces of the plurality of measurement points from the light source, receive a plurality of lights whose absorption wavelengths or absorption amounts change according to changes in gas in the spaces, and emit the light to the spectrum measurement unit. The multi-channel measuring device according to claim 2, wherein:

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