CN116519635A - Open C-type Fabry-Perot fiber seawater salinity sensor and manufacturing method thereof - Google Patents

Open C-type Fabry-Perot fiber seawater salinity sensor and manufacturing method thereof Download PDF

Info

Publication number
CN116519635A
CN116519635A CN202310518012.2A CN202310518012A CN116519635A CN 116519635 A CN116519635 A CN 116519635A CN 202310518012 A CN202310518012 A CN 202310518012A CN 116519635 A CN116519635 A CN 116519635A
Authority
CN
China
Prior art keywords
fiber
smf
optical fiber
hollow
type
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202310518012.2A
Other languages
Chinese (zh)
Inventor
刘睿杰
赵勇
吕日清
仝锐杰
林子婷
赵锦程
王煜
李超凡
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Northeastern University Qinhuangdao Branch
Original Assignee
Northeastern University Qinhuangdao Branch
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Northeastern University Qinhuangdao Branch filed Critical Northeastern University Qinhuangdao Branch
Priority to CN202310518012.2A priority Critical patent/CN116519635A/en
Publication of CN116519635A publication Critical patent/CN116519635A/en
Pending legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/25—Preparing the ends of light guides for coupling, e.g. cutting
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
    • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
    • G01D5/26—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light
    • G01D5/32—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light
    • G01D5/34—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells
    • G01D5/353—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre
    • G01D5/35306—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement
    • G01D5/35309—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer
    • G01D5/35312—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable characterised by optical transfer means, i.e. using infrared, visible, or ultraviolet light with attenuation or whole or partial obturation of beams of light the beams of light being detected by photocells influencing the transmission properties of an optical fibre using an interferometer arrangement using multiple waves interferometer using a Fabry Perot
    • 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
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • 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
    • G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
    • G01N21/45—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B6/00—Light guides; Structural details of arrangements comprising light guides and other optical elements, e.g. couplings
    • G02B6/24—Coupling light guides
    • G02B6/255—Splicing of light guides, e.g. by fusion or bonding
    • 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
    • G01N21/01—Arrangements or apparatus for facilitating the optical investigation
    • G01N2021/0106—General arrangement of respective parts
    • G01N2021/0112—Apparatus in one mechanical, optical or electronic block
    • 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
    • G01N21/41—Refractivity; Phase-affecting properties, e.g. optical path length
    • G01N21/45—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods
    • G01N2021/458—Refractivity; Phase-affecting properties, e.g. optical path length using interferometric methods; using Schlieren methods using interferential sensor, e.g. sensor fibre, possibly on optical waveguide
    • 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
    • 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 provides an open C-type Fabry-Perot fiber seawater salinity sensor and a manufacturing method thereof, and relates to the technical field of fiber sensing. The sensor structure of the invention is composed of a single-mode fiber and an hollow fiber/gold film, and the connection with a demodulator is realized through the single-mode fiber. And (3) side grinding the hollow optical fiber by an optical fiber grinder to enable the hollow optical fiber to be in a C-shaped structure, and plating gold films on the inner wall of the C-shaped open cavity and the two reflecting end surfaces of the inner wall of the C-shaped open cavity. In the invention, the sensing light beam is directly contacted with the detected substance, and the inner wall of the cavity of the hollow fiber C and the reflecting end face are coated with the gold film, so that the signal to noise ratio of the sensor signal demodulation is enhanced. The invention has advantages in the aspects of sensor structure, size and sensitivity of parameters to be measured, and provides a new scheme for measuring the salinity of the seawater.

Description

Open C-type Fabry-Perot fiber seawater salinity sensor and manufacturing method thereof
Technical Field
The invention relates to the technical field of optical fiber sensing, in particular to an open C-type Fabry-Perot optical fiber seawater salinity sensor and a manufacturing method thereof.
Background
Salinity is one of the important water parameters of seawater, and has profound effects on ocean natural activities such as ocean water movement, ocean race migration and the like. Salinity measurement plays an important role in a plurality of fields such as ocean monitoring, climate prediction, ecological protection and the like.
At present, the most used instruments of the equipment for measuring the salinity of the seawater are a thermal salt depth (CTD) measuring instrument, and the CTD measuring instrument has the advantages of high precision, pollution prevention of a conductivity probe and the like, but also has the problems that a sensing probe is expensive, electricity leakage is easy to occur in the seawater, long-term in-situ detection is difficult to realize and the like. In recent years, the optical fiber sensing technology has been rapidly developed, and compared with the traditional measurement technology, the optical fiber sensing technology has a plurality of irreplaceable advantages, such as compact structure, high sensitivity, high temperature resistance, corrosion resistance, high response speed, electromagnetic interference resistance, suitability for severe environments and the like. Optical fiber sensing technology is also proposed for salinity measurement, and the optical fiber salinity sensor can be divided into an FPI type, an MZI type, a microstructure optical fiber type and a Surface Plasmon Resonance (SPR) type according to a sensing principle, and according to researches, the salinity of seawater and the refractive index have a relation, and the outside liquid salinity is measured through the change of the refractive index of liquid.
In 2011, linh et al drilled square holes in the fiber core of a single-mode fiber by a focused ion beam processing technology, and led outside liquid to be measured into the square holes, and experimental results show that the salinity sensitivity of the sensor can reach 0.231nm/ppt. In 2019 Sun et al proposed a Fiber Bragg Grating (FBG) salinity sensor based on FBG parts coated with Polyimide (PI) for salinity sensing, although FBG sensors were simple in structure and suitable for long-term measurement, their sensitivity was very low, only-0.0358 nm/%. In 2020, wang et al proposed an optical fiber FPI sensor based on a surface waveguide, by using a femtosecond laser micromachining technology, two reflection surfaces are respectively introduced into a fiber core and a surface wave guide to form two FPIs, and the surface waveguide FPI is sensitive to an external refractive index, and the structure is firm and reliable, but the refractive index sensitivity is relatively low, which is only 843.3nm/RIU. In 2020, lin et al propose an optical fiber salinity sensor based on a single-mode optical fiber-coreless optical fiber-single-mode optical fiber (SSNSS) structure, which has high sensitivity in refractive index measurement, but has a problem of cycle crossing, which is inconvenient to realize subsequent demodulation processing. 2022, zhao et al proposed a novel fiber sensor based on FP and antiresonant structure cascade, constructed FP cavity and microchannel antiresonant structure in the sensing structure by using femtosecond laser micromachining technology and chemical corrosion, and used hollow fiber as microfluidic device to measure seawater salinity, the salinity sensitivity can reach-1.152 nm/mill, but the operation cost of the femtosecond laser micromachining technology is high. In summary, these sensors for measuring salinity have disadvantages in terms of measurement sensitivity, manufacturing difficulty, and the like.
Chinese patent CN115266582A proposes a Fabry-Perot (FP) resonant cavity type salinity sensor for in-situ measurement of sea water or liquid salinity parameters, but the structure has a plurality of required elements and the measurement steps are complex. The Chinese patent CN112781633A proposes a high-sensitivity sea water salt temperature dual-parameter sensor based on interference vernier effect, which realizes simultaneous measurement of sea water temperature and salinity, but adopts a discrete structure, an optical fiber coupler is needed, the whole is not compact, and distributed sensing is not easy to realize.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides an open C-type Fabry-Perot fiber seawater salinity sensor and a manufacturing method thereof.
In one aspect, an open type C-type Fabry-Perot fiber seawater salinity sensor comprises a single mode fiber, a hollow fiber and a gold film;
the single mode fiber comprises an input single mode fiber and an output single mode fiber, and the input single mode fiber, the hollow fiber and the output single mode fiber are sequentially welded, wherein two welding surfaces formed by the input single mode fiber and the hollow fiber and the output single mode fiber are set as M 1 And M 2 Fusion face M 1 And M 2 Two reflecting end faces as FP interferometers;
the hollow optical fiber is internally provided with a C-shaped open cavity, the C-shaped open cavity is manufactured by a side grinding micro-processing technology, and penetrates through the whole hollow optical fiber;
the gold film is coated on the inner wall of the C-shaped open cavity and the two reflecting end surfaces;
on the other hand, the manufacturing method of the open type C type Fabry-Perot optical fiber seawater salinity sensor is used for manufacturing the open type C type Fabry-Perot optical fiber seawater salinity sensor, and comprises the following steps of:
step 1: selecting an hollow optical fiber and a single-mode optical fiber, removing the two single-mode optical fibers and a coating layer on the end face of the hollow optical fiber, cutting off the uneven end face of the bare optical fiber by using an optical fiber cutting knife, and polishing;
step 2: welding SMF of a cut flat end surface with HCF of the cut flat end surface by using an arc welding machine; forming an SMF-HCF structure by using a fixed-length cutting system;
step 3: and welding the SMF-HCF structure with the SMF of the other cut flat end surface to form the composite double-cavity Fabry-Perot fiber salinity sensor with the SMF-HCF-SMF structure.
Step 4: placing the welded SMF-HCF-SMF structure in a clamp for accommodating the optical fibers, accommodating the clamp with the optical fiber structure in a grinder, adjusting the height of the clamp to enable the clamp to be in contact with sand paper, and resetting a dial indicator of the side bare fiber grinder;
step 5: starting a grinder, adjusting the height of the clamp, and observing the video microscope until the optical fiber contacts the grinding sand paper; the grinding is started after the hollow fiber is adjusted downwards to the set height, the set height is adjusted downwards again after the grinding is started to the set time, and the step is repeated until the hollow fiber is ground to be in a C-shaped structure;
step 6: and taking the side-polished SMF-HCF-SMF structure into a coating apparatus, and coating the inner wall of the C cavity and the two reflecting end surfaces with gold films with set thickness.
The beneficial effects of adopting above-mentioned technical scheme to produce lie in:
the invention provides an open C-type Fabry-Perot fiber seawater salinity sensor and a manufacturing method thereof; the invention provides an open type C-shaped structure seawater salinity sensor based on an optical fiber side grinding micro-processing technology, and the sensing structure has the advantages of high sensitivity, small structure size, simple connection and high-precision seawater salinity measurement potential.
Drawings
FIG. 1 is a schematic diagram of an optical fiber seawater salinity sensor based on an open C-type structure in an embodiment of the invention;
FIG. 2 is a schematic diagram of a method for measuring salinity by using an optical fiber seawater salinity sensor based on an open C-shaped structure in an embodiment of the invention;
FIG. 3 is a schematic diagram of a response curve of a Fabry-Perot FP structure of an optical fiber with a cavity length of 250 μm in an embodiment of the invention.
Detailed Description
The following describes in further detail the embodiments of the present invention with reference to the drawings and examples. The following examples are illustrative of the invention and are not intended to limit the scope of the invention.
An open type C-type Fabry-Perot fiber seawater salinity sensor, as shown in figure 1, comprises a single mode fiber, a hollow fiber and a gold film;
the single mode fiber comprises an input single mode fiber and an output single mode fiber, and the input single mode fiber, the hollow fiber and the output single mode fiber are sequentially welded, wherein two welding surfaces formed by the input single mode fiber and the hollow fiber and the output single mode fiber are set as M 1 And M 2 Fusion face M 1 And M 2 Two reflecting end faces as FP interferometers; from two reflecting end surfaces M 1 And M 2 The interference spectrum of FP can be obtained by the composed FP interferometer. By detecting the spectral shift caused by the salinity of the seawater, the measurement of the salinity of the seawater can be realized.
The hollow optical fiber is internally provided with a C-shaped open cavity, the C-shaped open cavity is manufactured by a side grinding micro-processing technology, and the C-shaped open cavity penetrates through the whole hollow optical fiber, so that the circulation of the cavity and an external tested substance is ensured;
the gold film is coated on the inner wall of the C-shaped open cavity and the two reflecting end faces, so that the input light emitted from the light source can be directly contacted with the external measured environment in the hollow optical fiber, meanwhile, the gold film can also enhance the signal-to-noise ratio of sensor signal demodulation, and the high-sensitivity measurement of the FP interferometer is ensured.
In this embodiment, the salinity measurement is performed by an optical fiber seawater salinity sensor and a demodulator, which are connected by a single-mode fiber, and a reflecting surface M 1 Is the interface of the welding part of the single-mode fiber and the C-type fiber, and the reflecting surface M 2 When the incident light reaches the reflecting surface M 1 At the time, part of beam I 1 Returning to leave a C-shaped semi-open cavity, penetrating the seawater to be measured to reach the reflecting surface M 2 Return beam I 2 Finally reaches the incident single-mode optical fiber to form an interference spectrum, but due to the reflecting surface M 1 And a reflecting surface M 2 In the case of immersing in seawater, since the refractive index difference between the optical fiber and the seawater is small, the reflectance thereof is greatly reduced, and it is difficult to obtain a good reflectance spectrum. Therefore, the invention is arranged on the reflecting surface M 1 And a reflecting surface M 2 A thin gold film is plated on the reflecting surface to enhance the reflectivity of the two reflecting surfaces; meanwhile, according to the formula (1), the variation sensitivity of the optical path difference OPD thereof increases as the cavity length increases, which is set to 1000 μm in order to improve the sensitivity of measurement. The C-shaped optical fiber to be used in the project is obtained by polishing and grinding an empty core optical fiber, and a semi-open cavity structure is constructed, so that seawater enters the cavity and is in direct contact with light. Meanwhile, in order to further reduce the loss caused by longer cavity, the inner wall of the half open hole is also plated with a gold film, so that the loss of signal light is reduced.
Where lambda is the wavelength of the incident light,is the phase difference between the two beams, L is the length of the interference area, and OPD is the optical path difference between the two beams.
On the other hand, the manufacturing method of the open type C type Fabry-Perot optical fiber seawater salinity sensor is used for manufacturing the open type C type Fabry-Perot optical fiber seawater salinity sensor, and comprises the following steps of:
step 1: using an air core optical fiber with an inner diameter of about 50 mu m and an outer diameter of about 150 mu m and a single mode optical fiber with an inner diameter of 125 mu m, removing coating layers on the two single mode optical fibers and the end faces of the air core optical fiber, cutting off the uneven end faces of the bare optical fiber by using an optical fiber cutting knife, and polishing to ensure that the end faces of the optical fiber are absolutely flat and strictly perpendicular to the optical fiber axis;
step 2: welding SMF of a cut flat end surface with HCF of the cut flat end surface by using an arc welding machine; cutting the hollow fiber with a length of about 900-1000 μm by using a fixed-length cutting system to form an SMF-HCF structure;
step 3: and welding the SMF-HCF structure with the SMF of the other cut flat end surface to form the composite double-cavity Fabry-Perot fiber salinity sensor with the SMF-HCF-SMF structure.
Step 4: placing the welded SMF-HCF-SMF structure in a clamp for accommodating optical fibers, selecting a grinding turntable with the diameter length of 5 mm, accommodating the clamp with the optical fiber structure in a grinder, adjusting the height of the clamp to be in contact with sand paper, and resetting a dial indicator of the side bare fiber grinder;
step 5: starting a grinder, adjusting the height of the clamp, and observing the video microscope until the optical fiber contacts the grinding sand paper; in this example, the polishing was started by adjusting 0.01mm downward, and the polishing was started for 1min, and again by adjusting 0.01mm downward, and this procedure was repeated until the hollow fiber was polished to have a C-shaped structure.
Step 6: and taking the side-polished SMF-HCF-SMF structure into a coating apparatus, and coating the inner wall of the C cavity and the two reflecting end surfaces with gold films with set thickness.
The method for measuring the salinity of the seawater by using the manufactured optical fiber sensor is shown in fig. 2, and specifically comprises the following steps: the demodulator scans and emits wide spectrum light, the single mode fiber made of quartz material enters the manufactured optical fiber sensing structure, the FPI interferometer is formed in the structure through reflection, the FPI interferometer is then transmitted to the demodulator through the output single mode fiber to form an FP interference spectrum signal, the interference spectrum signal is then transmitted to the upper computer to be subjected to band-pass filtering treatment, the center wavelength of a specific resonance peak corresponding to the spectrum and the spectrum of the salinity sensing cavity is obtained, the center wavelength movement amount of the specific resonance peak corresponding to the spectrum of the salinity sensing cavity in different salinity environments is calculated, and the salinity of sea water is reversely deduced.
Through analysis, the length of the sensing area is set to 1000 mu m, and the optical path difference variation sensitivity can reach 1000 mu m/RIU theoretically. In the aspect of experiments, an optical fiber FP structure with the cavity length of 250 mu m is prepared, the refractive index sensing characteristic and a coating process are analyzed initially, as shown in fig. 3, the refractive index sensitivity of about 247 mu m/RIU is obtained, meanwhile, the salinity sensitivity is obtained by conversion and reaches 50 nm/mill, when the cavity length is set to 1000 mu m, higher resolution is expected to be realized, and the measurement requirement of the invention is met. Higher sensitivity can be obtained when the FP cavity length is increased.
The foregoing description is only of the preferred embodiments of the present disclosure and description of the principles of the technology being employed. It will be appreciated by those skilled in the art that the scope of the invention in the embodiments of the present disclosure is not limited to the specific combination of the above technical features, but encompasses other technical features formed by any combination of the above technical features or their equivalents without departing from the spirit of the invention. Such as the above-described features, are mutually substituted with (but not limited to) the features having similar functions disclosed in the embodiments of the present disclosure.

Claims (3)

1. An open type C-type Fabry-Perot fiber seawater salinity sensor is characterized by comprising a single-mode fiber, a hollow fiber and a gold film;
the single mode fiber comprises an input single mode fiber and an output single mode fiber, and the input single mode fiber, the hollow fiber and the output single mode fiber are sequentially welded, wherein two welding surfaces formed by the input single mode fiber and the hollow fiber and the output single mode fiber are set as M 1 And M 2 Fusion face M 1 And M 2 Two reflecting end faces as FP interferometers;
the gold film is coated on the inner wall of the C-shaped open cavity and the two reflecting end surfaces.
2. An open C-type fabry-perot fiber seawater salinity sensor according to claim 1, wherein a C-type open cavity is provided in the hollow fiber, the C-type open cavity being made by a side grinding micro-machining technique, throughout the hollow fiber.
3. An open type C-type fabry-perot fiber seawater salinity sensor manufacturing method for manufacturing the open type C-type fabry-perot fiber seawater salinity sensor according to claim 1, comprising the following steps:
step 1: selecting an hollow optical fiber and a single-mode optical fiber, removing the two single-mode optical fibers and a coating layer on the end face of the hollow optical fiber, cutting off the uneven end face of the bare optical fiber by using an optical fiber cutting knife, and polishing;
step 2: welding SMF of a cut flat end surface with HCF of the cut flat end surface by using an arc welding machine; forming an SMF-HCF structure by using a fixed-length cutting system;
step 3: welding the SMF-HCF structure with another SMF with a cut flat end surface to form a composite double-cavity Fabry-Perot fiber salinity sensor with the SMF-HCF-SMF structure;
step 4: placing the welded SMF-HCF-SMF structure in a clamp for accommodating the optical fibers, accommodating the clamp with the optical fiber structure in a grinder, adjusting the height of the clamp to enable the clamp to be in contact with sand paper, and resetting a dial indicator of the side bare fiber grinder;
step 5: starting a grinder, adjusting the height of the clamp, and observing the video microscope until the optical fiber contacts the grinding sand paper; the grinding is started after the hollow fiber is adjusted downwards to the set height, the set height is adjusted downwards again after the grinding is started to the set time, and the step is repeated until the hollow fiber is ground to be in a C-shaped structure;
step 6: and taking the side-polished SMF-HCF-SMF structure into a coating apparatus, and coating the inner wall of the C cavity and the two reflecting end surfaces with gold films with set thickness.
CN202310518012.2A 2023-05-10 2023-05-10 Open C-type Fabry-Perot fiber seawater salinity sensor and manufacturing method thereof Pending CN116519635A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310518012.2A CN116519635A (en) 2023-05-10 2023-05-10 Open C-type Fabry-Perot fiber seawater salinity sensor and manufacturing method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310518012.2A CN116519635A (en) 2023-05-10 2023-05-10 Open C-type Fabry-Perot fiber seawater salinity sensor and manufacturing method thereof

Publications (1)

Publication Number Publication Date
CN116519635A true CN116519635A (en) 2023-08-01

Family

ID=87400839

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310518012.2A Pending CN116519635A (en) 2023-05-10 2023-05-10 Open C-type Fabry-Perot fiber seawater salinity sensor and manufacturing method thereof

Country Status (1)

Country Link
CN (1) CN116519635A (en)

Similar Documents

Publication Publication Date Title
Qian et al. Review of salinity measurement technology based on optical fiber sensor
US9285534B2 (en) Fiber-optic surface plasmon resonance sensor and sensing method using the same
CN106596474B (en) Three-channel SPR sensor based on seven-core optical fiber
CN103868457B (en) Optical fiber multiple spot micro-displacement sensing method and device based on surface plasma resonance
WO2005038423A1 (en) Tapered fiber optic strain gauge using cavity ring-down spectroscopy
CN102095719A (en) Optical fiber type sensor system based on surface plasma resonance and stimulated Raman scattering
Qiu et al. Plasmonic fiber-optic refractometers based on a high Q-factor amplitude interrogation
CN116559117A (en) Probe type optical fiber seawater salinity sensor based on FP interference and manufacturing method thereof
CN109655176B (en) High-precision temperature probe based on cavity filling type microstructure optical fiber interferometer
CN113295193B (en) Manufacturing method of single optical fiber cascading type temperature-depth-salinity sensor for deep sea surveying
CN103900992B (en) Interior outstanding core fibre grating temperature auto-compensation microfluidic sensor and interior outstanding core fibre
Yin et al. Experimental study of surface plasmon resonance refractive index sensor based on side-polished few-mode fiber
CN112710633A (en) Method for preparing splicing structure Mach-Zehnder refractive index sensor
Cennamo et al. Bio and chemical sensors based on surface plasmon resonance in a plastic optical fiber
CN116519635A (en) Open C-type Fabry-Perot fiber seawater salinity sensor and manufacturing method thereof
CN110823808A (en) Tapered side-polished optical fiber biosensor and method for preparing tapered side-polished optical fiber
CN111928880B (en) Mach-Zehnder interference optical fiber based on surface plasma effect and sensor thereof
CN113702339B (en) Parallel SPR sensor based on capillary optical fiber
Liyun et al. Optical fiber sensor determination of the water salinity based on surface plasmon resonance
Bekmurzayeva et al. Fabrication and interrogation of refractive index biosensors based on etched fiber Bragg grating (EFBG)
CN113959988A (en) Tandem SPR sensor based on capillary optical fiber
CN114061801A (en) Optical fiber V-groove cladding SPR strain sensor and manufacturing method thereof
CN113049181A (en) Method for manufacturing optical fiber Fabry-Perot vacuum gauge
Villatoro et al. Simplification of data extraction and measurements from tilted FBG surface plasmon resonance sensors
Deng et al. Miniaturized fiber-optic Fabry-Perot interferometer for highly sensitive refractive index measurement

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination