CN209821048U

CN209821048U - Selectable dual-channel optical fiber sensor

Info

Publication number: CN209821048U
Application number: CN201920583493.4U
Authority: CN
Inventors: 葛益娴; 顾钦顺; 李玲; 张鹏
Original assignee: Nanjing University of Information Science and Technology
Current assignee: Nanjing University of Information Science and Technology
Priority date: 2019-04-26
Filing date: 2019-04-26
Publication date: 2019-12-20
Anticipated expiration: 2029-04-26

Abstract

The utility model discloses an alternative binary channels fiber sensor belongs to optical fiber sensing technical field, including single mode fiber core, set up single mode fiber cladding in single mode fiber core periphery the upside and the downside of single mode fiber cladding all set up and throw the mill flour region, set up TIO in the throwing mill flour region of upside₂An ITO-AU composite film provided in the lower polished surface region. The utility model adopts TIO₂the-AU composite film and the ITO-AU composite film replace the traditional single-layer metal film, not only the sensitivity of the original gold film in the spr structure is kept, but also the sensitivity of the original gold film can be increased to a certain degreeDegree; the utility model discloses a two resonance troughs that the sensor produced have obvious difference to make it can be more directly perceived bright when being utilized to observe, can play very profitable result in various detection areas because of its high sensitivity and convenient validity.

Description

Selectable dual-channel optical fiber sensor

Technical Field

The utility model belongs to the technical field of the optical fiber sensing, concretely relates to optional binary channels optical fiber sensor.

Background

Surface plasmon resonance was observed in optical experiments by wood and other research teams in the early 20 th century, and then comes into the human sight. The plasmon resonance phenomenon is a physical optical phenomenon occurring at the interface between light and an electrolyte and caused by the resonance action of free electrons under certain conditions.

In 1968, Otto indicated that SPR effects would occur under specific conditions, and given corresponding conditions immediately after Krestchman in 1971 modified the structure of an Otto-type prism SPR sensor by using a prism and a metal film to excite the surface plasmon resonance phenomenon. In 1992, the plasmon resonance sensor realized a new breakthrough, and r.c. jorgenson researched the plasmon resonance sensor using an optical fiber instead of a prism, so that the optical fiber SPR technology came from this fact.

Fiber SPR technology is a technology that effectively combines technology with optical fibers. The spr (surface plasma resonance) technique is a technique for detecting a slight change in the surface of a medium by using an optical principle. The optical fiber SPR consists of a fiber core, a sensitive film and an environment medium 3-layer structure, light is transmitted in the optical fiber and can be totally reflected, evanescent waves can be generated in the process of total reflection, free electrons on the surface of metal can be excited, and surface plasma waves (surface plasma Wave SPW) can be generated. When a certain condition is met, the surface plasmon and the evanescent wave resonate, and the energy of the incident light is coupled into the surface plasmon, so that the amplitude, phase and other information of the reflected light are changed, and the magnitude of the change is generally related to the optical characteristics of the surrounding medium.

At present, research based on the optical fiber SPR sensing technology mainly focuses on the design and development of a novel structure SPR sensor based on an optical fiber, and diversified applications such as higher precision, strong universality and multiple channels are expected to be obtained.

The application publication No. CN109187440A discloses a single-mode-few-mode/multi-mode fiber SPR sensor based on mode excitation, which comprises a single-mode fiber, a mode excitation element, a few-mode/multi-mode fiber and a coating sensitive element, wherein the single-mode fiber, the mode excitation element, the few-mode/multi-mode fiber and the coating sensitive element are arranged in a quartz tube; the mode excitation element is a staggered welding area formed by staggered welding of the other end of the single-mode fiber and the other end of the few-mode/multi-mode fiber, and the mode excitation element adopts offset coupling excitation as an excitation element; the coating sensitive element is an SPR sensing area which is positioned on the few-mode/multimode fiber and is formed by a section of core with a stripped cladding behind the dislocation welding area and a metal film coated on the periphery of the section of core.

The application publication number is CN108303399A, which discloses a twin-core optical fiber double-channel surface plasmon resonance sensor, which can effectively improve the sensing efficiency, obtain two independent sensing spectra through an SPR sensor, and simultaneously can complete single-channel sensing according to independent selection, thereby solving the problem that two independent sensing spectra cannot be obtained during double-channel measurement, expanding the selection range of different requirements during double-channel sensing, and realizing the combination of the single-channel sensor and the double-channel sensor.

SUMMERY OF THE UTILITY MODEL

Utility model purpose: an object of the utility model is to provide a selective binary channels fiber sensor not only can realize the binary channels under same measuring environment and measure, makes the data that record more accurate simultaneously, has small, longe-lived, and sensitivity is strong, advantages such as reuse degree height.

The technical scheme is as follows: in order to achieve the above purpose, the utility model adopts the following technical scheme:

a selectable dual-channel optical fiber sensor comprises a single-mode optical fiber core, wherein a single-mode optical fiber cladding is arranged on the periphery of the single-mode optical fiber core, the upper side and the lower side of the single-mode optical fiber cladding are both provided with a polishing surface area, and the polishing surface area on the upper side is provided with a TIO₂An ITO-AU composite film provided in the lower polished surface region.

Further, in the TIO₂-AU composite membrane comprising TIO₂Film layer and first gold film(ii) a The ITO-AU composite film comprises an ITO film layer and a second gold film.

Further, the TIO₂The thickness of the film layer is 15 nm; the thickness of the ITO film layer is 10 nm.

Further, the thickness of the first gold film is 50 nm; the thickness of the second gold film is 50 nm.

Further, the first gold film is arranged on the TIO₂Between the film layer and the polishing surface area on the upper side; the second gold film is arranged between the ITO film layer and the polishing surface area on the lower side.

Further, the length of the groove of the polishing and grinding surface area is 8 mm.

Further, the distance between the cladding of the single-mode fiber in the polished surface area and the core of the single-mode fiber is 500 nm.

Based on TIO₂The preparation method of the side edge polishing type double-channel SPR sensor of the-AU composite membrane and the ITO-AU composite membrane comprises the following steps:

manufacturing a side edge polishing optical fiber: firstly, removing a coating layer at a position where polishing and grinding are needed on two sides of a single-mode optical fiber, exposing a bare optical fiber with the length of about 30mm, cleaning the bare optical fiber, fixing the bare optical fiber on a clamp of a platform, adjusting the height and tension of a polishing and grinding wheel, setting polishing and grinding parameters at the upper end of the optical fiber, and polishing and grinding. And then, turning the position of the optical fiber and fixing the optical fiber on a platform clamp to set polishing parameters and polish the optical fiber, and finally cleaning the polished optical fiber and fixing the polished optical fiber on a glass slide.

TIO₂Manufacturing of-AU composite film and ITO-AU composite film: sputtering a layer of gold film with the thickness of about 50nm on the upper and lower polishing and grinding surfaces respectively by a film thickness monitor by adopting a direct current magnetron sputtering method, and sputtering a layer of 15nmTIO on the gold film plated on the upper side by the same direct current magnetron sputtering method₂Formation of TIO₂AU composite membrane. And sputtering a layer of ITO with the thickness of 15nm on the upper surface of the gold film plated on the lower side by a direct current magnetron sputtering method to form the ITO-AU composite film.

Has the advantages that: compared with the prior art, the utility model discloses an alternative binary channels fiber sensor adopts TIO₂-AU composite film and ITO-AU composite film replacing traditional oneThe single-layer metal film not only keeps the sensitivity of the original gold film in an spr structure, but also can increase the sensitivity to a certain degree; the sensor of traditional single channel its sensitivity and figure of merit can decline under some special environment and this sensor can carry out binary channels's sensing at same sensing area and can compensate its defect under special environment to a certain extent, and the utility model discloses a two resonance troughs that the sensor produced have obvious difference to make it can be more directly perceived bright when being utilized to observe, can play very profitable result in various detection areas because of its high sensitivity and convenient validity.

Drawings

FIG. 1 is based on TIO₂-a model diagram of a side edge polishing type dual-channel SPR sensor of an AU composite membrane and an ITO-AU composite membrane;

FIG. 2 is based on TIO₂-a longitudinal cross-sectional view of a side-polished dual-channel SPR sensor of an AU composite film and an ITO-AU composite film;

FIG. 3 is a test chart of the sensor system;

FIG. 4 is a SPR resonance spectrum of the sensor at a refractive index of 1.33;

FIG. 5 is a SPR resonance spectrum of the sensor at a refractive index of 1.39.

Detailed Description

The present invention will be further described with reference to the following embodiments.

As shown in fig. 1-3, the reference numbers are: TIO₂An AU composite film 1, a first gold film 2, a single-mode optical fiber core 3, a single-mode optical fiber cladding 4, a second gold film 5, an ITO-AU composite film 6, a broadband light source 7, a single-mode optical fiber jumper wire 8, a measurement area 9, a computer PC (personal computer) terminal 10, a spectrum analyzer 11, a sensing detector 12 and a single-mode optical fiber 13.

The broadband light source 7 enters the input end of the sensing detector 12 through a common single-mode optical fiber jumper wire 8 and is input into the measurement area 9, and then the TIO-based measurement is carried out₂The side edge polishing type double-channel SPR sensors of the-AU composite membrane 1 and the ITO-AU composite membrane 6 transmit detected optical signals to a spectrum analyzer 11 through output ends of the sensors through a single-mode optical fiber jumper wire 8, so that SPR is obtainedIn the vibration spectrum, the SPR resonance wavelength generates corresponding red shift and blue shift due to the change of the refractive index in the measurement area 9, and finally, a required resonance curve is obtained through the display of a computer PC terminal 10 and the parameter to be measured is obtained through analysis.

Examples

Based on TIO, as shown in FIG. 2₂Manufacturing the side edge polishing type double-channel SPR sensor of the AU composite film 1 and the ITO-AU composite film 6, wherein the manufacturing steps are as follows:

firstly, preparing a 9-125 mu m type single mode optical fiber 13, then removing a protective layer by using a wire stripper, then removing coating layers at positions, which need to be polished, on two sides of the single mode optical fiber 13 by using the wire stripper, exposing a bare fiber with the length of about 30mm, and fixing the bare fiber on a clamp of a platform after cleaning the bare fiber.

The height and tension of the polishing wheel are adjusted, the polishing parameters of the polishing machine are set at the upper end of the single-mode optical fiber 13, and the polishing is carried out to enable the residual cladding to be about 500nm away from the fiber core 3 of the single-mode optical fiber. And then, turning the position of the single-mode optical fiber 13, fixing the single-mode optical fiber on a platform clamp, setting polishing parameters, polishing the single-mode optical fiber to the position of the residual cladding, which is about 500nm away from the fiber core 3 of the single-mode optical fiber, finally, cleaning the polished single-mode optical fiber 13 by using deionized water, placing the single-mode optical fiber in a dryer for 10 minutes, drying the single-mode optical fiber, and fixing the single-mode optical fiber on a glass slide by using a copper foil adhesive tape.

Fixing the polished optical fiber fixed on the glass slide on a sample disc, vacuumizing a magnetron sputtering coating machine to 5pa, and vacuumizing a molecular pump to 8 multiplied by 10^-4pa, adjusting power until glow opens the baffle valve and sputter a first gold film 2 of about 50nm through the film thickness monitor and then close the baffle valve, and similarly sputter a 15nmTIO layer on the gold film plated on the upper side through the DC magnetron sputtering method₂Formation of TIO₂AU composite membrane 1.

The optical fiber with the composite film plated on the upper layer is turned over and fixed by the same direct current magnetron sputtering method, a second gold film 5 with the thickness of about 50nm is plated on the lower side, and an ITO film with the thickness of about 15nm is sputtered on the second gold film 5 to form an ITO-AU composite film 6. The fabricated sensor is packaged to protect its structure, forming a sensing probe 12.

This design simple structure, the sensing detector 12 who obtains through above-mentioned processing step connects according to the mode of fig. 3 and carries out the refractive index test, and concrete step is: firstly, a broadband light source is connected with the sensor through a single-mode optical fiber jumper 8 and a flange plate, so that the light source can enter the sensing detector 12. A glycerin solution having a refractive index of 1.33 to 1.39 was prepared as a measurement region 9 by an Abbe refractometer. The other end of the sensing probe 12 is connected to the optical spectrum analyzer 11 through a flange so that the optical signal can be output to the optical spectrum analyzer. The spectrum analyzer 11 is connected with the PC terminal 10 by the USB interface, and a dual-channel SPR resonance curve is obtained by receiving on a computer and is shown in figures 4 and 5.

As can be seen from FIGS. 4 to 5, in the refractive index of 1.33 to 1.39, the refractive index is represented by TIO₂The channel 1 generated by the composite membrane consisting of-AU can reach 3533nm/RIU, and the channel 2 of the composite membrane consisting of ITO-AU can reach 4138nm/RIU, so that double-channel sensing is realized.

Claims

1. A selectable dual channel fiber optic sensor, comprising: including single mode fiber core (3), set up single mode fiber cladding (4) at single mode fiber core (3) periphery single mode fiber cladding (4) upside and downside all set up the polish face region, set up TIO in the polish face region of upside₂An ITO-AU composite film (6) provided in the lower polished surface region of the AU composite film (1).

2. A selectable dual channel fiber optic sensor according to claim 1, wherein: in said TIO₂-AU composite membrane (1) comprising TIO₂A film layer and a first gold film (2); the ITO-AU composite film (6) comprises an ITO film layer and a second gold film (5).

3. A selectable dual channel fiber optic sensor according to claim 2, wherein: the TIO₂The thickness of the film layer is 15 nm; the thickness of the ITO film layer is 10 nm.

4. A selectable dual channel fiber optic sensor according to claim 2, wherein: the thickness of the first gold film (2) is 50 nm; the thickness of the second gold film (5) is 50 nm.

5. A selectable dual channel fiber optic sensor according to claim 2, wherein: the first gold film (2) is arranged on the TIO₂Between the film layer and the polishing surface area on the upper side; the second gold film (5) is arranged between the ITO film layer and the polishing surface area on the lower side.

6. A selectable dual channel fiber optic sensor according to claim 1, wherein: the length of the groove of the polishing and grinding surface area is 8 mm.

7. A selectable dual channel fiber optic sensor according to claim 1, wherein: and the distance between the single-mode fiber cladding (4) of the polished surface area and the single-mode fiber core (3) is 500 nm.