JP2005156178A - Pressure evaluation method and optical waveguide type pressure sensor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical waveguide type pressure sensor that has a small amount of influence to a temperature change, dispenses with hysteresis correction, can detect pressure with high sensitivity, and can be handled easily. <P>SOLUTION: The optical waveguide type pressure sensor comprises: a hard coat film 5 in contact with the surface of a member to be inspected; an elastic waveguide 6 formed at least at one portion of the optical fiber 3; and a detection section for detecting the optical change in light entering/exiting the optical fiber 3. The elastic waveguide 6 is elastically deformed by pressure on the surface of the member to be inspected propagated via the hard coat film 5. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is a fluid transport pipe and pressure vessel used in chemical plants, pharmaceutical plants, etc., as well as pipe wall pressure detectors such as pipes for daily gas and water pipes, and pressure sensors for measuring water pressure and gas pressure. The present invention relates to a suitably used optical waveguide pressure sensor and pressure evaluation method.

  Conventionally, a strain gauge has been used as a tube wall pressure detector for detecting a pressure acting on a tube wall such as a fluid transport tube or a pressure vessel. In the fluid transport pipe, a force acts on the pipe wall due to a pressure difference between the inside and outside of the transport liquid, and the pipe expands or contracts. The steam pipe pressure detector is a method of measuring a change amount of expansion or contraction of a pipe with a strain gauge.

  The measurement method using the strain gauge is a method in which the strain gauge is fixed to the outer wall of the fluid transport pipe by adhesion, and the length of the gauge changes due to the change in the length of the outer circumference of the pipe accompanying expansion and contraction of the fluid transport pipe. This is a method of changing the resistance value of the distortion.

  In this method, the change in resistance at this time is measured using a resistance measuring circuit such as a Wheatstone bridge or the direct current four-terminal method, so that the pressure acting on the pipe wall of the fluid transport pipe is indirectly known.

  As another pressure evaluation method, there is a method using a dielectric. In this method, a method is generally used in which the strain generated when pressure is applied is converted into voltage as electrostriction and the pressure is measured from the voltage value. Further, the pressure can be similarly evaluated from a change in capacitance due to a change in the dielectric constant of the dielectric.

On the other hand, a method using the magnetostrictive effect of a magnetic material is also known. In this method, a Hall probe is attached to the surface of a magnetic material, and the magnetic flux density generated by the pressure applied to the magnetic material is measured to evaluate the pressure. For example, the magnetic flux generated by magnetostriction is evaluated using a giant magnetostrictive material such as Fe ₂ Dy.

In addition, a method using an optical fiber and a method using an optical waveguide are also disclosed (see Patent Documents 1 and 2).
Japanese Patent Application No. 5-61489 Japanese Patent Application No. 5-40171

  However, in the conventional measurement method using a strain gauge using a resistance change, since the resistance value changes with temperature, a temperature correction is required, and particularly when the strain gauge has a temperature distribution as a whole, There is a fundamental problem that the temperature cannot be corrected.

  In addition, as a problem when measuring pressure using the above-mentioned dielectric characteristics, the change in dielectric characteristics due to temperature is large, and the dielectric constant and electrostriction characteristics also vary greatly between room temperature and about 100 ° C. Therefore, it is necessary to apply temperature correction. In particular, at a low temperature of about 100 ° C. from room temperature, there is a fundamental problem that the amount of heat diffusion is small, temperature distribution tends to occur in the entire sensor, and temperature correction is difficult to apply.

  Furthermore, as a dielectric to be used, PLZT, PZT, etc. have hysteresis in electrostriction characteristics, and a complicated circuit for performing correction other than temperature correction is required. Furthermore, there is a problem that the electromotive force generated by the piezo element is small, the capacitance is insufficient for signal processing of the obtained electromotive force change, and the accuracy is not obtained due to some hysteresis.

  On the other hand, the strain measurement using an optical fiber as shown in Patent Document 2 has a problem that the sensitivity to a pressure of about 10 mmHg is low. This method uses a method in which the diffraction grating changes due to strain and the reflection spectrum characteristic changes. However, the pressure is not directly measured, but the pressure is indirectly evaluated from the state of expansion and contraction due to strain.

  As described above, there are various methods such as tube wall pressure detector using strain gauge, electrostrictive pressure measurement using dielectric thin film, and strain measurement using optical fiber, but temperature and hysteresis correction etc. are required. It was not possible to measure a small pressure change by a simple method.

  The present invention has been made in view of the above circumstances, and is an optical waveguide pressure sensor that has a small effect on temperature change, does not require hysteresis correction, can perform highly sensitive pressure detection, and is easy to handle. The purpose is to provide.

  1. In a pressure evaluation method using an optical waveguide, an elastic waveguide that is elastically deformed is formed on at least a part of the optical waveguide, and the elastic waveguide is brought into direct or indirect contact with the surface of a member to be inspected. A pressure evaluation method characterized by evaluating a pressure applied to the member to be inspected by detecting an optical change of transmitted light or reflected light of an optical waveguide due to elastic deformation of the optical waveguide.

  2. In a pressure evaluation method using an optical waveguide, an optically different end face that is elastically deformed is formed on at least a part of the optical waveguide, and the different end face is brought into direct or indirect contact with the surface of a member to be inspected. A pressure evaluation method for evaluating a pressure applied to a member to be inspected by detecting an optical change caused by a change in a reflection angle or an incident angle at a different phase end face due to elastic deformation of the member.

  3. By changing the volume modulus of elasticity (Pa) in the elastic waveguide formed in at least a part of the optical waveguide, the amount of elastic displacement of the elastic waveguide with respect to the pressure applied to the member to be inspected is changed. The pressure evaluation method according to claim 1, wherein the amount of change is adjusted.

  4). The pressure is determined using a correlation between at least one characteristic selected from the group consisting of the intensity of light propagating in the optical waveguide, the polarization intensity of the light, and the amount of change in the wavelength dispersion of the light, and the pressure applied to the member to be inspected. It measures, The pressure evaluation method of any one of Claims 1-3 characterized by the above-mentioned.

  5). By measuring the amount of reflected light incident on the optical waveguide on the incident side of the optical waveguide, or measuring the amount of transmitted incident light incident on the optical waveguide on the transmission side of the optical waveguide, an elastic waveguide The pressure evaluation method according to claim 1, wherein an optical change due to elastic deformation of the optical waveguide is detected.

  6). An optical waveguide type pressure sensor including an optical waveguide, comprising: a contact surface that contacts the surface of a member to be inspected; and an elastic waveguide formed on at least a part of the optical waveguide. An optical waveguide type pressure sensor that is elastically deformed by the pressure of a surface of a member to be inspected that propagates through the contact surface.

7). 7. The optical waveguide pressure sensor according to claim 6, wherein the elastic waveguide is a rubber and / or a synthetic resin having a bulk modulus of 5 × 10 ⁹ Pa or less.

  8). An optical waveguide pressure sensor including an optical waveguide, comprising: an abutting surface that abuts on a surface of a member to be inspected; and an optical different phase end surface formed on at least a part of the optical waveguide, An optical waveguide pressure sensor that is elastically deformed by the pressure of the surface of the member to be inspected that propagates through the contact surface.

  9. The optical waveguide type pressure sensor according to any one of claims 6 to 9, further comprising a detection unit that detects an optical change of light entering and exiting the optical waveguide.

  10. The optical waveguide pressure sensor according to any one of claims 6 to 9, wherein the optical waveguide is an optical fiber.

  11. A support substrate for supporting the optical waveguide provided on the side opposite to the contact surface with respect to the optical waveguide, and a pressure on the surface of the member to be inspected provided on the contact surface side to propagate to the elastic waveguide or the optical waveguide The optical waveguide pressure sensor according to claim 6, further comprising: a pressure sensitive part.

  12 Providing the optical waveguide on the opposite side of the contact surface, supporting the optical waveguide, provided between the support substrate and the optical waveguide, and propagating from the surface of the member to be inspected through the optical waveguide The optical waveguide pressure sensor according to any one of claims 6 to 11, further comprising an elastic portion that is elastically deformed by the pressure applied.

  According to the pressure evaluation method of the present invention, an elastic waveguide that is elastically deformed is formed on the surface of a member to be inspected or a support substrate, and the pressure of the member to be inspected is changed using an optical change caused by elastic deformation of the elastic waveguide. Perform pressure assessment. As this elastic waveguide, a rubber material with variously changed elastic constants, rebound elastic modulus or bulk elastic modulus is used, or a high refractive index material or a low refractive index material is added to the rubber material, and depending on pressure. The refractive index of the medium can be greatly changed by utilizing the change in the medium density. Thus, the pressure evaluation method of the present invention can provide a pressure evaluation method that is capable of highly sensitive pressure detection and is easy to handle by evaluating the intensity of propagating light and changes in the optical spectrum. .

  Further, according to the present invention, an elastic waveguide having an optically different end face (different phase interface) is formed on the surface of the member to be inspected or on the support substrate against the pressure acting on the wall surface of the member to be inspected. Then, the pressure acting on the wall surface of the member to be inspected can be detected by changing the refractive index of the medium more greatly by utilizing the change in the medium density due to the elastic deformation of the different phase interface.

  By using the optical waveguide pressure sensor of the present invention, the pressure can be evaluated by detecting the optical change, and an elastic waveguide that is elastically deformed is formed in a part of the optical waveguide, and the elastic waveguide is covered. The pressure applied to the member to be inspected in contact with the inspection member is evaluated using the optical change of the optical waveguide due to the deformation of the elastic waveguide. Thereby, compared with the past, pressure can be detected and evaluated with high sensitivity without depending on temperature. In addition, the structure is simple and easy to manufacture, and it can be handled easily, and thus has great industrial utility value.

    An embodiment of the present invention will be described below with reference to the drawings.

  According to the pressure evaluation method of the present invention, an elastic waveguide that is elastically deformed is formed in at least a part of an optical waveguide, and the pressure of the member to be inspected is measured by detecting an optical change due to the deformation of the elastic waveguide. This is a method for evaluating the pressure.

  An optical waveguide type pressure sensor according to the present invention is an optical waveguide type pressure sensor provided with an optical waveguide, wherein the contact surface is in contact with the surface of a member to be inspected, and an elastic waveguide is formed on at least a part of the optical waveguide. The elastic waveguide is configured to be elastically deformed by the pressure of the surface of the member to be inspected that propagates through the contact surface.

  The optical waveguide pressure sensor of the present invention may be provided with a detection unit that detects an optical change of light entering and exiting the optical waveguide, and the detection unit is attached to the outside of the optical waveguide pressure sensor. It may be a configuration.

  According to the present invention, an elastic waveguide that is elastically deformed is formed on the surface of a member to be inspected or a support substrate, and the pressure of the member to be inspected is detected by detecting an optical change due to elastic deformation of the elastic waveguide. It can be performed.

  Further, the pressure evaluation method of the present invention may have a configuration in which an optically different end face is formed on at least a part of the optical waveguide. The different phase end surface is configured to be elastically deformed by the pressure propagating from the surface of the member to be inspected.

  By forming the different phase end face in this manner, the pressure of the member to be inspected can be evaluated by detecting an optical change caused by a difference in reflection angle or incident angle of the different phase end face due to elastic deformation of the optical waveguide. it can.

  Specifically, for example, the different phase end face of the optical waveguide may be in a state of only a crack, that is, a state where there is air as a non-bonding interface, and other media such as a transparent rubber or plastic medium. May form a discontinuous interface. Thus, if a non-continuous interface in which the same optical waveguide material does not exist continuously is formed, the light transmittance changes at the non-continuous interface, so that when pressure is applied to the interface, The pressure acting on the surface of the member to be inspected can be estimated and evaluated from the amount of change in light.

  In any of the above methods, the formed optical waveguide does not have the same waveguide material continuous, but has a different-phase end face, that is, a discontinuous interface, or a discontinuous layer having a different elastic constant in the pressure measurement section. doing.

  The material used for the optical waveguide of the present invention or the material of the different phase end face portion is not particularly limited as long as it is a transparent material, and examples thereof include siloxane skeleton silicon rubber, polyethylene, polycarbonate, fluorine resin, and the like. It is done.

  In addition, among these materials, as other materials having relatively different refractive indexes, for example, an additive such as titanium oxide, silicon oxide, PLZT, PZT, barium titanate, etc. is added to increase the refractive index of the medium, You may use the structure which enlarges the change of the optical physical property which arises with the density change at the time of receiving a pressure. Thereby, the pressure measurement accuracy can be further improved.

  The optical waveguide of the present invention may be formed of silicon oxide or the like by a CVD or sputtering method using a crystal such as a silicon wafer as a supporting substrate, and an optical fiber is formed on an epoxy substrate of a general circuit board. It is good also as a structure to install.

As the elastic waveguide of the present invention, rubber or synthetic resin in which the elastic constant, rebound elastic modulus, or bulk elastic modulus is variously changed can be used. It is also possible to use a medium in which the refractive index of the medium is greatly changed by adding a high refractive index material or conversely a low refractive index material to the material of rubber or synthetic resin and utilizing the change in the medium density due to pressure. . For example, as the elastic waveguide, rubber or synthetic resin having a bulk modulus of 5 × 10 ⁹ Pa or less is used. The pressure evaluation method of the present invention evaluates the pressure acting on the surface of the member to be inspected by detecting the intensity of propagating light or changes in the optical spectrum using the elastic optical waveguide.

  The optical waveguide pressure sensor of the present invention is provided with a contact surface that directly or indirectly contacts the surface of the member to be inspected. Thereby, the pressure can be made uniform and propagated to the sensor side.

  The optical waveguide pressure sensor of the present invention may be provided with a support substrate that is provided on the side opposite to the contact surface and supports the optical waveguide. Further, it is preferable that a pressure-sensitive portion for propagating the pressure on the surface of the member to be inspected to the elastic waveguide is provided on the contact surface side. For example, the pressure-sensitive portion is made of the same material as the elastic waveguide, is formed integrally with the elastic waveguide, and is provided on the contact surface side with respect to the optical waveguide. Further, the pressure-sensitive portion surface may be formed as the contact surface itself. By providing the pressure sensitive part in this way, the pressure can be made uniform and propagated.

  Moreover, it is good also as a structure which provides in the opposite side to the said contact surface and provides the support substrate for supporting an optical waveguide. Moreover, it is good also as a structure which provides the elastic part elastically deformed by the pressure which propagates via the optical waveguide from the to-be-inspected member surface between a support substrate and an optical waveguide. The elastic part is formed integrally with the elastic waveguide, for example, and is fitted to the support substrate.

  The optical waveguide pressure sensor of the present invention may be provided with a hard coat film that further covers the contact surface. As the hard coat film, for example, SUS, Ni, Fe, SiO2, alumina, a glass substrate, a polyacrylic hard coat or other metal or an inorganic compound, an organic resin having a predetermined hardness, or the like is used. The contact surface itself may be formed of the hard coat film.

  In addition, the hard coat film can be formed of silicon oxide, aluminum oxide, silicon nitride, or the like by sputtering, plasma CVD, or the like to improve oxidation resistance and corrosion resistance. Thereby, depending on the state of the member to be inspected, the oxidation resistance and the corrosion resistance can be further improved in preparation for the case where the environment using the optical waveguide pressure sensor becomes an oxidizing or corrosive environment.

  Without providing the hard coat film, a contact surface is formed on the surface of the pressure-sensitive part, and the pressure of the surface of the member to be inspected is directly applied to the different phase end surface part via the pressure-sensitive part, and unevenness at the interface part It is also possible to measure the pressure distribution.

  The light propagating in the optical waveguide is not limited to light sources such as semiconductor lasers, gas lasers, light emitting diodes, and ordinary tungsten lamps, but lamps using resistance heating are appropriate when using changes in the optical spectrum. In addition, when using a change in light intensity, either LD or LED may be used.

  Hereinafter, although one Example of this invention is described according to drawing, this invention is not limited to these Examples.

  FIG. 1 is an explanatory diagram showing a schematic configuration of a pressure sensor 20 according to an embodiment of the present invention. As shown in FIG. 1, the pressure sensor 20 is installed on a 1 mm thick polycarbonate substrate 1 (support substrate), silicon rubber 2 (elastic portion) fitted on the polycarbonate substrate 1, and the silicon rubber 2. In addition, a 0.1 mmφ glass optical fiber 3 (optical waveguide) is provided.

  An elastic waveguide 6 made of silicon rubber is provided in the gap between the optical fibers 3. Silicon rubber 4 (pressure-sensitive portion) is formed on the upper surface of the optical fiber 3 so as to entirely cover the upper surface of the optical fiber 3. The silicon rubber 4, the elastic waveguide 6, and the silicon rubber 2 are integrally formed in this order. Further, an acrylic resin hard coat film 5 is formed on the silicon rubber 4 in order to equalize the pressure applied to the contact surface of the pressure sensor 20 with the member to be inspected and to improve oxidation resistance and corrosion resistance. Is formed.

  Here, the light having a GaAlAs-based LD emission wavelength of 760 nm is incident on the optical fiber 3 to one end face 6A of the optical fiber 3, and the return light is dispersed by a half mirror (not shown), and a PD (photo-detector) (detector). Measure the light intensity. Similarly, the light intensity of the transmitted light obtained from the end face 6B of the optical fiber is measured by a PD (photo-detector).

In this embodiment, silicon rubber is filled with 0.5 to 50 vol% of PZT, which is a highly refractive material, to increase the refractive index and increase the return light. By doing so, the sensitivity to the pressure acting on the discontinuous interface (the interface between the elastic waveguide 6 made of silicon rubber and the optical fiber 3) can be increased. Examples of the highly refractive material include the above-described PZT, and other examples include PLZT and barium titanate. The particle diameter was 0.5 microns, but the particle diameter is not particularly limited and may be appropriately determined as necessary.
When the ratio of the high refractive material to the silicon rubber exceeds 50 vol%, the elastic strength is lowered, which is not preferable.

  As the elastically deformable material formed on the different phase end faces, materials having different elastic deformation constants (N / m) are appropriately selected, and the amount of elastic displacement with respect to the pressure applied to the member to be inspected is changed to adjust the optical change amount. . The state at this time will be described with reference to FIG.

  As shown in FIG. 2, optical fibers 3 and 3 'divided into two parts are placed on a polycarbonate substrate 1 through silicon rubber 2, and the end faces of the two optical fibers 3 and 3' facing each other ( Fix the different phase end face) with a distance of about 1mm. At this time, a layer 12 in which air is interposed is formed between the end faces of the optical fibers 3 and 3 'facing each other. Other concave portions of the polycarbonate substrate 1 and other portions of the upper surfaces of the optical fibers 3 and 3 ′ are covered with the silicon rubber 4.

  Here, when pressure is applied to the surface of the hard coat film 5 corresponding to the upper part of the end face portion of the optical fiber 3 3 ′, each end face of the optical fibers 3 3 ′ parallel to each other, or end faces that are in a common perpendicular line are formed. Since it is inclined, the propagating light is reflected by the end face, the amount of transmitted light is reduced, and the amount of return light can be increased.

  When the optical fiber is elastically deformed with respect to the pressure on the surface of the member to be inspected, the silicon rubber supporting the optical fiber is also elastically changed. Therefore, the stress generated for a certain pressure P is equal to the stress P1 from the optical fiber and the stress P2 from the supporting silicon rubber. This is simply indicated as P = P1 + P2. Here, when the degree of crosslinking of the silicon rubber is changed to be hardened, the elastic constant K2 of the silicon rubber increases, so that the amount of strain generated by the stress P2 on the silicon rubber side decreases. If the elastic constant of the optical fiber is K1, the displacement amount X can be expressed as P = (K1 + K2) × X if the optical fiber and silicon rubber are in contact with each other and are approximated to be the same. Here, it can be seen that the displacement X decreases as the elastic constant of the silicon rubber increases.

  The fact that the amount of displacement is small means that the inclination at the end face is small, so that the amount of transmitted light is large. As a result, by changing the elastic constant of silicon rubber, the amount of change in light intensity with respect to pressure can be changed, and by changing the elastic constant of silicon rubber according to the pressure to be measured, a wide range from low pressure to high pressure can be obtained. Can be measured.

  Here, the change in the elastic constant when silicon rubber is used has been described. However, the elastic waveguide does not necessarily need to be silicon rubber, and natural rubber, synthetic rubber, etc., or a general elastomer may be used. The synthetic resin is not limited to the above. However, in the above description, air is interposed between the end faces of the optical fibers. However, when inserted between the end faces for strength stability, it is preferable to be as transparent as possible because the transmitted light intensity can be obtained.

  The configuration using an optical fiber as the optical waveguide has been described above. Next, a case where an optical waveguide not using an optical fiber is formed on a silicon substrate will be described with reference to FIG.

  After forming silicon oxide having a width of 100 microns and a thickness of 200 microns on the crystalline silicon substrate 13 by CVD, a silicon oxide optical waveguide 10 having a cross section as shown in FIG. 3 is formed by lithography. . At this time, a gap of 3 mm is formed between the silicon oxide optical waveguide 10 and the crystalline silicon substrate 13. In this figure, an elastic waveguide 9 using a silicon-based gel medium in which 0.3 micron silicon oxide powder is dispersed is formed in the middle portion of the silicon oxide optical waveguide 10. These upper surfaces are covered with a PET film 11 having a thickness of about 10 microns.

In the optical waveguide having the different phase end face in FIG. 1 above, when the pressure is changed from 10 mmHg to 300 mmHg using a 10 mW GaAlAs laser, the reflection intensity and the transmitted light intensity change as shown in FIG. The correlation was confirmed.
The relative value on the vertical axis in Fig. 4 is defined as the amount of change in reflection divided by the amount of change at 300 mmHg in the case of reflection, and the amount of change in transmitted light at 300 mmHg in the case of transmitted light Defined as divided by quantity and expressed as a percentage. Similarly, the same tendency was obtained with the optical waveguide pressure sensor having the structure of FIG.

FIG. 5 shows the result of changing the reflected light at a constant pressure of 300 mmHg when the elastic modulus is changed by changing the degree of crosslinking of the silicon rubber in the elastic waveguide 6 in FIG. The abscissa indicates the volume modulus (10 ⁹ Pa), and the ordinate indicates the relative value (%) normalized by the maximum value of the change in light reflection. From this result, it was found that the change of reflected light can be changed by changing the bulk modulus.

  In addition, this invention is not limited only to the said Example, In addition to being applicable also with respect to a gas pressure, a water pressure, etc., it can be applied and developed with the same structure also about a low pressure.

    The pressure evaluation method of the present invention and the use of a pressure sensor using an optical waveguide include, for example, fluid transport pipes and pressure vessels used in chemical plants, pharmaceutical plants, and pipes such as daily gas and water pipes. Applications include a wall pressure detector and a pressure sensor for measuring water pressure and gas pressure.

It is explanatory drawing which shows schematic structure of the optical waveguide type pressure sensor which concerns on one embodiment of this invention. It is explanatory drawing which shows schematic structure of the optical waveguide type pressure sensor which concerns on other embodiment of this invention. It is explanatory drawing which shows schematic structure of the optical waveguide type pressure sensor using the silicon oxide formed on the crystalline silicon substrate as an optical waveguide. It is a graph which shows the relationship between a pressure, reflection intensity, and transmitted light intensity. It is a graph which shows the relationship between a volume elastic modulus and reflected light.

Explanation of symbols

1 Polycarbonate substrate (support substrate)
2 Silicone rubber (elastic part)
3 Optical fiber (optical waveguide)
4 Silicone rubber (pressure sensitive part, contact surface)
5 Hard coat film (contact surface)
6 Elastic waveguide 10 Silicon oxide optical waveguide 11 PET film (contact surface)
12 Layer with air 13 Crystalline silicon substrate (support substrate)

Claims (12)

In a pressure evaluation method using an optical waveguide, an elastic waveguide that is elastically deformed is formed on at least a part of the optical waveguide, and the elastic waveguide is brought into direct or indirect contact with the surface of a member to be inspected. A pressure evaluation method characterized by evaluating a pressure applied to the member to be inspected by detecting an optical change of transmitted light or reflected light of an optical waveguide due to elastic deformation of the optical waveguide. In a pressure evaluation method using an optical waveguide, an optically different end face that is elastically deformed is formed on at least a part of the optical waveguide, and the different end face is brought into direct or indirect contact with the surface of a member to be inspected. A pressure evaluation method for evaluating a pressure applied to a member to be inspected by detecting an optical change caused by a change in a reflection angle or an incident angle at a different phase end face due to elastic deformation of the member. By changing the volume modulus of elasticity (Pa) in the elastic waveguide formed in at least a part of the optical waveguide, the amount of elastic displacement of the elastic waveguide with respect to the pressure applied to the member to be inspected is changed. The pressure evaluation method according to claim 1, wherein the amount of change is adjusted. The pressure is determined using a correlation between at least one characteristic selected from the group consisting of the intensity of light propagating in the optical waveguide, the polarization intensity of the light, and the amount of change in the wavelength dispersion of the light, and the pressure applied to the member to be inspected. It measures, The pressure evaluation method of any one of Claims 1-3 characterized by the above-mentioned. By measuring the amount of reflected light incident on the optical waveguide on the incident side of the optical waveguide, or measuring the amount of transmitted incident light incident on the optical waveguide on the transmission side of the optical waveguide, an elastic waveguide The pressure evaluation method according to claim 1, wherein an optical change due to elastic deformation of the optical waveguide is detected. An optical waveguide type pressure sensor including an optical waveguide, comprising: a contact surface that contacts the surface of a member to be inspected; and an elastic waveguide formed on at least a part of the optical waveguide. An optical waveguide type pressure sensor that is elastically deformed by the pressure of a surface of a member to be inspected that propagates through the contact surface. 7. The optical waveguide pressure sensor according to claim 6, wherein the elastic waveguide is a rubber and / or a synthetic resin having a bulk modulus of 5 × 10 ⁹ Pa or less. An optical waveguide pressure sensor including an optical waveguide, comprising: an abutting surface that abuts on a surface of a member to be inspected; and an optical different phase end surface formed on at least a part of the optical waveguide, An optical waveguide pressure sensor that is elastically deformed by the pressure of the surface of the member to be inspected that propagates through the contact surface. 9. The optical waveguide type pressure sensor according to claim 6, further comprising a detection unit that detects an optical change of light entering and exiting the optical waveguide. The optical waveguide pressure sensor according to any one of claims 6 to 9, wherein the optical waveguide is an optical fiber. A support substrate for supporting the optical waveguide provided on the side opposite to the contact surface with respect to the optical waveguide, and a pressure on the surface of the member to be inspected provided on the contact surface side to propagate to the elastic waveguide or the optical waveguide The optical waveguide pressure sensor according to claim 6, further comprising: a pressure sensitive part. Providing the optical waveguide on the opposite side of the contact surface, supporting the optical waveguide, provided between the support substrate and the optical waveguide, and propagating from the surface of the member to be inspected through the optical waveguide The optical waveguide pressure sensor according to any one of claims 6 to 11, further comprising an elastic portion that is elastically deformed by the pressure applied.

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