CN111307742A - Preparation method of enhanced guided-mode resonance optical fiber sensor - Google Patents
Preparation method of enhanced guided-mode resonance optical fiber sensor Download PDFInfo
- Publication number
- CN111307742A CN111307742A CN202010211865.8A CN202010211865A CN111307742A CN 111307742 A CN111307742 A CN 111307742A CN 202010211865 A CN202010211865 A CN 202010211865A CN 111307742 A CN111307742 A CN 111307742A
- Authority
- CN
- China
- Prior art keywords
- optical fiber
- grating
- groove
- layer
- mode
- 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.)
- Granted
Links
- 239000013307 optical fiber Substances 0.000 title claims abstract description 93
- 238000002360 preparation method Methods 0.000 title claims abstract description 10
- 238000000034 method Methods 0.000 claims abstract description 37
- 238000005530 etching Methods 0.000 claims abstract description 18
- 238000005520 cutting process Methods 0.000 claims abstract description 11
- 238000010884 ion-beam technique Methods 0.000 claims abstract description 9
- 238000005498 polishing Methods 0.000 claims abstract description 6
- 238000005229 chemical vapour deposition Methods 0.000 claims abstract description 4
- 229910000510 noble metal Inorganic materials 0.000 claims abstract description 4
- 238000000151 deposition Methods 0.000 claims abstract description 3
- 238000001259 photo etching Methods 0.000 claims abstract description 3
- 238000004544 sputter deposition Methods 0.000 claims abstract description 3
- 239000000835 fiber Substances 0.000 claims description 23
- 230000010287 polarization Effects 0.000 claims description 14
- 239000010408 film Substances 0.000 claims description 10
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 5
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 claims description 5
- 229910052737 gold Inorganic materials 0.000 claims description 5
- 239000010931 gold Substances 0.000 claims description 5
- 229910052709 silver Inorganic materials 0.000 claims description 5
- 239000004332 silver Substances 0.000 claims description 5
- 238000005253 cladding Methods 0.000 claims description 4
- 230000005684 electric field Effects 0.000 claims description 4
- 229910003460 diamond Inorganic materials 0.000 claims description 3
- 239000010432 diamond Substances 0.000 claims description 3
- 238000004088 simulation Methods 0.000 claims description 3
- 239000010409 thin film Substances 0.000 claims description 3
- 238000004364 calculation method Methods 0.000 claims description 2
- 230000000694 effects Effects 0.000 description 8
- 238000001514 detection method Methods 0.000 description 6
- 239000000523 sample Substances 0.000 description 6
- 238000001228 spectrum Methods 0.000 description 6
- 230000008569 process Effects 0.000 description 5
- 230000035945 sensitivity Effects 0.000 description 5
- 229910052581 Si3N4 Inorganic materials 0.000 description 4
- 238000010276 construction Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000003287 optical effect Effects 0.000 description 4
- 238000000985 reflectance spectrum Methods 0.000 description 4
- 230000009471 action Effects 0.000 description 3
- 238000003745 diagnosis Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000000206 photolithography Methods 0.000 description 3
- PBCFLUZVCVVTBY-UHFFFAOYSA-N tantalum pentoxide Inorganic materials O=[Ta](=O)O[Ta](=O)=O PBCFLUZVCVVTBY-UHFFFAOYSA-N 0.000 description 3
- 230000005540 biological transmission Effects 0.000 description 2
- 210000004204 blood vessel Anatomy 0.000 description 2
- 238000001755 magnetron sputter deposition Methods 0.000 description 2
- 238000005507 spraying Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000000758 substrate Substances 0.000 description 2
- JHKXZYLNVJRAAJ-WDSKDSINSA-N Met-Ala Chemical compound CSCC[C@H](N)C(=O)N[C@@H](C)C(O)=O JHKXZYLNVJRAAJ-WDSKDSINSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 238000007526 fusion splicing Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 239000011159 matrix material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 238000000691 measurement method Methods 0.000 description 1
- 230000000149 penetrating effect Effects 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000005855 radiation Effects 0.000 description 1
- 238000002310 reflectometry Methods 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 238000002198 surface plasmon resonance spectroscopy Methods 0.000 description 1
- 238000000411 transmission spectrum Methods 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
Images
Classifications
-
- 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
- G01N21/25—Colour; Spectral properties, i.e. comparison of effect of material on the light at two or more different wavelengths or wavelength bands
- G01N21/31—Investigating relative effect of material at wavelengths characteristic of specific elements or molecules, e.g. atomic absorption spectrometry
-
- 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
- G01D5/268—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 using optical fibres
-
- 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
- G02B6/02—Optical fibres with cladding with or without a coating
- G02B6/02057—Optical fibres with cladding with or without a coating comprising gratings
- G02B6/02076—Refractive index modulation gratings, e.g. Bragg gratings
- G02B6/02123—Refractive index modulation gratings, e.g. Bragg gratings characterised by the method of manufacture of the grating
Abstract
The invention discloses a preparation method of an enhanced guided mode resonance optical fiber sensor, which comprises the following steps: a, cutting an end face which is vertical to the axial direction of an optical fiber by 90 degrees on a single mode optical fiber, and polishing the end face; b, growing a layer of uniform film with high refractive index on the end surface by using a sputtering or chemical vapor deposition method to serve as a waveguide layer; step C, preparing a grating structure on the surface of the waveguide layer by utilizing a photoetching and etching method; the area size of the grating structure is not less than 20 x 20 microns; step D, etching a groove at two opposite positions of the grating area by using a focused ion beam system; and E, depositing a layer of noble metal film with the thickness of about 300nm on the inner side walls of the two grooves by using a focused ion beam system. The scheme can effectively improve the resonance signal of the optical fiber RWG structure and improve the signal-to-noise ratio, thereby meeting the practical requirement.
Description
Technical Field
The invention belongs to the field of optical sensing, and particularly relates to a preparation method of an enhanced guided mode resonance optical fiber sensor.
Background
The optical fiber sensor has the advantages of compact structure, high sensitivity, realization of remote sensing and the like, and has wide application in the fields of biochemical detection, gas detection, temperature sensing and the like. According to the working principle, the optical fiber sensor is mainly classified into an evanescent field action type (including an interference type, a bragg grating type, etc.) optical fiber sensor, a fabry-perot resonator type optical fiber sensor (hereinafter referred to as an F-P type), a surface plasmon resonance type optical fiber sensor (hereinafter referred to as an SPR type), and the like. In order to extract evanescent waves, an evanescent field action type optical fiber sensor needs to remove an optical fiber cladding, or adopts methods such as tapering, fusion splicing of different types of optical fibers and the like to excite a cladding mode, the methods can cause great damage to the mechanical properties of the optical fibers, the optical fibers are easy to deform or break, so that the working stability of the sensor is influenced, the sensing action area is usually longer (several centimeters), and a large amount of samples to be detected are needed; the detection range of the F-P type optical fiber sensor is inversely proportional to the sensing sensitivity, so that the further improvement of the performance of the F-P type optical fiber sensor is limited; the SPR type sensor usually requires complicated processes such as tapering and tapering, or uses an expensive multi-core optical fiber, and its resonance wavelength is usually in the visible light band rather than the common optical fiber communication band, and the line width of the absorption peak is also wide, thereby having adverse effects on the sensing performance.
Guided mode Resonance (RWG) is a resonance phenomenon based on Waveguide gratings. When a plane wave is incident to a waveguide surface with a sub-wavelength grating engraved on the surface, if the first-order scattering of the plane wave and a certain waveguide mode just meet a phase matching condition, the scattering signal is converted into the waveguide mode and continues to radiate outwards through the grating, and the radiation signal and a zero-order transmission signal of the plane wave have opposite phases, so that the total transmission signal is zero, and energy is totally reflected back. This resonance phenomenon occurs only at specific wavelengths and incident angles, and therefore, if the incident light is a wide-spectrum light source, the reflection signal is measured, and a resonance peak with a reflectivity of one hundred percent can be obtained on the spectrogram. When the refractive index is changed due to the change of the external environment or the structural parameters such as the thickness of the grating are changed, the resonance peak is shifted, so that the sensing function can be realized.
At present, RWG structures have implemented filtering, sensing, etc. functions on planar substrates of glass, crystal, or polymer, etc. If the structure can be introduced on an optical fiber, a fiber sensing function can be achieved. Compared with the traditional optical fiber sensor, the optical fiber sensor based on the RWG effect has the following advantages: (1) the sensing area is small (the size is only about twenty microns), and the method is suitable for detecting trace substances; (2) the optical fiber sensor has the advantages that processes such as tapering, welding and the like are not needed, good mechanical properties of the optical fiber can be kept, the overall structure of the sensor is compact, and the optical fiber sensor is very suitable for being penetrated into blood vessels or tissues of a human body to carry out real-time medical diagnosis; (3) meanwhile, the high sensing sensitivity and the wide detection range are realized; (4) the device is not easily disturbed by other factors such as temperature and the like, and the result is stable and reliable; (5) the optical fiber is very easy to combine with a multi-core optical fiber, and the simultaneous detection of different substance components or multiple physical quantities is realized.
However, it is still difficult to achieve an effective RWG effect in fiber structures today, with the main difficulties: the electromagnetic wave transmitted in the optical fiber has a small mode size (about 10 microns), so that only a small portion of the grating scattered signal can be coupled back to the optical fiber mode, which can be simply understood as: only the grating period in a small region near the core contributes to the RWG effect, which is the greatest difference from planar RWG devices. As a result, in the optical fiber RWG structure, the resonance peak of the reflected signal is weak, and the signal-to-noise ratio is low, so that the application demand cannot be met.
For example: D. wawro et al have reported that an ultraviolet laser interference method is used for preparing an RWG structure on an optical fiber head, but the intensity of a resonance peak in a reflection spectrum is only 18 percent, and the signal-to-noise ratio is low, so that the practical requirement is difficult to achieve; in 2018, H, Hemmati et al report that RWG sensors are prepared on optical fiber heads, the formant intensity of the RWG sensors reaches about 40%, but the adopted method is that multimode optical fibers with the diameter of more than 200 microns are welded at the rear ends of single-mode optical fibers, and signals of the multimode optical fibers are difficult to return to the single-mode optical fibers, so that the RWG sensors can only work in a mode of measuring transmission spectrums. In many practical applications, such as remote sensing, real-time medical diagnosis, etc., the optical fiber sensor must work by using a reflection spectrum measurement method.
Disclosure of Invention
In order to overcome the defects, the invention provides a preparation scheme of an F-P cavity enhanced optical fiber RWG sensor. The scheme can effectively improve the resonance signal of the optical fiber RWG structure and improve the signal-to-noise ratio, thereby meeting the practical requirement.
The technical scheme adopted by the application is as follows:
a preparation method of an optical fiber sensor comprises the following steps: the method comprises the following steps:
a, manufacturing a plane which is perpendicular to an optical fiber and has better flatness on a polarization-maintaining single-mode optical fiber (or a common single-mode optical fiber with a polarization controller) by utilizing a cutting and polishing method, or directly cutting a plane with good optical quality by utilizing a precision diamond knife cutting method;
b, growing a layer of uniform film with high refractive index on the plane by sputtering or chemical vapor deposition and the like to be used as a waveguide layer;
and step C, preparing a grating structure on the surface of the waveguide layer by utilizing the photoetching and etching technology. The grating structure is sized to cover only a small area, typically around 20 microns by 20 microns, near the core region of the fiber. Note that if a polarization maintaining fiber is used, the prepared grating direction requirement is: the grating grooves run parallel to one of the principal axes (fast or slow) of the polarization maintaining fiber and require the polarization direction of the electric field of the incident light to be parallel to the principal axis. This step can also be replaced by a method such as focused ion beam etching, and the focused ion beam is abbreviated as FIB hereinafter.
In step B, C, the specific parameters of the waveguide layer and the grating, such as the thickness, the grating period, and the duty ratio, may be designed and optimized by using a theory or simulation method, such as a thin film optical transfer matrix theory and a rigorous coupled wave analysis method.
Step D, etching two grooves at two opposite positions of the grating area by using an FIB system, wherein the position requirements of the right groove are as follows: the inner side wall of the groove is positioned in the center of the Nth grating protrusion on the right side of the central axis of the optical fiber (assuming that the central axis of the optical fiber corresponds to the etched part of the grating); the position of the left side groove is symmetrical to that of the right side groove; the optimum value of N is determined by theoretical or simulation calculations, typically 8-11; the depth of the trench is about 1-2 microns and the width is about several microns (there is no strict requirement on the size of the trench).
And step E, growing a layer of gold film or silver film with the thickness of about 300nm on the inner side walls of the two grooves by using an FIB system.
A second part: the specific implementation method of the optical fiber sensing comprises the following steps:
a wide-spectrum light source (such as a super-luminescent diode (SLD)) is used as an excitation light source, and a signal passes through an optical isolator and then is connected into an optical fiber circulator and then is connected into an optical fiber sensing probe. The reflected signal passes through the circulator again and is received by the spectrometer, and the sensing function can be realized by reading the data of the spectrometer. In the system, the optical fibers all use single-mode polarization-maintaining optical fibers or common single-mode optical fibers with polarization controllers.
The invention has the beneficial effects that:
1. compared with an optical fiber RWG sensor which is not enhanced by an F-P cavity, the resonance peak value can be obviously enhanced, and the signal to noise ratio is improved, so that the practical requirement of the optical fiber sensor is met;
2. the structure is compact, the mechanical performance is good, the remote sensing can be realized through the measurement of the reflected signal, and the device is particularly suitable for penetrating into blood vessels and tissues of a human body along with an injector or a probe to perform real-time medical diagnosis;
3. can simultaneously realize higher sensing precision and wider detection range, and is suitable for detecting trace samples to be detected.
Drawings
FIG. 1 is a schematic view; fiber optic sensor schematic (side view);
FIG. 2 is a schematic view; fiber optic sensor schematic (top view);
FIG. 3 is a schematic view; an integral construction method (schematic diagram) of the optical fiber sensing system;
FIG. 4 is a schematic view; the reflectance spectrum of example 1 (solid line, ambient refractive index 1.33); the reflection spectrum (dotted line) of the optical fiber sensor with the same structural parameters but without a reflector and a groove is used as comparison;
FIG. 5 is a schematic view; the reflectance spectrum of example 1 varied with the ambient refractive index. The solid line and the dotted line correspond to the ambient refractive index of 1.33 and 1.35 respectively;
FIG. 6 is a schematic view; the reflectance spectrum of example 3 (solid line, ambient refractive index 1.33); the reflection spectrum (dotted line) of the optical fiber sensor with the same structural parameters but without a reflector and a groove is used as comparison;
FIG. 7 is a schematic view; the reflectance spectrum of example 3 varied with the ambient refractive index. The solid and dashed lines correspond to ambient refractive indices 1.33, 1.38, respectively;
wherein, 1: a fiber core; 2: a fiber cladding; 3: a waveguide layer; 4: a grating; 5: noble metal thin films (mirrors); 6: a trench; 7: a polarization controller; 8: a broad spectrum light source; 9: a spectrometer; 10: a fiber optic circulator; 11: an optical fiber sensor probe.
Detailed Description
It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the disclosure. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.
Embodiment 1 a method for manufacturing an enhanced guided-mode resonance fiber sensor, comprising the steps of:
and step A, cutting an end face which is vertical to the axial direction of the optical fiber by 90 degrees on the common single-mode optical fiber, and polishing the end face.
Step B, utilizing magnetron sputtering to make said end surface be covered with a layer of metalA layer of Si with the thickness of 350nm is grown on the silicon substrate3N4Layer, method using photolithography combined with reactive ion beam etching, on Si3N4The grating structure with equal periods is etched on the layer, the size of the grating area is 25 multiplied by 25 mu m, the etching depth is 200nm, the grating period is 1030nm, and the duty ratio is 77 percent (namely Si)3N4Fraction 77%). The etched structure is made of Si with the thickness of 150nm3N4Layer uniformity and 200nm thick Si3N4Layer grating.
And step C, etching two opposite grooves at specific positions of the grating by using an FIB system, wherein the width of each groove is about 2 μm (the width is not specifically required), and the depth of each groove is about 1.5 μm. The position requirements of the right side groove are as follows: the inner side wall of the groove is positioned at the 9 th Si on the right side of the central axis of the optical fiber3N4The center of the layer grating protrusion (assuming that the central axis of the fiber corresponds to the etched portion of the grating). The left side groove is symmetrical with the right side groove in position. Here, it should be noted that: in the actual process, the grating is not necessarily ensured to be symmetrical relative to the central axis of the optical fiber, so that only about the 9 th Si on the two sides of the central axis of the optical fiber on the inner side of the groove is required3N4The center of the grating protrusion is sufficient, but it is required that the inner side of the groove must be located near the center of a certain grating protrusion.
And D, depositing a layer of gold or silver film serving as a reflecting mirror with the thickness of about 300nm on the inner sides of the two grooves by using an FIB system. The two mirrors form an F-P cavity. The steps A to D are the preparation method of the optical fiber sensing probe.
The construction method of the optical fiber sensing system and the specific implementation method of sensing are the same as the implementation method of optical fiber sensing in the foregoing, and the effect of this embodiment is shown in fig. 4 and 5. Therefore, compared with the conventional optical fiber RWG sensor without using F-P cavity enhancement, the invention can obviously enhance the resonance effect and improve the signal-to-noise ratio of the sensor. The sensitivity of the sensor was approximately 180 nm/RIU.
a, cutting an end face which is perpendicular to the axial direction of the optical fiber at 90 degrees by using a precision diamond cutter cutting technology on the polarization-preserving single-mode optical fiber, wherein the end face obtained by cutting by the technology has extremely low roughness and does not need further grinding and polishing;
step B, growing a layer of Si with the thickness of 350nm on the end face by utilizing magnetron sputtering3N4Layer, method using photolithography combined with reactive ion beam etching, on Si3N4Etching the grating structure with equal period on the layer, wherein the etching depth is 200nm, the grating period is 1030nm, and the duty ratio is 77% (namely Si)3N4Fraction 77%). The etched structure is made of Si with the thickness of 150nm3N4Layer uniformity and 200nm thick Si3N4Layer grating. The requirements for the grating direction are: the grating grooves run parallel to one of the principal axes (fast or slow) of the polarization maintaining fiber and require the polarization direction of the electric field of the incident light to be parallel to the principal axis.
And step C, etching two opposite grooves at specific positions of the grating by using an FIB system, wherein the width of each groove is about 2 μm (the width is not specifically required), and the depth of each groove is about 1.5 μm. The position requirements of the right side groove are as follows: the inner side wall of the groove is positioned at the 9 th Si on the right side of the central axis of the optical fiber3N4The center of the layer grating protrusion (assuming that the central axis of the fiber corresponds to the etched portion of the grating). The left side groove is symmetrical with the right side groove in position. Here, it should be noted that: in the actual process, the grating is not necessarily ensured to be symmetrical relative to the central axis of the optical fiber, so that only about the 9 th Si on the two sides of the central axis of the optical fiber on the inner side of the groove is required3N4The center of the grating protrusion is sufficient, but it is required that the inner side of the groove must be located near the center of a certain grating protrusion.
And D, spraying a layer of gold or silver film serving as a reflecting mirror with the thickness of about 300nm on the inner sides of the two grooves by using an FIB system. The steps 1-4 are the preparation method of the optical fiber sensing probe.
The construction method of the optical fiber sensing system and the specific implementation method of sensing are the same as the implementation method of optical fiber sensing in the foregoing.
Embodiment 3 a method for manufacturing an enhanced guided-mode resonance fiber sensor, comprising the steps of:
and step A, cutting an end face which is vertical to the axial direction of the optical fiber by 90 degrees on the common single-mode optical fiber, and polishing the end face.
Step B, growing a layer of Ta with the thickness of 370nm on the end face by using a chemical vapor deposition method2O5And (3) a layer. Using photolithography in combination with reactive ion beam etching, at Ta2O5And etching the layer with periodic grating structure. This step can also be prepared by FIB or the like. The etching depth is 180nm, the grating period is 940nm, and the duty ratio is 60 percent (namely Ta)2O5The portion accounts for 60%). The etched structure consists of 190nm thick Ta2O5The uniform layer was composed of a 180nm thick Ta2O5 grating. Note that if a polarization maintaining fiber is used, it is required that the grating grooves run parallel to one principal axis direction (fast axis or slow axis) of the polarization maintaining fiber, and that the electric field polarization direction of the incident light is parallel to the principal axis. .
And step C, etching two opposite grooves at specific positions of the grating by using an FIB system, wherein the width of each groove is about 2 μm (the width is not specifically required), and the depth of each groove is about 1.4 μm. The position requirements of the right side groove are as follows: the inner side wall of the groove is positioned at the 8 th Ta on the right side of the central axis of the optical fiber2O5The center of the grating protrusion (assuming that the central axis of the fiber corresponds to the etched portion of the grating). The left side groove is symmetrical with the right side groove in position. Here, it should be noted that: in the actual process, the grating is not necessarily ensured to be symmetrical relative to the central axis of the optical fiber, so that only about the 8 th Ta on the inner side of the groove, which is positioned on two sides of the central axis of the optical fiber, is required2O5The center of the grating protrusion is sufficient, but it is required that the inner side of the groove must be located near the center of a certain grating protrusion.
And D, spraying a layer of gold or silver film serving as a reflecting mirror with the thickness of about 300nm on the inner sides of the two grooves by using an FIB system. The steps 1-4 are the preparation method of the optical fiber sensing probe.
The construction method of the optical fiber sensing system and the specific implementation method of sensing are the same as the implementation method of optical fiber sensing in the foregoing.
Further description of this example: the effect of this embodiment is shown in fig. 6 and 7. Therefore, compared with the conventional optical fiber RWG sensor without using F-P cavity enhancement, the invention can obviously enhance the resonance effect and improve the signal-to-noise ratio of the sensor. The sensitivity of the sensor is approximately 140 nm/RIU.
It will be evident to those skilled in the art that the invention is not limited to the details of the foregoing illustrative embodiments, and that the present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof. The present embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. Any reference sign in a claim should not be construed as limiting the claim concerned.
Claims (6)
1. A preparation method of an enhanced guided-mode resonance optical fiber sensor is characterized by comprising the following steps:
a, cutting an end face which is vertical to the axial direction of an optical fiber by 90 degrees on a single mode optical fiber, and polishing the end face;
b, growing a layer of uniform film with high refractive index on the end surface by using a sputtering or chemical vapor deposition method to serve as a waveguide layer;
step C, preparing a grating structure on the surface of the waveguide layer by utilizing a photoetching and etching method; the area size of the grating structure is not less than 20 x 20 microns;
step D, etching a groove at two opposite positions of the grating area by using a focused ion beam system, wherein the position requirements of the groove at the right side are as follows: the inner side wall of the groove is positioned in the center of the Nth grating protrusion on the right side of the central axis of the optical fiber (assuming that the central axis of the optical fiber corresponds to the etched part of the grating); the position of the left side groove is symmetrical to that of the right side groove; the optimum value of N is determined by theoretical or simulation calculations, typically 8-11;
and E, depositing a layer of noble metal film with the thickness of about 300nm on the inner side walls of the two grooves by using a focused ion beam system.
2. The method according to claim 1, wherein the single-mode fiber is a polarization-maintaining single-mode fiber or a normal single-mode fiber with a polarization controller.
3. The method according to claim 1, wherein the end surface of step a is obtained by direct cutting with a precision diamond knife.
4. The method according to claim 2, wherein in step C, when the optical fiber is a polarization maintaining single mode optical fiber, the grating direction requirement is: the grating grooves run parallel to one main axis direction (fast axis or slow axis) of the polarization-maintaining single-mode fiber, and require the electric field polarization direction of incident light to be parallel to the main axis.
5. The method according to claim 1, wherein the noble metal thin film in step E is a gold film or a silver film.
6. The method as claimed in claim 1, wherein the trench is deeper into the optical fiber cladding by a depth greater than 500nm in step D.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010211865.8A CN111307742B (en) | 2020-03-24 | 2020-03-24 | Preparation method of enhanced guided-mode resonance optical fiber sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202010211865.8A CN111307742B (en) | 2020-03-24 | 2020-03-24 | Preparation method of enhanced guided-mode resonance optical fiber sensor |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN111307742A true CN111307742A (en) | 2020-06-19 |
| CN111307742B CN111307742B (en) | 2023-01-17 |
Family
ID=71149781
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202010211865.8A Active CN111307742B (en) | 2020-03-24 | 2020-03-24 | Preparation method of enhanced guided-mode resonance optical fiber sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN111307742B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6259847B1 (en) * | 1999-04-07 | 2001-07-10 | Lucent Technologies Inc. | Optical communication system including broadband all-pass filter for dispersion compensation |
| CN101021596A (en) * | 2007-03-09 | 2007-08-22 | 重庆工学院 | Optical fiber Bragg grating sensor and method for on-line measuring microbial film thickness thereof |
| US20120229793A1 (en) * | 2011-03-11 | 2012-09-13 | University of Maribor | Optical fiber sensors having long active lengths, systems, and methods |
| CN105403535A (en) * | 2015-10-22 | 2016-03-16 | 重庆理工大学 | Fiber cladding surface Bragg grating biochemical sensor and making method thereof |
| CN109001157A (en) * | 2018-06-22 | 2018-12-14 | 江南大学 | A method of refractive index sensing is realized based on duplex surface plasma resonance |
-
2020
- 2020-03-24 CN CN202010211865.8A patent/CN111307742B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6259847B1 (en) * | 1999-04-07 | 2001-07-10 | Lucent Technologies Inc. | Optical communication system including broadband all-pass filter for dispersion compensation |
| CN101021596A (en) * | 2007-03-09 | 2007-08-22 | 重庆工学院 | Optical fiber Bragg grating sensor and method for on-line measuring microbial film thickness thereof |
| US20120229793A1 (en) * | 2011-03-11 | 2012-09-13 | University of Maribor | Optical fiber sensors having long active lengths, systems, and methods |
| CN105403535A (en) * | 2015-10-22 | 2016-03-16 | 重庆理工大学 | Fiber cladding surface Bragg grating biochemical sensor and making method thereof |
| CN109001157A (en) * | 2018-06-22 | 2018-12-14 | 江南大学 | A method of refractive index sensing is realized based on duplex surface plasma resonance |
Non-Patent Citations (2)
| Title |
|---|
| LINYONG QIAN,ET AL: "Enhanced sensing ability in a single-layer guided-mode resonant optical biosensor with deep grating", 《OPTICS COMMUNICATIONS》 * |
| 卢希: "基于双面亚波长光栅的高灵敏度折射率传感器", 《中国优秀硕士学位论文全文数据库 信息科技辑》 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN111307742B (en) | 2023-01-17 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ding et al. | Surface plasmon resonance refractive index sensor based on tapered coreless optical fiber structure | |
| CN108027313B (en) | Resonant periodic structures and methods of using them as filters and sensors | |
| Schuster et al. | Miniaturized long-period fiber grating assisted surface plasmon resonance sensor | |
| US9285534B2 (en) | Fiber-optic surface plasmon resonance sensor and sensing method using the same | |
| Chen et al. | Review of femtosecond laser machining technologies for optical fiber microstructures fabrication | |
| Hu et al. | High sensitivity fiber optic SPR refractive index sensor based on multimode-no-core-multimode structure | |
| CN108844919B (en) | Cladding reflection type inclined fiber grating refractive index sensor and manufacturing and measuring methods thereof | |
| CN105973279B (en) | The single-ended reflective long-period fiber grating sensor of one kind and its manufacture craft | |
| Sultan et al. | Surface plasmon resonance based fiber optic sensor: theoretical simulation and experimental realization | |
| Qiu et al. | Plasmonic fiber-optic refractometers based on a high Q-factor amplitude interrogation | |
| Islam et al. | Novel SPR biosensor with simple PCF structure of hexagonal lattice operating in near-IR | |
| CN110823834B (en) | High-sensitivity SPR refractive index sensor based on plastic optical fiber periodic narrow groove structure | |
| CN111307742B (en) | Preparation method of enhanced guided-mode resonance optical fiber sensor | |
| Yin et al. | Experimental study of surface plasmon resonance refractive index sensor based on side-polished few-mode fiber | |
| CN112254840A (en) | Optical fiber SPR sensor for measuring magnetic field and temperature based on STS structure | |
| Bing et al. | Theoretical and experimental researches on a PCF-based SPR sensor | |
| Wang et al. | SPR Sensor Based on Cascaded NCF and U-Shaped Multimode Fibers for Simultaneous Detection of Refractive Index and Temperature | |
| US5812255A (en) | Process and device for determining the refractive index of different mediums | |
| Li et al. | Fiber cladding SPR sensor based on V-groove structure | |
| CN205664848U (en) | Single -ended reflective long period fiber grating sensor | |
| Shangguan et al. | Fabry–Perot cavity cascaded sagnac loops for temperature and strain measurements | |
| CN113624361A (en) | Optical fiber probe, temperature sensor and preparation method of optical fiber probe | |
| CN113029216B (en) | Multi-parameter sensor based on coaxial double waveguide fiber | |
| CN213632451U (en) | Optical fiber SPR sensor for measuring magnetic field and temperature based on STS structure | |
| CN117647326A (en) | SPR optical fiber sensing device of cascade MZI |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| TR01 | Transfer of patent right | ||
| TR01 | Transfer of patent right |
Effective date of registration: 20231108 Address after: 401329 No. 99, Xinfeng Avenue, Jinfeng Town, Gaoxin District, Jiulongpo District, Chongqing Patentee after: Chongqing Science City Intellectual Property Operation Center Co.,Ltd. Address before: 252059 No. 1, Dongchangfu, Liaocheng District, Shandong, Hunan Road Patentee before: LIAOCHENG University |