CN113916837B - Optical fiber V-groove type cladding SPR curvature sensor capable of identifying direction and manufacturing method thereof - Google Patents
Optical fiber V-groove type cladding SPR curvature sensor capable of identifying direction and manufacturing method thereof Download PDFInfo
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
- G01N21/17—Systems in which incident light is modified in accordance with the properties of the material investigated
- G01N21/55—Specular reflectivity
- G01N21/552—Attenuated total reflection
- G01N21/553—Attenuated total reflection and using surface plasmons
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N2201/00—Features of devices classified in G01N21/00
- G01N2201/08—Optical fibres; light guides
- G01N2201/088—Using a sensor fibre
Abstract
The invention belongs to the field of optical fiber sensing, and mainly relates to an optical fiber V-groove cladding SPR curvature sensor capable of identifying directions; the device comprises a sensing optical fiber and a light receiving step multimode optical fiber which are connected in sequence; the sensing optical fiber is carved with a V-groove structure, the sensing optical fiber receives and transmits a light beam emitted by a light source, the light in the fiber core is coupled into the cladding when passing through the V-groove structure, an SPR effect is generated between the light and a metal film covered on the surface of the cladding, and finally, the light receiving step multimode optical fiber receives light and transmits a light signal to the spectrometer for signal acquisition and demodulation; according to the invention, the V-shaped groove is engraved on the sensing optical fiber, so that light in the fiber core is effectively coupled into the cladding, the difficult problem that an evanescent field of the cladding type optical fiber SPR sensor is difficult to obtain is solved, the shape of the V-shaped groove is changed by changing the bending degree of the optical fiber, the SPR incidence angle is changed, SPR resonance Gu Pianyi is realized, and the high-sensitivity bending measurement and the direction recognition capability are realized.
Description
Technical Field
The invention belongs to the field of optical fiber sensors, and particularly relates to an optical fiber V-groove type cladding SPR curvature sensor capable of identifying directions and a manufacturing method thereof.
Background
The Surface Plasmon Resonance (SPR) technology becomes a research hot spot because of the advantages of high sensitivity, electromagnetic interference resistance, no need of marking, long-distance measurement and the like. The SPR sensing principle is as follows: when light waves are emitted from an optically dense medium to an optically sparse medium, reflection and refraction occur at the interface of the two mediums, if the incident angle is larger than a critical angle, refraction does not occur, the reflected light waves and the incident light wave energy are equal, the phenomenon is called total reflection, when total reflection occurs, after the incident light irradiates the interface of the two mediums, the light wave energy is totally reflected back to the optically dense medium, but is not reflected back at the interface, but penetrates a very thin layer in the optically sparse medium, the thickness is in the order of the wavelength of the light wave, the partially penetrated electromagnetic wave is called evanescent wave, the evanescent wave excites surface plasmas on the metal surface, resonance occurs between the evanescent wave and the metal surface plasmas under certain conditions, at this time, the energy of the reflected light is reduced due to partial absorption of the incident light energy, resonance peaks are formed, and when the refractive indexes of the optical medium are different, the resonance peaks are deviated, and the principle of detecting refractive index parameters of the medium to be detected by the optical fiber SPR sensor is the principle of detecting the refractive index parameter of the medium to be detected.
In practical applications, many building structures bend due to load, and in such buildings, the need for bending measurement increases, and the judgment of the bending direction is also important for the detection of the building structure. Accordingly, based on the MZI, FBG, LPFG type of optical fiber bending sensor, several types of optical fiber sensors are proposed for bending sensing and direction recognition by having an asymmetric structure or using asymmetric special optical fibers, which exhibit advantages of high sensitivity to bending and direction recognition, but most of the sensors use special optical fibers, which are costly, complicated in operation process, and expensive in signal demodulation equipment.
However, there are few studies to combine the SPR technique with bending sensing, and the relation between the SPR technique and the bending sensing is to be established, firstly, ensuring that the SPR effect occurs and secondly, the relation between the bending and the SPR resonance wavelength is to be established.
For SPR effect occurrence conditions, the structural conditions of SPR occurrence are as follows: the evanescent wave needs to enter the metal film, namely, the evanescent wave contacts the metal film when the total reflection of transmitted light is required. In the case of an optical fiber waveguide, the transmission light is totally reflected at the interface between the fiber core and the cladding, so that the transmission light is transmitted in the fiber core, and the transmission light is not transmitted in the cladding, and when the structure of the optical fiber SPR sensor is constructed, the problem to be solved is how to make the transmission light contact with the gold film when totally reflected. There are two approaches to solving this problem: namely core-type SPR sensors and cladding-type SPR sensors. The fiber core type optical fiber SPR sensor needs to remove the optical fiber cladding so that an evanescent field contacts with a metal film to generate an SPR effect, and the currently used methods are corrosion, polishing and grinding of the side surface of the optical fiber or grinding of the optical fiber, but the processing methods have the problems of difficult processing, reduced mechanical strength, poor repeatability and the like of the optical fiber, and the usability is not high. The cladding type optical fiber SPR sensor needs to couple transmission light leakage in an optical fiber core into an optical fiber cladding so that an evanescent field contacts a metal film to generate an SPR effect, and the existing method comprises a tapering structure, a heterogeneous core structure and a U-shaped structure, but the optical fiber SPR sensor with the tapering structure is easy to break and has poor recycling property; the heterogeneous core structure is usually a multimode-single mode-multimode optical fiber structure, and SPR sensing on the multimode optical fiber cladding cannot be realized by the method; the U-shaped structure is difficult to repeatedly manufacture and generates bending loss.
For SPR bending sensing: the optical fiber is bent, light in the fiber core of the optical fiber gradually leaks into the cladding and the air, and the bending degrees are different, so that the total reflection angles of the light in the optical fiber are different, namely, the SPR incidence angles are different, the SPR incidence angles influence the wavelength range of the SPR resonance valley, and therefore, the problem to be solved at present is how to establish the relation between the bending and the SPR incidence angles in order to realize SPR bending sensing.
The current solutions are: takagi et al have studied the enhancement of sensitivity of optical fiber SPR sensors by doubling the SPR formant loss through bending using heterogeneous core structure optical fiber sensors, but only theorized direct relationship of fiber bending curvature to SPR spectral lines. Su Yudong et al reported in 2018 a temperature compensation based optical fiber SPR curvature sensor. The Shen et al used ring core fiber to realize distributed curvature sensing, but mechanical bending was directional, but none of these studies realized direction recognition, and an optical fiber semi-film SPR curvature sensor proposed in 2020 realized bending direction recognition, but was less sensitive.
Based on this, the problem to be solved by the present invention is to provide a simple optical fiber cladding type SPR sensor and a method for measuring curvature with high accuracy based on the same.
Disclosure of Invention
In view of the above, an object of the present invention is to provide an optical fiber V-groove cladding SPR curvature sensor capable of direction recognition, and a method for measuring curvature based on the sensor.
In order to achieve the above purpose, the present invention provides the following technical solutions:
the optical fiber V-groove type cladding SPR curvature sensor capable of identifying the direction comprises sensing optical fibers and light receiving step multimode optical fibers which are connected in sequence; the right end of the sensing optical fiber is directly welded with the left end of the light receiving step multimode optical fiber, the sensing optical fiber is fixed on an object to be tested and bent (for convenience of test and verification, the bending test device can be fixed on a bending test device by using a clamp), the left end of the sensing optical fiber is connected with a wide-spectrum light source to transmit light beams, the sensing optical fiber is provided with a V-groove structure, when the light beams reach the V-groove structure, light in a fiber core is coupled into a cladding, after the light beams generate a Surface Plasmon Resonance (SPR) effect with a metal film covered on the surface of the cladding, reflected light enters the left end of the light receiving step multimode optical fiber, the right end of the light receiving step multimode optical fiber is connected with a spectrometer, and the spectrometer collects and demodulates signals; by CO 2 The laser is used for carving a V-shaped groove on the sensing optical fiber, so that light in the fiber core is effectively coupled into the cladding, and the problem that an evanescent field of the cladding type optical fiber SPR sensor is difficult to obtain is solved; the shape of the V-shaped groove is changed by changing the bending degree of the optical fiber, when the V-shaped groove is concavely bent inwards, the extrusion angle of the V-shaped groove is reduced, the SPR incidence angle is correspondingly increased, and the SPR resonance valley is blue-shifted; when the V groove is outwards convexly bent, the angle of the V groove is enlarged by expanding, the SPR incidence angle is correspondingly reduced, SPR resonance Gu Gongyi is realized, and the high-sensitivity bending measurement and the direction recognition capability are realized.
The bending test device comprises a micro-manipulator, a motor, a three-dimensional micro-stage, a jack post and a rotator. The micro-manipulator is connected with the motor through a cable, the three-dimensional micro-motion stage is positioned above the motor, and the three-dimensional micro-motion stage can be controlled to move in the three-dimensional direction through the motor. The jack post is installed on the rotator, and the bending of optical fiber can be realized through the jack post, makes the jack post direction take place 180 changes in order to realize different bending direction through rotatory rotator.
As a preferable scheme, the sensing optical fiber has a V-groove structure, can effectively couple light in a fiber core into a cladding, and is a step multimode optical fiber, wherein the fiber core diameter is 40 mu m, the cladding diameter is 125 mu m, and the numerical aperture is 0.22; the manufacturing method of the V-shaped groove comprises the following steps: placing bare fiber with stripped coating layer in CO 2 On a three-dimensional micro-motion stage below a laser, one end of a bare fiber is fixed by an optical fiber clamp, and a light weight is hung at the other end of the optical fiber to ensure that the optical fiber keeps constant axial stress in the heating process and is always in a horizontal straight line state, and a computer is used for designing CO (carbon monoxide) 2 The number and period of the V-shaped grooves processed by the laser can be changed by changing the processing times.
Preferably, the fiber core diameter of the light-receiving step multimode fiber is 105 μm, the cladding diameter is 125 μm, and the numerical aperture is 0.22.
As a preferable scheme, the manufacturing method comprises the following steps:
s1, taking a section of enough-length step multimode fiber, wherein the diameter of a fiber core is 40 mu m, the diameter of a cladding is 125 mu m, stripping a coating layer of 10cm from one end of the step multimode fiber by using a Muller clamp, dipping alcohol into non-woven fabrics, wiping the non-woven fabrics, and placing the bare fiber stripped with the coating layer in CO 2 On a three-dimensional micro-motion stage below the laser, one end of the bare fiber is fixed by an optical fiber clamp, and the other end of the optical fiber is suspended with a light weight to keep constant axial stress of the optical fiber in the heating process and always in a horizontal straight line state, and the optical fiber is in a CO (carbon monoxide) state 2 The laser processing parameters are set to 800 mm/s processing speed, 50% power and 5KHz frequency, the number and period of V-grooves are designed by a computer, and the depth of the V-grooves can be changed by changing the processing times. Taking out the optical fiber after the V-groove carving, cutting the optical fiber with a length of 2cm after the V-groove is cut by a fixed-length cutting device to be used as a sensing area, and wiping the other end of the optical fiber with alcohol for clean placement for later use after the other end of the optical fiber is subjected to cutting and leveling treatment;
s2, taking a section of large-core-diameter step multimode optical fiber (the diameter of a fiber core is 105 mu m, the diameter of a cladding is 125 mu m) with the length of 50cm, cutting the two ends, wiping the two ends with alcohol, and placing the two ends aside for later use;
s3, directly welding one end of a prepared V-groove structure step multimode optical fiber sensing area and one end of a large-core step multimode optical fiber by utilizing an automatic welding mode of an optical fiber welding machine, wiping cleanly with alcohol after the welding is finished, placing the sensing area on a glass slide, fixing the two ends with traceless glue, placing the sensing area in a small plasma sputtering instrument (ETD-2000, externally connected with a film thickness monitor), covering the V-groove area by using the glass slide to avoid plating a gold film, circularly plating a 50nm gold film on the sensing area after the V-groove, and finishing manufacturing the step multimode optical fiber V-groove cladding SPR sensor;
s4, placing the cladding region plated with the gold film into an optical fiber coater to coat the polymer, wherein the coating is ultraviolet curing glue with the refractive index of 1.375, providing a refractive index environment capable of generating SPR for a sensing probe and playing a role in protecting the gold film and the optical fiber, and the outer diameter of the coating is 250 mu m and the length of the coating is 2cm. After the sensing probe is mechanically bent, the evanescent field changes in the bent portion, and thus the SPR resonance wavelength changes accordingly.
S5, connecting a step multimode optical fiber at the left end of a probe with a light source, placing a step multimode optical fiber sensing area right below a jack post, controlling the jack post to contact a sensing probe through a micro-manipulator to bend the optical fiber, exciting a cladding mode when light emitted by the light source passes through a V-shaped groove structure, enabling transmission light to generate total reflection and surface plasma resonance at an interface between the cladding and a metal film, enabling reflected optical signals to enter a spectrometer through a step-index multimode receiving optical fiber with a core diameter of 105 mu m, collecting and demodulating the transmitted reflection spectrum by the spectrometer, storing reflection spectrum data, and processing the data by MATLAB simulation software to obtain reflection spectrum curves under different bending degrees; when one side of the V groove is concave inwards (0-degree bending direction), the extrusion angle of the V groove is reduced, so that the SPR incidence angle is increased, and the resonance valley is blue shifted; when one side of the V groove protrudes outwards (180 DEG bending direction), the V groove expands to enlarge the angle, so that the SPR incidence angle is reduced, the resonance valley is red shifted, and the direction identification can be realized.
The invention has the beneficial effects that:
by CO 2 The laser processes the V-groove on the sensing optical fiber, and effectively couples the light in the fiber core into the cladding. When the V-groove optical fiber is bent, the V-groove structure is deformed, and the SPR incidence angle is changed, so that the relation between the bending and the SPR incidence angle is established, and further, the high-sensitivity bending measurement can be realized through the offset of the SPR resonance valley. When the V groove is concave inwards, the extrusion angle of the V groove is reduced, so that the SPR incidence angle is increased, and the resonance valley is blue shifted; when the V groove protrudes outwards, the V groove expands to enlarge the angle, so that the SPR incidence angle is reduced, the resonance valley is red shifted, and direction identification is realized.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and other advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out in the specification.
Drawings
In order to make the objects, technical solutions and advantageous effects of the present invention more clear, the present invention provides the following drawings for description:
FIG. 1 is a schematic diagram of the overall composition of the present invention;
FIG. 2 is a schematic diagram of a fiber V-groove cladding SPR curvature sensor probe with direction identification;
FIG. 3 is a cross-sectional view corresponding to the AA ', BB ', CC ', DD ' plane of FIG. 2, wherein FIG. (a) is a step multimode fiber cross-sectional view corresponding to the AA ' plane; FIG. b is a cross-sectional view of a V-groove structure of a step multimode fiber corresponding to the BB' plane; FIG. (c) is a cross-sectional view of the cladding coating after the V-groove of the step multimode fiber corresponding to the CC' plane; FIG. (d) shows a cross-sectional view of a light-receiving step multimode optical fiber corresponding to the DD' plane;
FIG. 4 is a schematic view of the V-groove shape when the V-groove is concavely curved inwards (0 deg. direction) and when the V-groove is convexly curved outwards (180 deg. direction);
fig. 5 is a structural view of the bending test device.
Detailed Description
Other advantages and effects of the present invention will become apparent to those skilled in the art from the following disclosure, which describes the embodiments of the present invention with reference to specific examples. The invention may be practiced or carried out in other embodiments that depart from the specific details, and the details of the present description may be modified or varied from the spirit and scope of the present invention. It should be noted that the illustrations provided in the following embodiments merely illustrate the basic idea of the present invention by way of illustration, and the following embodiments and features in the embodiments may be combined with each other without conflict.
Wherein the drawings are for illustrative purposes only and are shown in schematic, non-physical, and not intended to limit the invention; for the purpose of better illustrating embodiments of the invention, certain elements of the drawings may be omitted, enlarged or reduced and do not represent the size of the actual product; it will be appreciated by those skilled in the art that certain well-known structures in the drawings and descriptions thereof may be omitted.
The same or similar reference numbers in the drawings of embodiments of the invention correspond to the same or similar components; in the description of the present invention, it should be understood that, if there are terms such as "upper", "lower", "left", "right", "front", "rear", etc., that indicate an azimuth or a positional relationship based on the azimuth or the positional relationship shown in the drawings, it is only for convenience of describing the present invention and simplifying the description, but not for indicating or suggesting that the referred device or element must have a specific azimuth, be constructed and operated in a specific azimuth, so that the terms describing the positional relationship in the drawings are merely for exemplary illustration and should not be construed as limiting the present invention, and that the specific meaning of the above terms may be understood by those of ordinary skill in the art according to the specific circumstances.
Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings.
Referring to fig. 1, reference numerals in the drawings indicate: a broad spectrum light source 1, a sensing optical fiber 2, a light receiving step multimode optical fiber 3, a bending test device 4 and a spectrometer 5.
The invention relates to an optical fiber V-groove type cladding SPR curvature sensor capable of identifying directions, wherein a sensing optical fiber 2 has a V-groove structure, can effectively couple light in a fiber core into a cladding, and the sensing optical fiber 2 is a step multimode optical fiber, the fiber core diameter is 40 mu m, the cladding diameter is 125 mu m, and the numerical aperture is 0.22; the manufacturing method of the V-shaped groove comprises the following steps: placing bare fiber with stripped coating layer in CO 2 On a three-dimensional micro-motion stage below a laser, one end of a bare fiber is fixed by an optical fiber clamp, and a light weight is hung at the other end of the optical fiber to ensure that the optical fiber keeps constant axial stress in the heating process and is always in a horizontal straight line state, and a computer is used for designing CO (carbon monoxide) 2 The number and period of the V-shaped grooves processed by the laser can be changed by changing the processing times. The core diameter of the optical step multimode fiber 3 is 105 μm, the cladding diameter is 125 μm, and the numerical aperture is 0.22. The bending test device 4 comprises a left motor 4-1, a right motor 4-2, a left three-dimensional micro-motion stage 4-3, a right three-dimensional micro-motion stage 4-4, a micro-manipulator 4-5, a jack post 4-6 and a rotator 4-7, wherein the left three-dimensional micro-motion stage 4-3 is arranged on the left motor 4-1, the right three-dimensional micro-motion stage 4-4 is arranged on the right motor 4-2, the left three-dimensional micro-motion stage 4-3 and the right three-dimensional micro-motion stage 4-4 are provided with optical fiber clamps for clamping and fixing optical fibers, and the micro-manipulator 4-5 is connected with the left motor 4-1 and the right motor 4-2 through cables so as to control the movement of the left motor and the right motor in the three-dimensional direction; the jacking column 4-6 is connected with the rotator 4-7, the jacking column 4-6 gives a certain pressure to the optical fiber to bend the optical fiber, and the jacking column 4-6 can be driven to face different directions by rotating the rotator 4-7, so that the optical fiber can be bent in different directions.
The concrete connection mode is as follows: the right end of the sensing optical fiber 2 is just welded with the left end of the light receiving step multimode optical fiber 3, the sensor is fixed on the bending test device 4 by a clamp, the left end of the sensing optical fiber 2 is connected with the broad spectrum light source 1 to transmit light beams, the sensing optical fiber 2 is provided with a V-groove structure, when the light beams reach the V-groove structure, the light coupling in the fiber core enters the cladding, after the Surface Plasmon Resonance (SPR) effect occurs with a metal film covered on the surface of the cladding, the reflected light enters the left end of the light receiving step multimode optical fiber 3, the right end of the light receiving step multimode optical fiber 3 is connected with the spectrometer 5, and the spectrometer 5 collects and demodulates signals.
The specific manufacturing method comprises the following steps: the method comprises the following steps:
s1, taking a section of enough-length step multimode fiber, wherein the diameter of a fiber core is 40 mu m, the diameter of a cladding is 125 mu m, stripping a coating layer of 10cm from one end of the step multimode fiber by using a Muller clamp, dipping alcohol into non-woven fabrics, wiping the non-woven fabrics, and placing the bare fiber stripped with the coating layer in CO 2 On a three-dimensional micro-motion stage below the laser, one end of the bare fiber is fixed by an optical fiber clamp, and the other end of the optical fiber is suspended with a light weight to keep constant axial stress of the optical fiber in the heating process and always in a horizontal straight line state, and the optical fiber is in a CO (carbon monoxide) state 2 The laser processing parameters are set to 800 mm/s processing speed, 50% power and 5KHz frequency, the number and period of V-grooves are designed by a computer, and the depth of the V-grooves can be changed by changing the processing times. Taking out the optical fiber after V groove carving (V groove parameters are that the V groove period is 571 mu m, the V groove depth is 67 mu m, the number of V grooves is 30), cutting the optical fiber into a sensing area with a fixed-length cutting device after V grooves by 2cm, and wiping the other end of the optical fiber with alcohol for later use after the other end of the optical fiber is flattened;
s2, taking a section of large-core-diameter step multimode optical fiber (the diameter of a fiber core is 105 mu m, the diameter of a cladding is 125 mu m) with the length of 50cm, cutting the two ends, wiping the two ends with alcohol, and placing the two ends aside for later use;
s3, directly welding one end of a prepared V-groove structure step multimode optical fiber sensing area and one end of a large-core step multimode optical fiber by utilizing an automatic welding mode of an optical fiber welding machine, wiping cleanly with alcohol after the welding is finished, placing the sensing area on a glass slide, fixing the two ends with traceless glue, placing the sensing area in a small plasma sputtering instrument (ETD-2000, externally connected with a film thickness monitor), covering the V-groove area by using the glass slide to avoid plating a gold film, circularly plating a 50nm gold film on the sensing area after the V-groove, and finishing manufacturing the step multimode optical fiber V-groove cladding SPR sensor;
s4, placing the cladding region plated with the gold film into an optical fiber coater to coat the polymer, wherein the coating is ultraviolet curing glue with the refractive index of 1.375, providing a refractive index environment capable of generating SPR for a sensing probe and playing a role in protecting the gold film and the optical fiber, and the outer diameter of the coating is 250 mu m and the length of the coating is 2cm. After the sensing probe is mechanically bent, the evanescent field changes in the bent portion, and thus the SPR resonance wavelength changes accordingly.
The bending test device comprises a micro-manipulator, a motor, a three-dimensional micro-stage, a jack post and a rotator. The micro-manipulator is connected with the motor through a cable, the three-dimensional micro-motion stage is positioned above the motor, and the three-dimensional micro-motion stage can be controlled to move in the three-dimensional direction through the motor. The jack post is installed on the rotator, and the bending of optical fiber can be realized through the jack post, makes the jack post direction take place 180 changes in order to realize different bending direction through rotatory rotator.
S5, connecting the left-end step multimode optical fiber of the probe with a light source 1 according to the experimental device of FIG. 1, arranging a step multimode optical fiber sensing area right below a jack post, controlling the jack post to contact with a sensing probe by a micro-operator to bend the optical fiber, exciting a cladding mode when light emitted by the light source 1 passes through a V-groove structure, enabling transmission light to generate total reflection and surface plasma resonance at an interface of the cladding and a metal film, enabling reflected optical signals to enter a spectrometer 4 through a step-index multimode receiving optical fiber 3 with a core diameter of 105 mu m, collecting and demodulating the transmitted reflection spectrum by the spectrometer 5, storing reflection spectrum data, and processing the data by MATLAB simulation software to obtain reflection spectrum curves under different bending degrees. As shown in fig. 4, when one side of the V groove is concave inwards (0 ° bending direction), the extrusion angle of the V groove is reduced, so that the SPR incidence angle is increased, and the resonance valley is blue shifted; when one side of the V groove protrudes outwards (180 DEG bending direction), the V groove expands to enlarge the angle, so that the SPR incidence angle is reduced, the resonance valley is red shifted, and the direction identification can be realized.
Finally, it is noted that the above-mentioned preferred embodiments are only intended to illustrate rather than limit the invention, and that, although the invention has been described in detail by means of the above-mentioned preferred embodiments, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the scope of the invention as defined by the appended claims.
Claims (4)
1. The optical fiber V-groove type cladding SPR curvature sensor capable of identifying the direction comprises sensing optical fibers and light receiving step multimode optical fibers which are connected in sequence; the right end of the sensing optical fiber is welded with the left end of the light receiving step multimode optical fiber, and the left end of the sensing optical fiber is connected with the wide-spectrum light source to transmit light beams, and the light beam detection device is characterized in that: the sensing optical fiber is fixed on a curved object to be measured, a V-groove structure is arranged on the sensing optical fiber, light in a fiber core enters a cladding when a light beam reaches the V-groove structure, after a surface plasma resonance effect occurs between the light beam and a metal film covered on the surface of the cladding, reflected light enters the left end of the light receiving step multimode optical fiber, the right end of the light receiving step multimode optical fiber is connected with a spectrometer, and the spectrometer collects and demodulates signals.
2. The direction-identifiable optical fiber V-groove cladding SPR curvature sensor of claim 1, wherein: the sensing optical fiber is a step multimode optical fiber, the fiber core diameter is 40 mu m, the cladding diameter is 125 mu m, and the numerical aperture is 0.22.
3. The direction-identifiable optical fiber V-groove cladding SPR curvature sensor of claim 1, wherein: the fiber core diameter of the light receiving step multimode fiber is 105 mu m, the cladding diameter is 125 mu m, and the numerical aperture is 0.22.
4. The direction-identifiable optical fiber V-groove cladding SPR curvature sensor of claim 1, wherein: the specific manufacturing method comprises the following steps:
s1, taking a section of step multimode fiber, wherein the diameter of the fiber core is 40 mu m, the diameter of the cladding is 125 mu m, stripping the coating layer and using CO 2 Laser device etches V-groove structure on it, CO 2 The processing parameters of the laser are set to be 50% of power and 5KHz of frequency, and the optical fiber after V-groove carving is intercepted to be used as a sensing area;
s2, taking a section of large-core-diameter step multimode optical fiber, wherein the diameter of the fiber core is 105 mu m, the diameter of the cladding is 125 mu m, and cutting and flattening the two ends for later use;
s3, directly welding one end of the prepared V-groove structure step multimode fiber sensing area with one end of the large-core step multimode fiber, and circularly plating a 50nm gold film on the sensing area behind the V groove by a plasma sputtering instrument after the welding is finished, thereby completing the manufacturing of the step multimode fiber V-groove cladding SPR sensor;
s4, coating a polymer on the cladding region plated with the gold film, wherein the coating is ultraviolet curing glue with the refractive index of 1.375, provides a refractive index environment capable of generating SPR for a sensing probe, plays a role in protecting the gold film and the optical fiber, and finally obtains the V-groove cladding SPR curvature sensor;
s5, connecting the step multimode optical fiber at the left end of the probe with a light source, bending the step multimode optical fiber sensing area, exciting a cladding mode when light emitted by the light source passes through a V-groove structure, generating total reflection and surface plasmon resonance on an interface between the cladding and a metal film by transmission light, enabling reflected light signals to enter a spectrometer through the step-index multimode light receiving optical fiber with the core diameter of 105 mu m, collecting and demodulating the transmitted reflection spectrum by the spectrometer, storing reflection spectrum data, and drawing reflection spectrum curves under different bending degrees, thereby obtaining the corresponding relation between an SPR incidence angle and the bending degree.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5327225A (en) * | 1993-01-28 | 1994-07-05 | The Center For Innovative Technology | Surface plasmon resonance sensor |
| CN1712928A (en) * | 2005-07-01 | 2005-12-28 | 重庆工学院 | MZ interference SPR chemical and biological sensor and system with fibre-optical microstructure |
| CN110208220A (en) * | 2019-06-03 | 2019-09-06 | 天津大学 | A kind of multicore less fundamental mode optical fibre local surface plasma resonance sensor |
| CN111457861A (en) * | 2020-05-25 | 2020-07-28 | 重庆三峡学院 | Sensing optical fiber capable of identifying curvature by temperature and direction and manufacturing and using method |
| CN111457862A (en) * | 2020-05-25 | 2020-07-28 | 重庆三峡学院 | Optical fiber SPR curvature sensor with direction recognition function and using and manufacturing method thereof |
| CN112432929A (en) * | 2020-12-08 | 2021-03-02 | 桂林电子科技大学 | V-groove structure plastic optical fiber SPR sensor and preparation method thereof |
| CN113310507A (en) * | 2021-05-27 | 2021-08-27 | 重庆三峡学院 | Optical fiber SPR sensor for measuring displacement and angle, calibration device and method |
Family Cites Families (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005121461A (en) * | 2003-10-16 | 2005-05-12 | Tama Tlo Kk | Optical fiber sensor and measuring device using sensor |
| US8649014B2 (en) * | 2009-10-02 | 2014-02-11 | Lehigh University | Vertical plasmonic Mach-Zehnder interferometer |
-
2021
- 2021-11-17 CN CN202111361049.6A patent/CN113916837B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5327225A (en) * | 1993-01-28 | 1994-07-05 | The Center For Innovative Technology | Surface plasmon resonance sensor |
| CN1712928A (en) * | 2005-07-01 | 2005-12-28 | 重庆工学院 | MZ interference SPR chemical and biological sensor and system with fibre-optical microstructure |
| CN110208220A (en) * | 2019-06-03 | 2019-09-06 | 天津大学 | A kind of multicore less fundamental mode optical fibre local surface plasma resonance sensor |
| CN111457861A (en) * | 2020-05-25 | 2020-07-28 | 重庆三峡学院 | Sensing optical fiber capable of identifying curvature by temperature and direction and manufacturing and using method |
| CN111457862A (en) * | 2020-05-25 | 2020-07-28 | 重庆三峡学院 | Optical fiber SPR curvature sensor with direction recognition function and using and manufacturing method thereof |
| CN112432929A (en) * | 2020-12-08 | 2021-03-02 | 桂林电子科技大学 | V-groove structure plastic optical fiber SPR sensor and preparation method thereof |
| CN113310507A (en) * | 2021-05-27 | 2021-08-27 | 重庆三峡学院 | Optical fiber SPR sensor for measuring displacement and angle, calibration device and method |
Non-Patent Citations (4)
| Title |
|---|
| Integrated architecture for the electrical detection of plasmonic resonances based on high electron mobility photo-transistors;Sammito, Davide;《NANOSCALE》;第1390-1397页 * |
| Surface plasmon resonances of a curved hetero-core optical fiber sensor;Takagi, Keiju;《SENSORS AND ACTUATORS A-PHYSICAL》;第1-5页 * |
| 新型结构的光纤表面等离子体共振传感器及其生化应用研究;陈郁芝;《中国优秀博士学位论文全文数据库》;全文 * |
| 阶跃折射率多模光纤包层等离子体共振传感器;魏勇;《光学精密工程》;第2525-2533页 * |
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