JP2006170709A - Sensor head connection method for optical fiber sensor system and its device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make only a sensor head disposable, thereby reducing the operation cost of a sensor system in its entirety. <P>SOLUTION: In this sensor head connection device 1 or 2 for an optical fiber sensor system, empty ferrules 15, 15a and 15b are mounted on connectors 11, 11a and 11b fitted with optical fibers and provided on the system body 10 side, with connection end parts 32, 32a and 32b insertable thereinto and extractable therefrom of an optical fiber 31 provided on the sensor head 30 side, via adapters 20, 20a and 20b with built-in sleeves capable of keeping other ferrules coaxially in contact therewith on ends of ferrules 12, 12a and 12b with optical fibers 13, 13a and 13b of the connector housed therein. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a sensor head connection method and a sensor head connection device of an optical fiber sensor system suitable for use in, for example, an optical fiber SPR (Surface Plasmon Resonance) sensor system.

  In recent years, a sensor (SPR sensor) using surface plasmon resonance (SPR) has attracted attention. The SPR sensor is a sensor (refractive index sensor) that measures the refractive index using near-field optics, and can detect proteins, DNA, and antigen antibodies with high sensitivity, and is therefore applied in the fields of biotechnology and medicine.

  In addition, since the SPR sensor is sensitive to the surface state (refractive index) of the sensor, the reaction occurring on the sensor surface can be detected in real time, and the types and concentrations of components of the medium (gas, liquid, etc.) in contact with the sensor surface are different. Therefore, it is expected to be applied as a sensor for substance identification and substance concentration measurement.

  The measurement principle of the SPR sensor will be described with reference to FIG. In this SPR sensor, gold is deposited on the surface of the glass substrate 101 by vapor deposition or the like to form a metal thin film 102. Laser light is incident at an incident angle θ from the back surface of the glass substrate 101, and the amount of reflected light is measured. Measurement is performed with a light receiving element (not shown).

  When a medium 103 (refractive index n) made of an organic compound such as protein, peptide, DNA, hormone or the like is fixed as a sample to be measured on the metal thin film 102 of such an SPR sensor, the glass is irradiated by laser light. Surface plasmons are excited at the boundary surface between the metal thin film 102 and the medium 103 by an evanescent wave generated at the boundary surface between the substrate 101 and the metal thin film 102.

  At this time, when an antigen-antibody reaction occurs on the medium 103, the dielectric constant ε of the medium 103 changes, the wave number in the plane direction of the evanescent wave matches the wave number in the plane direction of the surface plasmon, and a resonance phenomenon occurs. Along with this, the resonance angle also changes.

  As the resonance phenomenon between the evanescent wave and the surface plasmon occurs and the resonance angle changes, the refractive index also changes. That is, since the reflected light abruptly attenuates only when the medium 103 reacts, the presence or absence of the reaction can be known by measuring the reflected light.

  As described above, the SPR sensor can monitor the antigen-antibody reaction in a non-label and in real time. By utilizing this, a sample is selectively mixed while flowing a solution on the surface of the SPR sensor, whereby a change in resonance angle can be measured over time to analyze an intermolecular interaction.

  In addition, when an arbitrary protein is immobilized on the metal thin film 102 and a ligand assay that acts on this receptor flows on the surface of the SPR sensor, the resonance angle changes greatly. By utilizing such a phenomenon, it is possible to investigate receptor / ligand pairs from various protein and compound groups and to analyze the reaction rate of the combination.

  However, since such an SPR sensor uses a two-dimensional thin film, the optical system for measurement becomes complicated, the apparatus becomes complicated and large, and accordingly there is a problem that it is necessarily expensive. .

  Therefore, recently, an SPR sensor using an optical fiber has been developed as a solution to such a problem. As an SPR sensor using such an optical fiber, there are a reflective type (for example, see Patent Document 1) and a transmission type (for example, see Patent Documents 2 and 3).

  FIG. 24 shows an example of a transmission type optical fiber SPR sensor. In this biosensor 110a, two types of optical fibers having different core diameters are connected, and a metal thin film layer is provided on the outer periphery of the optical fiber serving as a sensor portion. That is, a first optical fiber consisting of a core 111 and a clad 112 and a second optical fiber consisting of a core 113 and a clad 114 are prepared, and the first optical fiber is fused and connected to both ends of the second optical fiber. The metal thin film 115 is provided on the outer periphery of the fusion splicing portion and the second optical fiber.

  According to this configuration, when a sample to be measured is disposed on the metal thin film 115 and inspection light is incident on the optical fiber, an evanescent wave is generated at the boundary surface 116 between the clad 114 and the metal thin film 115, and the object to be measured is generated by the evanescent wave. Surface plasmons are generated at the interface between the sample and the metal thin film 115. A resonance phenomenon occurs due to the coincidence of these wave numbers, and the resonance angle changes. Since the refractive index also changes with this, the presence or absence of reaction can be known from this characteristic. Further, according to this configuration, there is an advantage that the biosensor can be realized by a simple and easy manufacturing method in addition to detecting the concentration of the sample to be measured from the change in the refractive index characteristics.

  FIG. 25 shows another example of a transmission type optical fiber SPR sensor. In this biosensor 110b, a part of the clad layer 112 of a long optical fiber is removed to expose the core 111, and a metal thin film 115 is provided on the surface of the core 111. Similarly to the biosensor 110a, the biosensor 110b also attenuates the reflected light intensity with respect to a predetermined incident angle due to the surface plasmon resonance phenomenon generated at the interface between the sample to be measured and the metal thin film 115. The refractive index of the sample to be measured can be known from the characteristics, and as a result, the presence or absence of the antigen-antibody reaction can be known.

  FIG. 26 shows still another example of the transmission type optical fiber SPR sensor. In this biosensor 120, a part of the cladding layer of the long optical fiber 121 is removed to expose the core, and the exposed core fiber part is covered with the metal layer 122 to form a detection part. Presence or absence of biochemical reaction in the sample using plasmon resonance excited by the metal layer 122 of the detection unit when a sample for biochemical reaction measurement is placed and laser light is incident from the end of the optical fiber 121 Is detected. According to this configuration, it is possible to accurately determine the presence or absence of a biochemical reaction with a simple structure.

  FIG. 27 shows an example of a reflective optical fiber SPR sensor. The biosensor 130 is an optical fiber composed of a core fiber portion 134 and a cladding layer 133 covering the outer periphery, and the outer periphery of the core fiber portion 134 exposed by removing the tip cladding layer 133 of the optical fiber is removed. Is provided with a metal layer 135. On the outer periphery of the metal layer 135, a sensitive dielectric layer 132 and a non-sensitive dielectric layer 131 that are sensitive to the detection target are further provided in parallel with the axial direction of the optical fiber.

According to this configuration, as in the transmission type sensor shown in FIGS. 24 to 26, by immobilizing an antigen or an antibody on the sensitive dielectric layer 132, plasmon resonance occurs when the sample to be tested reacts. Since the reflected light intensity changes, it is possible to know the refractive index of the sample to be measured from this change, and thus the presence or absence of the antigen-antibody reaction. In addition, there is an advantage that the sensor portion can be made smaller than the transmission type sensor.
Japanese Patent Application Laid-Open No. 11-223597 JP 2002-350335 A JP 2003-57175 A

  However, the conventional optical fiber SPR sensor as described above has the following problems.

  That is, the transmission-type biosensors 110a, 110b, and 120 shown in FIGS. 24 to 26 need to be inspected while maintaining the linear state of the sensor unit provided with the metal thin film 115, and the sensor unit becomes large. In addition, since a special measurement container that covers the sensor unit is required, the entire apparatus is increased in size.

  When the sensor portion is large in this way, for example, when it is desired to inspect a liquid sample in a test tube or when it is desired to be inserted into a human body for inspection, the sensor cannot be inserted and the range of use is limited.

  On the other hand, the reflection-type biosensor 130 shown in FIG. 27 detects the laser light reflected a plurality of times in the core fiber part 134, so that it is difficult to measure the light intensity, and how light absorption by plasmon resonance occurs. It is difficult to determine whether it occurs under various conditions.

  In addition, since a beam splitter, a coupler, or the like is required as a detection element for detecting the light output from the output end of the optical fiber, it is inevitable that the sensitivity is lowered due to light attenuation caused by using these detection elements. In addition, the entire apparatus cannot be reduced in size.

  In addition, in both the transmissive type and the reflective type, the sensor unit directly touches the object to be measured. Therefore, the sensor unit needs to be washed and reused every time it is used, or disposable.

  However, since the sensor unit must be cleaned each time it is used repeatedly, it is troublesome and inconvenient, and the cost of using the sensor unit only once is high. There is a risk that the operation of the entire system may be hindered.

  The present invention has been made in order to solve the above-described problems, and it is possible to dispose only the sensor head, thereby reducing the operation cost of the entire sensor system. It is an object of the present invention to provide a sensor head connection method and an apparatus therefor.

  A sensor head connection method for an optical fiber sensor system according to a first aspect of the present invention is a method for connecting a sensor head to an optical fiber sensor system, wherein an optical fiber connector provided on the system body side is connected to an optical fiber of the connector. An empty ferrule is attached to the tip of the ferrule containing the fiber via an adapter with a built-in sleeve that can be held against another ferrule coaxially, and the connection end of the optical fiber provided on the sensor head side to the empty ferrule And optically connected to the optical fiber accommodated in the ferrule of the connector.

  A sensor head connection method for an optical fiber sensor system according to claim 2 of the present invention is a method for connecting a sensor head to an optical fiber sensor system, wherein a pair of optical fiber connectors provided on the system main body side is connected to each of the connectors. A pair of empty ferrules are respectively attached to the tip of the ferrule containing the optical fiber of the connector through a sleeve built-in adapter that can be held in contact with another ferrule coaxially. A pair of connection end portions of the provided optical fiber are respectively inserted and optically connected to the optical fiber accommodated in the ferrule of the pair of connectors.

  A sensor head connection method for an optical fiber sensor system according to a third aspect of the present invention is the sensor head connection method for an optical fiber sensor system according to the second aspect, wherein the pair of connection end portions of the optical fiber provided on the sensor head side. Is separated into an incident light line from the system main body side to the sensor head side and an outgoing light line from the sensor head side to the system main body side.

  A sensor head connecting device for an optical fiber sensor system according to a fourth aspect of the present invention is a device for connecting a sensor head to an optical fiber sensor system, and an optical fiber connector provided on the system main body side is connected to an optical fiber of the connector. An empty ferrule capable of inserting and removing the connection end of the optical fiber provided on the sensor head side is attached to the tip of the ferrule containing the fiber via a sleeve built-in adapter that can hold another ferrule coaxially. It is characterized by.

  A sensor head connecting device for an optical fiber sensor system according to a fifth aspect of the present invention is the sensor head connecting device for an optical fiber sensor system according to the fourth aspect, wherein the flange member of the empty ferrule is provided on the sensor head side. A guide member is provided as a guide when the connection end of the optical fiber is inserted.

  A sensor head connecting device for an optical fiber sensor system according to a sixth aspect of the present invention is the sensor head connecting device for an optical fiber sensor system according to the fourth or fifth aspect, wherein the empty ferrule is provided on the sensor head side. The inserted optical fiber cable and the flange member of the empty ferrule at a position where the connection end of the optical fiber is inserted until its tip is optically connected to the optical fiber housed in the ferrule of the connector. Alternatively, a fixing member that detachably fixes the guide member is provided.

  A sensor head connecting device for an optical fiber sensor system according to a seventh aspect of the present invention is a device for connecting a sensor head to an optical fiber sensor system, and is connected to two connectors with optical fibers provided on the system body side. A pair of connection end portions of the optical fiber provided on the sensor head side can be inserted / removed via an adapter with a built-in sleeve that can coaxially hold another ferrule against the tip of the ferrule containing the optical fiber of each connector. It is characterized by the fact that each empty ferrule is attached.

  A sensor head connecting device for an optical fiber sensor system according to an eighth aspect of the present invention is the sensor head connecting device for an optical fiber sensor system according to the seventh aspect, wherein the sensor head is a sensor probe in which an optical fiber is bent in a U-shape. The pair of connection end portions are connected to both ends of the sensor probe.

  A sensor head connecting device for an optical fiber sensor system according to a ninth aspect of the present invention is the sensor head connecting device for an optical fiber sensor system according to the seventh aspect, wherein the flange member of the pair of empty ferrules is arranged on the sensor head side. Each is provided with a guide member that serves as a guide for inserting a pair of connection end portions of the provided optical fiber.

  A sensor head connecting device for an optical fiber sensor system according to a tenth aspect of the present invention is the sensor head connecting device for an optical fiber sensor system according to the seventh or ninth aspect, wherein the pair of empty ferrules is connected to the sensor head side. A pair of connecting end portions of the optical fiber provided at the position where the tip ends are optically connected to the optical fibers accommodated in the ferrules of the two connectors, respectively. A fixing member that detachably fixes the cable and the flange member of the pair of empty ferrules or the guide member is provided.

  As described above, the present invention provides a connector with an optical fiber provided on the system main body side, via a sleeve built-in adapter that can hold another ferrule coaxially against the tip of the ferrule that houses the optical fiber of the connector, Since an empty ferrule was attached, and the connection end of the optical fiber provided on the sensor head side was inserted into the empty ferrule so that it was optically connected to the optical fiber accommodated in the ferrule of the connector. Only the sensor head can be made disposable, thereby reducing the operation cost of the entire sensor system.

  Embodiments of the present invention will be described with reference to the drawings.

  1 to 7 show an embodiment of a sensor head connecting device of an optical fiber sensor system according to the present invention. The sensor head connecting device 1 of the optical fiber sensor system is a system main body 10 side as shown in FIG. The connection end portion 32 of the optical fiber 31 provided on the sensor head 30 side is connected to the connector 11 with the optical fiber provided in FIG.

  Therefore, the sensor head connecting device 1 of the optical fiber sensor system, as shown in FIG. 2 and FIG. 3, projects another ferrule on the connector 11 coaxially with the tip of the ferrule 12 that houses the optical fiber 13 of the connector 11. An empty ferrule 15 into which the connection end portion 32 of the optical fiber 31 can be inserted and removed is attached via the adapter 20 with a built-in sleeve that can be held against.

  That is, as shown in FIGS. 2 to 5, the adapter 20 with a built-in sleeve includes a cylindrical sleeve 21 having an inner diameter dimension that fits the outer diameter dimension of the ferrules 12 and 15 with a necessary minimum clearance, and the ferrule 12. , 15 and the metal pipe 22 having a total length slightly shorter than the total length when abutted against each other.

  The metal pipe 22 has openings 23 through which the ferrules 12 and 15 can be inserted at both ends with a relatively sufficient clearance. The diameter of the sleeve 21 is larger than the opening 23 between the openings 23 and 23. And a hollow cylindrical portion 24 having an inner diameter dimension substantially equal to.

  The sleeve 21 has an overall length that is slightly shorter than the length of the hollow portion 24 of the metal pipe 22, and the metal pipe 22 is configured to be insertable into two parts. Therefore, after accommodating the sleeve 21 in the hollow portion 24 with the metal pipe 22 broken, the adapter 20 with a built-in sleeve can be assembled by inserting the metal pipe 22 (see FIGS. 4 and 5).

  When the adapter with a built-in sleeve 20 is in an assembled state, the sleeve 21 is positioned substantially in the center without being biased to either end of the metal pipe 22, and the axis of the sleeve 21 substantially coincides with the axis of the metal pipe 22. In position.

  One of the outer diameter dimensions of the metal pipe 22 is divided into two parts, and is inserted into a cylindrical slot 14 formed around the ferrule 12 inside the connector 11 to be fixed to a predetermined depth. Only the portion is formed to be thin enough to be accommodated in the slot 14, but there is no such restriction on the outer diameter of the portion protruding from the slot 14.

  In summary, the dimensions of each part of the adapter 20 with a built-in sleeve are determined as follows.

  That is, as shown in FIG. 6, the ferrule 15 is inserted into the sleeve 21 from the end opposite to the end inserted into the slot 14 of the connector 11 until the flange member 16 hits the end of the metal pipe 22. 7, when inserted into the slot 14 of the connector 11 shown in FIG. 7, the ferrules 12 and 15 come into contact with each other immediately before reaching a predetermined depth, and then the ferrule 15 is slightly returned and the flange member 16 is moved to the metal pipe 22. At a position away from the end of the plate, it reaches a predetermined depth and is fixed (see FIG. 2).

  In this state, the ferrules 12 and 15 abut against each other and are in close contact with each other at substantially the center position of the sleeve 21.

  Further, the sensor head connection device 1 of the optical fiber sensor system includes a guide pipe 17 serving as a guide when the connection end portion 32 of the optical fiber 31 provided on the sensor head 30 side is inserted into the flange member 16 of the ferrule 15. ing.

  Further, as shown in FIG. 3, the sensor head connecting device 1 of the optical fiber sensor system has a ferrule 15 with a connection end 32 of an optical fiber 31 whose coating has been previously removed longer than the length of the ferrule 15, and the tip thereof is a connector. 11 is a fixing member that detachably fixes the cable 33 of the inserted optical fiber 31 and the guide pipe 17 of the ferrule 15 at a position where it is inserted until it is optically connected to the optical fiber 13 accommodated in the 11 ferrule 12. 25.

  As the fixing member 25, for example, a structure having a structure of holding by a spring force such as a clip can be used. However, the fixing member 25 is not limited to this, and the cable 33 of the optical fiber 31 and the guide pipe 17 (or flange member) of the ferrule 15 are used. 16) can be of any configuration suitable for detachably fixing.

  Further, the connector 11 with an optical fiber provided on the system main body 10 side can be directly attached to the housing of the system, for example. Generally, the other end of the optical fiber 13 accommodated in the ferrule 12 is used. A suitable connector 18 is attached to the connector 18 and the connector 18 is inserted into an input / output port of the system housing.

  Therefore, the standard of the connector 18 can be adapted to the input / output port of the system casing, while the standard of the connector 11 does not depend on the standard of the input / output port of the system casing.

  That is, as the connector 18, for example, an SMA connector having a ferrule diameter of 3.175 mm can be employed in addition to an FC connector having a ferrule diameter of 2.5 mm. On the other hand, as the connector 11, for example, an LC connector or a MU connector having a ferrule diameter of 1.25 mm can be employed in addition to an SC connector having a ferrule diameter of 2.5 mm.

  Since the ferrule 12 of the connector 11 is used in combination with the ferrule 15 into which the connection end 32 of the optical fiber 31 on the sensor head 30 side is inserted, it is preferable that the ferrule 12 is easy to handle and low in cost. Can be determined freely.

  Since the sensor head connecting device 1 of this optical fiber sensor system is configured as described above, an empty ferrule 15 attached to the connector with optical fiber 11 via the adapter 20 with a sleeve is provided along the guide pipe 17. The connection end 32 of the optical fiber 31 is inserted, and the end of the connection end 32 is optically connected to the optical fiber 13 accommodated in the ferrule 12 of the connector 11. The guide pipe 17 of the ferrule 15 is fixed with a fixing member 25.

  As a result, the optical fiber 13 on the system body 10 side and the optical fiber 31 on the sensor head 30 side are optically connected. As a result, the sensor head 30 is optically incorporated into the system body 10 and used. It becomes.

  Further, after using the sensor head 30 incorporated in the system main body 10, the sensor head 30 can be discarded by simply removing the fixing member 25 and removing the optical fiber 31 on the sensor head 30 side from the ferrule 15. That is, the sensor head 30 is disposable.

  FIGS. 8-15 shows other embodiment of the sensor head connection apparatus of the optical fiber sensor system by this invention, The sensor head connection apparatus 2 of this optical fiber sensor system uses except a pair of optical fiber, Since it is the same as the sensor head connecting device 1 of the optical fiber sensor system shown in FIGS. 1 to 7, the same parts are indicated by the same reference numerals used in FIGS. .

  The sensor head connecting device 2 of this optical fiber sensor system includes a pair of optical fiber 31 provided on the sensor head 30 side and a pair of connection end portions 32a, 11b provided on the system body 10 side. 32b is connected.

  That is, in the case of the sensor head connecting device 2 of this optical fiber sensor system, the sensor head 30 has a sensor probe 40 in which an optical fiber 31 is bent in a U shape, as shown in FIG. A pair of connection end portions 32a and 32b are connected to both ends.

  In other words, the sensor head 30 uses a single optical fiber 31 to form a sensor probe 40 bent in a U shape at substantially the center thereof, and protects the sensor probe 40 from being subjected to an external force that deforms the shape of the sensor probe 40. The integrated member 34 including the protection pipes 35a and 35b is configured to maintain the cables 33a and 33b of the optical fiber 31 extending from both ends of the sensor probe 40 in a parallel state close to each other.

  The sensor probe 40 curved in such a U-shape is suitable as a sensor (SPR sensor) using surface plasmon resonance (SPR), and therefore, the sensor head connection of this optical fiber sensor system. The device 2 is particularly suitable for use in an optical fiber SPR sensor system.

  In order to connect the pair of connection ends 32a and 32b of the optical fiber 31 provided on the sensor head 30 side to the system main body 10 side, the sensor head connection device 2 of the optical fiber sensor system is shown in FIGS. As shown in FIG. 6, the adapter 20a with a built-in sleeve that can hold another ferrule coaxially against and hold the ferrules 12a and 12b accommodating the optical fibers 13a and 13b of the connectors 11a and 11b with the two connectors 11a and 11b. , 20b, the empty ferrules 15a and 15b into which the connection ends 32a and 32b of the optical fiber 31 can be inserted and removed are attached.

  As shown in FIGS. 10 to 13, the adapters 20 a and 20 b with a built-in sleeve are cylindrical sleeves having an inner diameter dimension that fits with an outer diameter dimension of the ferrules 12 a and 15 a or the ferrules 12 b and 15 b with a minimum clearance. 21a and 21b, and metal pipes 22a and 22b having a total length slightly shorter than the total length when the ferrules 12a and 15a or the ferrules 12b and 15b face each other.

  The metal pipes 22a and 22b have openings 23a and 23b through which the ferrules 12a and 15a or the ferrules 12b and 15b can be inserted with a relatively sufficient clearance at both ends, and between the openings 23a and 23a or between the openings 23b and 23b. There are provided cylindrical hollow portions 24a and 24b having a larger diameter than the openings 23a and 23b and an inner diameter dimension substantially equal to the outer diameter dimension of the sleeves 21a and 21b.

  The sleeves 21a and 21b have an overall length slightly shorter than the lengths of the hollow portions 24a and 24b of the metal pipes 22a and 22b, and the metal pipes 22a and 22b are configured to be inserted into two parts. . Therefore, after accommodating the sleeves 21a and 21b in the hollow portions 24a and 24b in a state where the metal pipes 22a and 22b are broken, the adapters 20a and 20b with built-in sleeves can be assembled by inserting the metal pipes 22a and 22b ( (See FIGS. 4 and 5).

  When the sleeve built-in adapters 20a and 20b are in the assembled state, the sleeves 21a and 21b are positioned substantially in the center without being biased to either end of the metal pipes 22a and 22b, and the axes of the sleeves 21a and 21b are The pipes 22a and 22b are in positions substantially coincident with the axis.

  One of the outer diameters of the metal pipes 22a and 22b is divided into two parts, and is inserted into the cylindrical slots 14a and 14b formed around the ferrules 12a and 12b inside the connectors 11a and 11b and fixed to a predetermined depth. Therefore, only the predetermined depth is formed to be thin enough to be accommodated in the slots 14a and 14b, but there is no such restriction on the outer diameter of the portion protruding from the slots 14a and 14b.

  In summary, the dimensions of the respective parts of the adapters 20a and 20b with a built-in sleeve are determined as follows.

  That is, as shown in FIG. 14, the ferrules 15a and 15b are connected to the flange members 16a and 16b of the metal pipes 22a and 22b from the ends opposite to the ends inserted into the slots 14a and 14b of the connectors 11a and 11b. When the sleeve is inserted into the sleeves 21a and 21b until it hits the end, and then inserted into the slots 14a and 14b of the connectors 11a and 11b shown in FIG. After the contact, the ferrules 15a and 15b are slightly returned and the flange members 16a and 16b reach a predetermined depth and are fixed at positions away from the ends of the metal pipes 22a and 22b (see FIG. 10). .

  In this state, the ferrules 12a and 15a or the ferrules 12b and 15b are in contact with each other and are in close contact with each other at substantially the center position of the sleeves 21a and 21b.

  The sensor head connection device 2 of the optical fiber sensor system includes a guide for inserting the connection ends 32a and 32b of the optical fiber 31 provided on the sensor head 30 side into the flange members 16a and 16b of the ferrules 15a and 15b. Guide pipes 17a and 17b are provided.

  Further, as shown in FIG. 11, the sensor head connecting device 2 of the optical fiber sensor system includes ferrules 15a and 15b, connection end portions 32a and 32b of an optical fiber 31, and ferrules 12a and 12b whose connectors are connectors 11a and 11b. The cables 33a and 33b of the inserted optical fiber 31 and the guide pipes 17a and 17b of the ferrules 15a and 15b can be attached and detached at the position where they are inserted until they are optically connected to the optical fibers 13a and 13b accommodated in the cable. Fixing members 25a and 25b for fixing are provided.

  As the fixing members 25a and 25b, for example, a structure that is sandwiched by a spring force such as a clip can be used. However, the fixing members 25a and 25b are not limited thereto, and the cables 33a and 33b of the optical fiber 31 and the guides of the ferrules 15a and 15b. The pipe 17a, 17b (or the flange member 16a, 16b) can be of any configuration suitable for detachably fixing.

  Furthermore, the connectors 11a and 11b with optical fibers provided on the system main body 10 side can be directly attached to the housing of the system, for example, but are generally accommodated in the ferrules 12a and 12b. Appropriate connectors 18a and 18b are attached to the other ends of the optical fibers 13a and 13b, and the connectors 18a and 18b are inserted and attached to the input / output ports of the system casing.

  Therefore, the standard of the connectors 18a and 18b can be adapted to the input / output port of the system casing, while the standard of the connectors 11a and 11b does not depend on the standard of the input / output ports of the system casing. .

  That is, as the connectors 18a and 18b, for example, an SMA connector having a ferrule diameter of 3.175 mm can be employed in addition to an FC connector having a ferrule diameter of 2.5 mm. On the other hand, as the connectors 11a and 11b, for example, an SC connector having a ferrule diameter of φ2.5 mm, an LC connector having a ferrule diameter of φ1.25 mm, or an MU connector can be employed.

  Since the ferrules 12a and 12b of the connectors 11a and 11b are used in combination with the ferrules 15a and 15b for inserting the connection ends 32a and 32b of the optical fiber 31 on the sensor head 30 side, the handling is easy and the cost is low. Those are preferable, and can be determined freely from such a viewpoint.

  Since the sensor head connecting device 2 of this optical fiber sensor system is configured as described above, the empty ferrules 15a and 15b attached to the connectors 11a and 11b with optical fibers via the adapters 20a and 20b with built-in sleeves are used. The connection ends 32a and 32b of the optical fiber 31 are inserted along the guide pipes 17a and 17b, and the tips of the connection ends 32a and 32b are inserted into the ferrules 12a and 12b of the connectors 11a and 11b. The cables 33a and 33b of the optical fiber 31 and the guide pipes 17a and 17b of the ferrules 15a and 15b are fixed by fixing members 25a and 25b at a position optically connected to 13b.

  Thus, the optical fibers 13a and 13b on the system body 10 side and the optical fiber 31 on the sensor head 30 side are optically connected. As a result, the sensor head 30 is optically incorporated into the system body 10 and used. The Rukoto.

  Further, after using the sensor head 30 incorporated in the system main body 10, the sensor head 30 can be disposable by removing the optical fiber 31 on the sensor head 30 side from the ferrules 15a and 15b simply by removing the fixing members 25a and 25b. Can do. That is, the sensor head 30 is disposable.

  Here, an embodiment of the sensor probe 40 when the sensor head connection device 2 of the optical fiber sensor system is applied to an optical fiber SPR sensor system, that is, a method for manufacturing the SPR sensor probe 41 shown in FIG. Explanation will be made with reference to FIG.

  In this case, as the optical fiber 31 used for the SPR sensor probe 41, either a single mode optical fiber (SMF) or a multimode optical fiber (MMF) can be used. In addition, any type of optical fiber such as quartz fiber, multicomponent fiber, plastic clad silica fiber (PCS), all plastic fiber, etc. can be used. Further, any graded index type fiber, step index type fiber, or optical fiber having a refractive index profile can be used.

  For example, in the case of a silica-based fiber, as shown in FIG. 18A, the core 43 is surrounded by a clad 44 and the clad 44 is surrounded by a coating 45.

  In order to manufacture the SPR sensor probe 41 using such a silica-based fiber, first, as shown in FIG. 18B, the coating 45 is removed by a required length to expose the clad 44. As a method for removing the coating 45, for example, the coating 45 is removed by immersing in an appropriate chemical solution that dissolves the coating 45, or mechanically removed using a tool such as a nipper.

  Next, as shown in FIG. 18 (c), the exposed outer periphery of the clad 44 is softened and melted using, for example, a gas burner, and the quartz fiber is bent into a U-shape to bend to approximately 180 °. A portion 46 is formed.

  Next, as shown in FIG. 18D, most of the cladding 44 is removed by immersing the curved portion 46 in, for example, a hydrofluoric acid aqueous solution for a certain period of time, as shown in FIG. In addition, the core 43 is substantially exposed.

  After that, as shown in FIG. 18F, a metal thin film 47 made of a conductive material such as gold Au or silver Ag is formed on the exposed surface of the core 43 with a thickness of 0.1 μm or less. As a method for forming the conductive metal thin film 47, for example, a vacuum deposition method, a sputtering method, a CVD method, a thermal oxidation method, or the like can be used.

  For example, when the SPR sensor probe 41 is manufactured using a plastic clad silica fiber (PCS), although not shown, first, the clad 44 is decomposed and disappeared by heating the plastic clad silica fiber. Then, the exposed core 43 is softened and melted and bent into a U shape, and then a conductive metal thin film 47 is formed on the exposed surface of the core 43 of the bending portion 46. Note that the step of decomposing and disappearing the clad 44 and the step of softening and melting the core 43 can be performed simultaneously.

  In addition, another embodiment of the sensor probe 40 when the sensor head connection device 2 of the optical fiber sensor system is applied to an optical fiber SPR sensor system, that is, a method for manufacturing the SPR sensor probe 42 shown in FIG. 17 will be described. .

  In this case, in order to manufacture the SPR sensor probe 42 using the silica-based fiber, the length of removing the coating 45 is made longer than that of the SPR sensor probe 41, and the almost central portion of the exposed cladding 44 is softened and melted. The curved portion 46 is formed, and the curved portion 46 and the linear portion 48 that follows the curved portion 46 are immersed in, for example, a hydrofluoric acid aqueous solution for a certain period of time to remove most of the clad 44, and to the exposed surface of the core 43. The SPR sensor probe 42 can be obtained by forming the conductive metal thin film 47.

  Similarly, when the SPR sensor probe 42 is manufactured using plastic clad silica fiber (PCS), the length of the cladding 44 to be decomposed and lost is longer than that of the SPR sensor probe 41, and the exposed core 43 is almost at the center. The portion is softened and melted and bent into a U-shape, and a conductive metal thin film 47 is formed on the exposed surface of the core 43 of the curved portion 46 and the subsequent linear portion 48, thereby obtaining the SPR sensor probe 42. be able to.

  FIG. 19 shows an example in which the sensor head 30 using the SPR sensor probes 41 and 42 thus manufactured is connected to the system body 10 of the optical fiber SPR sensor system to constitute a refractive index measuring device.

  The sensor head 30 and the system main body 10 are connected to the optical fiber 31 on the sensor head 30 side (that is, the SPR sensor probes 41 and 42) and the system main body 10 side via the sleeve built-in adapters 20a and 20b. This is realized by optically connecting the optical fibers 13a and 13b.

  This refractive index measuring device (optical fiber SPR sensor system) 50 includes a white light source 51 and a spectroscope 52 to which the other end connector 18a of one optical fiber 13a on the system body 10 side is connected, and the other on the system body 10 side. A light receiving element (photomal) 53 and a measurement PC (personal computer) 54 to which the other end connector 18b of the optical fiber 13b is connected are provided.

  The white light source 51 outputs light having a wavelength of 400 to 900 nm, and the spectroscope 52 separates the output wavelength of the white light source 51.

  Since one end 32a of the optical fiber 31 on the sensor head 30 side is optically connected to one end of the optical fiber 13a, the light output from the white light source 51 and dispersed by the spectroscope 52 is light An optical fiber 13b that enters the one connection end 32a of the optical fiber 31 from the fiber 13a, passes through the SPR sensor probes 41 and 42, and is optically connected to the other connection end 32b of the optical fiber 31. And exits from the other end.

  The light receiving element 53 converts the transmitted light intensity transmitted through the core 43 of the SPR sensor probes 41 and 42 into an electric signal, and the measurement PC 54 has an electric signal of the transmitted light intensity with respect to the wavelength of the incident light. Are stored in association with each other, and output intensity adjustment of the white light source 51, control of the light receiving element 53, storage processing, data processing, and the like are performed.

  FIG. 20 shows the results of measuring samples to be measured having different concentrations using the SPR sensor probe 41 using the refractive index measuring device (optical fiber SPR sensor system) 50 shown in FIG. That is, FIG. 20 is an absorption curve obtained by measuring the intensity of outgoing light with respect to incident light (wavelength) in each aqueous solution using the spectral intensity (a) in the air as a reference.

  The concentration of each aqueous solution is (b) glycerol concentration 0% (pure water), (c) glycerol concentration 10%, (d) glycerol concentration 20%, (e) glycerol concentration 30%, (f) glycerol concentration 40%. is there.

  The SPR sensor probe 41 made of plastic clad silica fiber (PCS) was immersed in this glycerin aqueous solution, and the light emitted from the white light source 51 was incident from one end of the optical fiber 31 and propagated through the core 43.

  In the SPR sensor probe 41 immersed in the glycerin aqueous solution, the refractive index inside the core 43 changes due to the change in the dielectric constant of the metal thin film 47 due to the reaction between the aqueous solution and the metal thin film 47. The emitted light was detected by the light receiving element 53, and the intensity of the emitted light with respect to the incident light was measured. At this time, the wavelength of the light output from the white light source 51 was varied between 400 and 900 nm, and the intensity of light emitted from the optical fiber output end corresponding to this wavelength change was measured.

  As a result, as shown in FIG. 20, when (b) the glycerin concentration was 0%, attenuation of the light intensity was observed from around the wavelength of 610 nm, and the light intensity was the lowest around the wavelength of 630 nm. In the case of (c) glycerin concentration of 10%, the light intensity was lowest at a wavelength of about 650 nm. In the case of (d) a glycerin concentration of 20%, the light intensity was the lowest in the vicinity of a wavelength of 670 nm. In addition, (e) When the glycerin concentration was 30%, the light intensity was the lowest in the vicinity of the wavelength of 700 nm. Furthermore, (f) When the glycerin concentration was 40%, the light intensity was lowest in the vicinity of a wavelength of 750 nm.

  From the above results, it was confirmed that the maximum resonance wavelength shifts to the longer wavelength side as the concentration increases. That is, it was confirmed that the absorption peak shifted to the long wavelength side corresponding to the refractive index difference.

  When such an SPR sensor probe 41 is actually used, a spectrophotometric curve measured at a known concentration is stored in a storage device in advance, and when an aqueous solution of unknown concentration is measured, the attenuation characteristics and the measured characteristics are expressed. Compare and select matching properties from the spectrophotometric curve. From the degree of coincidence or difference, the concentration of the aqueous solution whose concentration is unknown can be specified.

  FIG. 21 shows the results of measuring samples to be measured having different concentrations using the SPR sensor probe 42 instead of the SPR sensor probe 41 using the refractive index measuring device (optical fiber SPR sensor system) 50 shown in FIG. .

  As shown in FIG. 21, in the case of the SPR sensor probe 42 in which the linear portion 48 is provided for a certain length (for example, 9 mm length) following the curved portion 46, the SPR sensor probe 41 of only the curved portion 46 without the linear portion 48 is provided. In comparison, the spectrophotometric curve was generally shifted downward (lower light intensity), and each light intensity curve was characterized.

  That is, in the process of rising from the vicinity beyond the peak, the difference from the peak is large. When focusing on (f) glycerin 40% in particular, (f) glycerin 40% in FIG. 20 has a gradual change in the curve and no difference between the peak peak and the following points. For 40%, the peak is clarified with a large difference from the peak top to the subsequent peak. This can be said to be evidence that the sensitivity of the SPR sensor probe 42 is higher than that of the SPR sensor probe 41.

  Further, as a comparative example of the spectrophotometric curves of the SPR sensor probes 41 and 42 shown in FIGS. 20 and 21, the same measurement was performed using the same aqueous solution in the conventional transmission type sensor 110b. The result is shown in FIG.

  As can be seen from the spectrophotometric curve of FIG. 22, the light intensity on the peak short wavelength side of each curve is the same curve and is not characterized. Therefore, for example, when a monochromatic light source is used, it is considered that it is quite difficult to determine the density with a conventional sensor.

  That is, in the case of the SPR sensor probe 42 shown in FIG. 21, when light having a monochromatic light source wavelength of 550 nm is incident, (f) with 40% glycerin, the transmitted light intensity with a light intensity of 0.85 is emitted from the emission end. e) When glycerin is 30%, a transmitted light intensity with a light intensity of 0.80 is emitted from the exit end of the optical fiber. (d) When glycerin is 20%, a transmitted light intensity with a light intensity of 0.75 is emitted from the exit end of the optical fiber. Since it is emitted, the concentration of the aqueous solution can be specified by the emitted light intensity.

  On the other hand, in the conventional sensor 110b shown in FIG. 22, when a monochromatic light source wavelength of 550 nm is incident, the intensity of emitted light is about 0.8 regardless of the aqueous solution, and there is almost no difference. Therefore, it is almost impossible to specify the density, and it can be said that it is difficult to specify the density with the monochromatic laser light source.

  In the above-described embodiment, the sensor head connecting device particularly suitable for use in the optical fiber SPR sensor system has been described. However, the present invention is not limited to this, and optical fibers for various uses other than the SPR sensor system. It can be widely applied to sensor systems.

  In the above embodiment, when the sensor head 30 is used, the empty ferrules in which the connection ends 32, 32a, 32b of the optical fiber 31 on the sensor head 30 side are attached to the connectors 11, 11a, 11b with optical fibers are used. While the sensor head 30 is used, the optical fiber 31 on the sensor head 30 side is removed from the ferrules 15, 15a, 15b and the sensor head 30 is disposable.

  That is, the sensor head 30 is disposable. In this sense, the ferrules 15, 15 a, 15 b that should be attached and fixed to the connection ends 32, 32 a, 32 b of the optical fiber 31 on the sensor head 30 side are originally connected to the optical fiber connectors 11, 11 a, 11 b side. Such a configuration that can be used repeatedly as many times as possible is the best cost measure.

  However, the present invention is not limited to the above configuration. That is, for example, the sensor head 30 can be configured by attaching and fixing the ferrules 15, 15a, and 15b to the connection end portions 32, 32a, and 32b of the optical fiber 31 on the sensor head 30 side in advance. At this time, the fixing members 25, 25a and 25b are unnecessary, and the guide pipes 17, 17a and 17b are also unnecessary.

  In this case, when the sensor head 30 is used, the sleeves of the connectors 11, 11a, 11b with optical fibers are used until the ferrules 15, 15a, 15b on the sensor head 30 side are brought into close contact with the ferrules 12, 12a, 12b. What is necessary is just to insert in the built-in adapter 20, 20a, 20b.

  This method is disadvantageous compared to the above embodiment in that when the sensor head 30 is disposable, the ferrules 15, 15a, 15b on the sensor head 30 side are also disposable. On the other hand, since the ferrules 15, 15a, 15b are mounted and fixed in advance, the tips of the connection ends 32, 32a, 32b of the optical fiber 31 can be polished.

  As a result, the optical connection characteristics between the distal ends of the connection ends 32, 32a, 32b of the fiber 31 on the sensor head 30 side and the optical fibers 13, 13a, 13b on the system body 10 side are more reliable than those in the above embodiment. To improve. Therefore, it is particularly suitable for application to an optical fiber sensor system that requires high accuracy in the optical connection characteristics between the system body 10 side and the sensor head 30 side.

  As is apparent from the above description, the sensor head connecting devices 1 and 2 of the optical fiber sensor system according to the present invention can make only the sensor head 30 disposable, thereby reducing the operation cost of the entire sensor system. can do.

  In addition, the sensor head connecting devices 1 and 2 of the optical fiber sensor system according to the present invention have a smaller sensor portion than the conventional transmission type, and the configuration of the entire system can be reduced and simplified.

  Furthermore, a beam splitter, a coupler, etc. are unnecessary compared with the conventional reflective type, and the measurement sensitivity of the entire system can be increased. In addition, the configuration in which only the sensor head 30 is disposable is simple, and the cost required for making the sensor head 30 disposable can be reduced.

It is a block diagram which shows one Embodiment of the sensor head connection apparatus of the optical fiber sensor system by this invention. It is an expanded sectional view of the principal part of the thing of FIG. It is an expanded sectional view which shows the assembly state of the thing of FIG. It is an expanded sectional view of an adapter with a built-in sleeve. It is an assembly sectional view of an adapter with a built-in sleeve. It is sectional drawing which shows the assembly state which inserted the empty ferrule in the adapter with a built-in sleeve. It is sectional drawing of the connector which inserts a sleeve built-in adapter. It is a block diagram which shows other embodiment of the sensor head connection apparatus of the optical fiber sensor system by this invention. It is a block diagram which shows the sensor head of the thing of FIG. It is an expanded sectional view of the principal part of the thing of FIG. It is an expanded sectional view which shows the assembly state of the thing of FIG. It is an expanded sectional view of an adapter with a built-in sleeve. It is an assembly sectional view of an adapter with a built-in sleeve. It is sectional drawing which shows the assembly state which inserted the empty ferrule in the adapter with a built-in sleeve. It is sectional drawing of the connector which inserts a sleeve built-in adapter. It is sectional drawing which shows an example of a SPR sensor probe. It is sectional drawing which shows the other example of a SPR sensor probe. It is process drawing which shows the manufacturing method of the SPR sensor probe of FIG. It is a schematic block diagram which shows an example of the refractive index measuring apparatus using the SPR sensor probe of FIG. 16, FIG. It is a graph which shows the spectral intensity curve which measured the to-be-measured sample from which a density | concentration differs using the SPR sensor probe of FIG. It is a graph which shows the spectral intensity curve which measured the to-be-measured sample from which a density | concentration differs using the SPR sensor probe of FIG. It is a graph which shows the spectral intensity curve which measured the to-be-measured sample from which a density | concentration differs using the conventional SPR sensor probe. It is a schematic diagram for demonstrating a SPR phenomenon. It is sectional drawing which shows an example of the conventional transmission type sensor. It is sectional drawing which shows the other example of the conventional transmission type sensor. It is sectional drawing which shows the other example of the conventional transmission type sensor. It is sectional drawing which shows an example of the conventional reflection type sensor.

Explanation of symbols

1, 2 Sensor head connection device 10 of optical fiber sensor system System body 11, 11a, 11b Connector (connector with optical fiber)
12, 12a, 12b ferrule (ferrule containing optical fiber)
13, 13a, 13b Optical fibers 14, 14a, 14b Slots 15, 15a, 15b Ferrule (empty ferrule)
16, 16a, 16b Flange members 17, 17a, 17b Guide pipes 18, 18a, 18b Connectors 20, 20a, 20b Sleeve built-in adapters 21, 21a, 21b Sleeves 22, 22a, 22b Metal pipes 23, 23a, 23b Openings 24, 24a , 24b Hollow portions 25, 25a, 25b Fixing member 30 Sensor head 31 Optical fibers 32, 32a, 32b Connection end portions 33, 33a, 33b Cable 34 Integrated member 35a, 35b Protection pipe 40 Sensor probe 41, 42 SPR sensor probe 43 Core 44 Cladding 45 Covering 46 Bending part 47 Conductive metal thin film 48 Straight line part 50 Refractive index measuring device (optical fiber SPR sensor system)
51 White light source 52 Spectrometer 53 Light receiving element (photomal)
54 PC for measurement (personal computer)

Claims (10)

A method of connecting a sensor head to an optical fiber sensor system, comprising:
An empty ferrule is attached to a connector with an optical fiber provided on the system main body side via an adapter with a built-in sleeve that can hold another ferrule coaxially against the tip of the ferrule that contains the optical fiber of the connector,
A sensor of an optical fiber sensor system, wherein a connection end of an optical fiber provided on the sensor head side is inserted into the empty ferrule and optically connected to an optical fiber accommodated in the ferrule of the connector Head connection method. A method of connecting a sensor head to an optical fiber sensor system, comprising:
A pair of empty ferrules is connected to the pair of connectors with optical fibers provided on the system main body side through an adapter with a built-in sleeve that can hold another ferrule coaxially against the tip of the ferrule containing the optical fiber of each connector. Each attached,
A pair of connection end portions of optical fibers provided on the sensor head side are respectively inserted into the pair of empty ferrules, and optically connected to the optical fibers housed in the ferrules of the pair of connectors, Sensor head connection method for optical fiber sensor system.   The pair of connection ends of the optical fiber provided on the sensor head side are separated into an incident light line from the system main body side to the sensor head side and an outgoing light line from the sensor head side to the system main body side. The sensor head connecting method of the optical fiber sensor system according to claim 2. An apparatus for connecting a sensor head to an optical fiber sensor system,
An optical fiber provided on the sensor head side through an adapter with a built-in sleeve that can hold another ferrule coaxially with the tip of the ferrule that accommodates the optical fiber of the connector provided on the connector with the optical fiber provided on the system main body side Attached an empty ferrule that can be inserted and removed
A sensor head connecting device for an optical fiber sensor system.   5. The sensor of the optical fiber sensor system according to claim 4, further comprising a guide member serving as a guide for inserting a connection end of an optical fiber provided on the sensor head side into the flange member of the empty ferrule. Head connection device.   The inserted optical fiber is inserted into the empty ferrule at a position where the connecting end of the optical fiber provided on the sensor head side is inserted until the tip is optically connected to the optical fiber accommodated in the ferrule of the connector. 6. A sensor head connecting device for an optical fiber sensor system according to claim 4, further comprising a fixing member that detachably fixes the cable of said empty cable and a flange member or said guide member of said empty ferrule. . An apparatus for connecting a sensor head to an optical fiber sensor system,
To the sensor head side through the adapter with a built-in sleeve that can hold another ferrule coaxially against the tip of the ferrule that houses the optical fiber of each connector, on the connector with two optical fibers provided on the system body side A pair of empty ferrules capable of inserting and removing a pair of connection end portions of the provided optical fiber were respectively attached.
A sensor head connecting device for an optical fiber sensor system.   8. The sensor head of the optical fiber sensor system according to claim 7, wherein the sensor head has a sensor probe in which an optical fiber is bent in a U shape, and the pair of connection end portions are connected to both ends of the sensor probe. Connected device.   8. The light according to claim 7, further comprising a guide member serving as a guide when the pair of connection end portions of the optical fiber provided on the sensor head side is inserted into the flange member of the pair of empty ferrules. Sensor head connection device for fiber sensor system.   Inserted into the pair of empty ferrules is a pair of connection end portions of optical fibers provided on the sensor head side until their tips are optically connected to the optical fibers housed in the ferrules of the two connectors. 8. A fixing member that detachably fixes the inserted pair of optical fiber cables and the flange member or the guide member of the pair of empty ferrules at a position. 10. A sensor head connecting device for an optical fiber sensor system according to claim 9.

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