WO2009041745A1 - A temperature-sensitive and photo-sensitive fiber, a temperature-insensitive and photo-sensitive fiber, and an fiber sensor using the same - Google Patents
A temperature-sensitive and photo-sensitive fiber, a temperature-insensitive and photo-sensitive fiber, and an fiber sensor using the same Download PDFInfo
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- WO2009041745A1 WO2009041745A1 PCT/KR2007/004765 KR2007004765W WO2009041745A1 WO 2009041745 A1 WO2009041745 A1 WO 2009041745A1 KR 2007004765 W KR2007004765 W KR 2007004765W WO 2009041745 A1 WO2009041745 A1 WO 2009041745A1
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- Prior art keywords
- temperature
- photosensitive
- dopant
- optical fiber
- sensitive
- Prior art date
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- 239000000835 fiber Substances 0.000 title claims description 52
- 239000013307 optical fiber Substances 0.000 claims abstract description 88
- 239000002019 doping agent Substances 0.000 claims abstract description 55
- 238000005253 cladding Methods 0.000 claims abstract description 11
- 206010034972 Photosensitivity reaction Diseases 0.000 claims description 23
- 230000036211 photosensitivity Effects 0.000 claims description 23
- 239000011734 sodium Substances 0.000 claims description 18
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 12
- 239000010936 titanium Substances 0.000 claims description 12
- WKBOTKDWSSQWDR-UHFFFAOYSA-N Bromine atom Chemical compound [Br] WKBOTKDWSSQWDR-UHFFFAOYSA-N 0.000 claims description 9
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 9
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 claims description 9
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 claims description 9
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 claims description 9
- 229910052796 boron Inorganic materials 0.000 claims description 9
- GDTBXPJZTBHREO-UHFFFAOYSA-N bromine Substances BrBr GDTBXPJZTBHREO-UHFFFAOYSA-N 0.000 claims description 9
- 229910052794 bromium Inorganic materials 0.000 claims description 9
- 239000001257 hydrogen Substances 0.000 claims description 9
- 229910052739 hydrogen Inorganic materials 0.000 claims description 9
- 229910052744 lithium Inorganic materials 0.000 claims description 9
- 229910052700 potassium Inorganic materials 0.000 claims description 9
- 239000011591 potassium Substances 0.000 claims description 9
- 229910052708 sodium Inorganic materials 0.000 claims description 9
- 229910052718 tin Inorganic materials 0.000 claims description 9
- ZOXJGFHDIHLPTG-UHFFFAOYSA-N Boron Chemical compound [B] ZOXJGFHDIHLPTG-UHFFFAOYSA-N 0.000 claims description 7
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 claims description 6
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 claims description 6
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 6
- 229910052787 antimony Inorganic materials 0.000 claims description 6
- WATWJIUSRGPENY-UHFFFAOYSA-N antimony atom Chemical compound [Sb] WATWJIUSRGPENY-UHFFFAOYSA-N 0.000 claims description 6
- 239000000460 chlorine Substances 0.000 claims description 6
- 239000010949 copper Substances 0.000 claims description 6
- 239000010931 gold Substances 0.000 claims description 6
- 229910052757 nitrogen Inorganic materials 0.000 claims description 6
- 229910052698 phosphorus Inorganic materials 0.000 claims description 6
- 239000011574 phosphorus Substances 0.000 claims description 6
- 229910052714 tellurium Inorganic materials 0.000 claims description 6
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 claims description 6
- 229910052719 titanium Inorganic materials 0.000 claims description 6
- 230000003247 decreasing effect Effects 0.000 claims description 5
- ZCYVEMRRCGMTRW-UHFFFAOYSA-N 7553-56-2 Chemical compound [I] ZCYVEMRRCGMTRW-UHFFFAOYSA-N 0.000 claims description 3
- 229910001369 Brass Inorganic materials 0.000 claims description 3
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 claims description 3
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052693 Europium Inorganic materials 0.000 claims description 3
- PXGOKWXKJXAPGV-UHFFFAOYSA-N Fluorine Chemical compound FF PXGOKWXKJXAPGV-UHFFFAOYSA-N 0.000 claims description 3
- 229910052778 Plutonium Inorganic materials 0.000 claims description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 3
- 229910052769 Ytterbium Inorganic materials 0.000 claims description 3
- 239000010951 brass Substances 0.000 claims description 3
- 229910052793 cadmium Inorganic materials 0.000 claims description 3
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 claims description 3
- 229910052792 caesium Inorganic materials 0.000 claims description 3
- TVFDJXOCXUVLDH-UHFFFAOYSA-N caesium atom Chemical compound [Cs] TVFDJXOCXUVLDH-UHFFFAOYSA-N 0.000 claims description 3
- 229910052801 chlorine Inorganic materials 0.000 claims description 3
- 229910052802 copper Inorganic materials 0.000 claims description 3
- OGPBJKLSAFTDLK-UHFFFAOYSA-N europium atom Chemical compound [Eu] OGPBJKLSAFTDLK-UHFFFAOYSA-N 0.000 claims description 3
- 229910052731 fluorine Inorganic materials 0.000 claims description 3
- 239000011737 fluorine Substances 0.000 claims description 3
- 229910052737 gold Inorganic materials 0.000 claims description 3
- 229910052738 indium Inorganic materials 0.000 claims description 3
- APFVFJFRJDLVQX-UHFFFAOYSA-N indium atom Chemical compound [In] APFVFJFRJDLVQX-UHFFFAOYSA-N 0.000 claims description 3
- 229910052740 iodine Inorganic materials 0.000 claims description 3
- 239000011630 iodine Substances 0.000 claims description 3
- WABPQHHGFIMREM-UHFFFAOYSA-N lead(0) Chemical compound [Pb] WABPQHHGFIMREM-UHFFFAOYSA-N 0.000 claims description 3
- QSHDDOUJBYECFT-UHFFFAOYSA-N mercury Chemical compound [Hg] QSHDDOUJBYECFT-UHFFFAOYSA-N 0.000 claims description 3
- OYEHPCDNVJXUIW-UHFFFAOYSA-N plutonium atom Chemical compound [Pu] OYEHPCDNVJXUIW-UHFFFAOYSA-N 0.000 claims description 3
- 229910052709 silver Inorganic materials 0.000 claims description 3
- 239000004332 silver Substances 0.000 claims description 3
- JBQYATWDVHIOAR-UHFFFAOYSA-N tellanylidenegermanium Chemical compound [Te]=[Ge] JBQYATWDVHIOAR-UHFFFAOYSA-N 0.000 claims description 3
- 229910052716 thallium Inorganic materials 0.000 claims description 3
- BKVIYDNLLOSFOA-UHFFFAOYSA-N thallium Chemical compound [Tl] BKVIYDNLLOSFOA-UHFFFAOYSA-N 0.000 claims description 3
- NAWDYIZEMPQZHO-UHFFFAOYSA-N ytterbium Chemical compound [Yb] NAWDYIZEMPQZHO-UHFFFAOYSA-N 0.000 claims description 3
- 239000011701 zinc Substances 0.000 claims description 3
- 230000007423 decrease Effects 0.000 abstract description 3
- 230000000052 comparative effect Effects 0.000 description 14
- 230000007547 defect Effects 0.000 description 11
- 229910052732 germanium Inorganic materials 0.000 description 11
- 238000000034 method Methods 0.000 description 9
- 238000000411 transmission spectrum Methods 0.000 description 7
- 230000035945 sensitivity Effects 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- 238000010521 absorption reaction Methods 0.000 description 5
- GNPVGFCGXDBREM-UHFFFAOYSA-N germanium atom Chemical compound [Ge] GNPVGFCGXDBREM-UHFFFAOYSA-N 0.000 description 5
- 238000006073 displacement reaction Methods 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 238000011068 loading method Methods 0.000 description 3
- 125000004429 atom Chemical group 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- YBMRDBCBODYGJE-UHFFFAOYSA-N germanium dioxide Chemical compound O=[Ge]=O YBMRDBCBODYGJE-UHFFFAOYSA-N 0.000 description 2
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 2
- 230000001678 irradiating effect Effects 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000005229 chemical vapour deposition Methods 0.000 description 1
- 229910052681 coesite Inorganic materials 0.000 description 1
- 229910052906 cristobalite Inorganic materials 0.000 description 1
- 230000002950 deficient Effects 0.000 description 1
- 238000005137 deposition process Methods 0.000 description 1
- 238000010891 electric arc Methods 0.000 description 1
- 239000004615 ingredient Substances 0.000 description 1
- 229910052745 lead Inorganic materials 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052753 mercury Inorganic materials 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 229910052710 silicon Chemical group 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 229910052682 stishovite Inorganic materials 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
- 229910052905 tridymite Inorganic materials 0.000 description 1
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
- G02B6/02—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
- G02B6/02114—Refractive index modulation gratings, e.g. Bragg gratings characterised by enhanced photosensitivity characteristics of the fibre, e.g. hydrogen loading, heat treatment
-
- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C13/00—Fibre or filament compositions
- C03C13/04—Fibre optics, e.g. core and clad fibre compositions
- C03C13/045—Silica-containing oxide glass compositions
- C03C13/046—Multicomponent glass compositions
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K11/00—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00
- G01K11/32—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres
- G01K11/3206—Measuring temperature based upon physical or chemical changes not covered by groups G01K3/00, G01K5/00, G01K7/00 or G01K9/00 using changes in transmittance, scattering or luminescence in optical fibres at discrete locations in the fibre, e.g. using Bragg scattering
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
- G01K5/00—Measuring temperature based on the expansion or contraction of a material
- G01K5/48—Measuring temperature based on the expansion or contraction of a material the material being a solid
Definitions
- the present invention relates to a photosensitive optical fiber and a fiber sensor using the same. More particularly, the present invention relates to photosensitive optical fibers which are respectively sensitive and insensitive to external temperature changes through additive substances existing in core regions of the photosensitive fibers, and a fiber sensor using the same.
- Photosensitivity refers to a change in refractive index of an optical fiber due to UV laser. Particularly, photosensitive optical fibers have frequently been used to conduct studies on a variety of devices such as fiber sensors, fiber filters.
- a hydrogen loading method is frequently used to improve photosensitivity of optical fibers.
- the hydrogen loading method has problems that it takes much time in hydrogenating, and it is dangerous due to hydrogenating at a high temperature and pressure, and further it is difficult to attach hydrogenated optical fibers using arc discharge.
- such a photosensitive optical fiber is generally an effective fiber in forming a short-period or a long-period fiber grating.
- the short-period or the long- period fiber gratings formed in the photosensitive optical fiber have external dependencies in which its refractive index is changed depending on an external factor such as an external temperature, a tensile force, a compressive force, torsion or displacement, the movement of a fiber grating formed at a specific wavelength is induced in accordance with such external dependencies, thereby serving as a sensor in various fields.
- a variable related to a change in external temperature is excluded in a sensor for sensing a tensile force, a compressive force, torsion, displacement or the like.
- a fiber sensor system is used as fiber sensor for a factor such as a tensile force, a compressive force, a torsion, a displacement or the like, through its own complicated calculation process by applying a variable for the temperature change sensed in the fiber sensor system, or through its own compensation process for the temperature change with new reference fiber gratings, in order to make effects of this external temperature change negligible.
- These processes are responsible for the rise in unit cost, and they are inefficient as well as complicated in a developing process.
- the present invention has been made in an effort to solve the problems occurring in the prior art, and it is an object of the present invention to provide a temperature-sensitive and photosensitive optical fiber having sensitivity to a change in external temperature.
- a temperature-sensitive and photosensitive optical fiber comprising a core region and a cladding region, wherein the core region is codoped with a photosensitive dopant and a temperature-sensitive dopant, the photosensitive dopant changing a refractive index of the core region by UV laser irradiation, and the temperature-sensitive dopant increasing a thermal expansion coefficient of the core region.
- the photosensitive dopant may be Ge.
- the photosensitive dopant may include at least one selected from the group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity.
- the photosensitive dopant may include at least one selected from the group consisting of cesium (Cs), potassium (K), sodium (Na), mercury (Hg), plutonium (Pu), lithium (Li), europium (Eu), indium (In), cadmium (Cd), zinc (Zn), thallium (Tl), ytterbium (Yb), plumbum (Pb), alluminum (Al), copper (Cu), brass (Cu+Zn), silver (Ag) and gold (Au).
- a temperature-sensitive fiber sensor comprising a short-period or long-period fiber grating formed in the core region by irradiating the temperature-sensitive and photosensitive optical fiber with UV laser.
- a temperature-insensitive and photosensitive optical fiber comprising a core region and a cladding region, wherein the core region is codoped with a photosensitive dopant and a temperature-insensitive dopant, the photosensitive dopant changing a refractive index of the core region by UV laser irradiation, and the temperature-insensitive dopant decreasing a thermal expansion coefficient of the core region.
- the photosensitive dopant may be Ge.
- the photosensitive dopant may include at least one selected from the group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity.
- the temperature-insensitive dopant may include at least one selected from the group consisting of boron (B), fluorine (F), chlorine (Cl), bromine (Br) and iodine
- a temperature-insensitive fiber sensor comprising a short-period or long-period fiber grating formed in the core region by irradiating the temperature-insensitive and photosensitive optical fiber with UV laser.
- a short-period or a long-period fiber grating can be formed without the conventional hydrogen loading method, so that it is advantageous in temporal, economical and safe aspects.
- the present invention has a low manufacturing cost, a simple configuration and efficiency, and it can provide a photosensitive optical fiber having sensitivity or in- sensitivity to a change in external temperature while having a superior photosensitivity to the conventional photosensitive optical fiber.
- FIG. 1 is a view showing the configuration of an external temperature experiment according to a Comparative Example and Examples 1 and 2 of the present invention
- Fig. 2 is a graph showing transmission spectra of a Ge/Sn-doped fiber according to the Comparative Example, in which a short-period fiber grating is formed, depending on changes in temperature;
- Fig. 3 is a graph showing transmission spectra of a Ge/Pb/Sn-doped fiber according to Example 1 of the present invention, in which a short-period fiber grating is formed, depending on changes in temperature;
- Fig. 4 is a graph showing transmission spectra of a Ge/B/Sn-doped fiber according to
- Example 2 of the present invention in which a short-period fiber grating is formed, depending on changes in temperature
- Fig. 5 is a graph showing transmission spectra of the photosensitive optical fibers according to the Comparative Example and Examples 1 and 2 of the present invention, depending on changes in temperature. Mode for the Invention
- the present inventors have developed a photosensitive optical fiber having sensitivity or insensitivity to a change in external temperature by allowing a novel photosensitive material for improving photosensitivity and a novel temperature-sensitive or temperature insensitive codopant to be contained in a existing photosensitive optical fiber.
- a temperature-sensitive and photosensitive optical fiber comprises a core region and a cladding region.
- the core region is codoped with a photosensitive dopant and a temperature sensitive dopant.
- the photosensitive dopant changes a refractive index of the core region by UV laser irradiation, and the temperature- sensitive dopant increases a thermal expansion coefficient of the core region.
- the photosensitive dopant is Ge. More preferably, the photosensitive dopant includes at least one selected from the group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity.
- tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te) so as to improve photosensitivity.
- a degree of change in refractive index by UV laser irradiation i.e., photosensitivity of the core region is considerably improved, so that a short-period or long-period fiber grating having superior quality can be more easily formed in the temperature-sensitive and photosensitive optical fiber.
- the temperature-sensitive dopant preferably includes at least one selected from the group consisting of cesium (Cs), potassium (K), sodium (Na), hydrargyrum (Hg), plutonium (Pu), lithium (Li), europium (Eu), indium (In), cadmium (Cd), zinc (Zn), thallium (Tl), ytterbium (Yb), plumbum (Pb), alluminum (Al), copper (Cu), brass (Cu+Zn), silver (Ag) and gold (Au).
- temperature-sensitive and photosensitive optical fiber can measure a degree of change in external temperature from the degree of change in period of the short-period or long-period fiber grating formed in the temperature-sensitive and photosensitive optical fiber.
- a temperature-insensitive and photosensitive optical fiber comprises a core region and a cladding region.
- the core region is codoped with a photosensitive dopant and a temperature-insensitive dopant.
- the photosensitive dopant changes a refractive index of the core region by UV laser irradiation, and the temperature-insensitive dopant decreases a thermal expansion coefficient of the core region.
- the photosensitive dopant is Ge. More preferably, the photosensitive dopant includes at least one selected from the group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity.
- tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te) so as to improve photosensitivity.
- a degree of change in refractive index by UV laser irradiation i.e., photosensitivity of the core region is considerably improved, so that a short-period or long-period fiber grating having superior quality can be more easily formed in the temperature-insensitive and photosensitive optical fiber.
- the temperature-insensitive dopant preferably includes at least one selected from the group consisting of boron (B), fluorine (F), chlorine (Cl), bromine (Br) and iodine (I).
- the temperature-insensitive dopant is codoped into the temperature-insensitive and photosensitive optical fiber, so that a degree of change in period of the short-period or long-period fiber grating previously formed in the temperature-insensitive and photosensitive optical fiber is decreased depending on changes in external temperature.
- the degree of change in period of the short-period or the long-period fiber grating formed in the temperature-insensitive and photosensitive optical fiber in accordance with changes in external temperature can be neglected.
- An optical fiber codoped with germanium (Ge) and boron (B) has very great photosensitivity, for which a method of doping Ge and B together in a core deposition process of modified chemical vapor deposition (MCVD) is frequently used.
- MCVD modified chemical vapor deposition
- germanium (Ge) increases a refractive index and also has a positive temperature dependency (dn/dT>0)
- boron (B) increases a refractive index and also has a negative temperature dependency (dn/dT ⁇ 0).
- the photosensitivity of an optical fiber is a characteristic by Ge existing in a core region of the optical fiber, which enables a fiber grating to be more effectively formed in the core region of the optical fiber by irradiation of UV laser of KrF having a wavelength of 248nm.
- the fiber grating stands for a regular refractive-index change pattern generated by a change in refractive index to be caused depending on a degree of exposure as an optical fiber having photosensitivity is exposed to UV laser for a certain time.
- the photosensitivity is generated not by simple addition of Ge to an optical fiber but by the Ge-O defect in the core region of the optical fiber.
- the Ge-O defect is a substance generated by an inverse reaction accompanied by a chemical reaction in which GeO is intended to be generated. That is, in an ideal fiber, a refractive index is changed by adding GeO to a SiO base, while, in a photosensitive optical fiber, Ge-O defects are generated in a process of producing GeO , and these are reacted at their specific wavelengths (195nm, 248nm, 350nm and the like). Therefore, the photosensitivity by laser is generally a phenomenon observed in an optical fiber to which Ge is added.
- Quartz glass (SiO ) to be ingredient for optical fiber has an amorphous form in which a tetrahedral structure is formed in a net shape, and has an absorption band near 160nm.
- germanium When germanium is added to the quartz glass, GeO having the same structure as that of SiO exists in the quartz glass, and a Ge-O defect (Oxygen Deficient Germanium) is generated depending on an amount of GeO used when manufacturing a preform.
- the Ge-O defect When the Ge-O defect is generated, it results in a structure where a Ge atom is bonded with three oxygen atoms and a Ge or Si atom.
- This Ge-O defect has an absorption band having a center wavelength of 240nm and a bandwidth of 30nm, and the photosensitivity shown in an optical fiber containing Ge is observed near 240nm or in a visible region (about 480nm) having the maximum absorption of two photons at 240nm. Therefore, studies on the photosensitivity have been mainly conducted through the relation between an absorption band of 240nm generated by the Ge-O defect and a change in refractive index of a core region of an optical fiber.
- a photosensitive optical fiber is manufactured by doping a core region of an optical fiber with Ge and Sn so as to have a core composition in Table 1 using an MCVD method. Then, FBG having a predetermined pattern is formed by UV laser irradiation with a specific wavelength in the photosensitive optical fiber of Comparative Example. Thereafter, the photosensitive optical fiber of Comparative Example is tested for dependencies in accordance with changes in external temperature through an external temperature experiment configured as shown in Fig. 1.
- Example 1 (temperature-sensitive and photosensitive optical fiber)
- Example 1 of the present invention a temperature-sensitve and photosensitive optical fiber is manufactured by doping a core region of an optical fiber with Ge, Sn and Pb so as to have a core composition in Table 1 using an MCVD method. Then, FBG having the same pattern as that of the Comparative Example is formed by UV laser irradiation with a specific wavelength in the temperature-sensitive and photosensitive optical fiber of Example 1 of the present invention. Thereafter, it is tested for dependencies in accordance with changes in external temperature through the external temperature experiment configured as shown in Fig. 1.
- Example 2 (temperature-insensitive and photosensitive optical fiber)
- a temperature-insensitive and photosensitive optical fiber is manufactured by doping a core region of an optical fiber with Ge, Sn and B so as to have a core composition in Table 1 using an MCVD method. Then, FBG having the same pattern as that of the Comparative Example is formed by UV laser irradiation with a specific wavelength in the temperature-insensitive and photosensitive optical fiber of Example 2 of the present invention. Thereafter, it is tested for dependencies in accordance with changes in external temperature through the external temperature experiment configured as shown in Fig. 1.
- Figs. 2 to 4 are graphs respectively showing transmission spectra of a photosensitive optical fiber (Ge/Sn-doped photosensitive optical fiber) of the Comparative Example, in which a short-period fiber grating is formed, depending on changes in external temperature; transmission spectra of a temperature-sensitive and photosensitive optical fiber (Ge/Pb/Sn-doped photosensitive optical fiber) Example 1 of the present invention, in which a short-period fiber grating is formed, depending on changes in temperature; and transmission spectra of a temperature-insensitive and photosensitive optical fiber (Ge/B/Sn-doped photosensitive optical fiber) of Example 2 of the present invention, in which a short-period fiber grating is formed, depending on changes in temperature.
- Example 1 of the present invention has the largest temperature sensitivity
- Example 2 of the present invention has the least temperature insensitivity.
- Example 1 of the present invention Pb is doped as a dopant increasing a thermal expansion coefficient of the core region, so that line and volume expansion rates are increased in accordance with increases of temperature. Therefore, a change in period of a short-period fiber grating formed in the core region is shown larger than those in the Comparative Example and Example 2 of the present invention, to which Pb is not added.
- Example 2 of the present invention B is doped as a dopant decreasing a thermal expansion coefficient of the core region, so that line and volume expansion rates are decreased in accordance with increases of temperature. Therefore, a change in period of a short-period fiber grating formed in the core region is shown larger than those in the Comparative Example and Example 1 of the present invention, to which B is not added.
- Example 2 of the present invention as the boron (B) decreases a refractive index, single-mode conditions can be satisfied by adding a larger amount of Ge than those in the Comparative Example and Examples 1 of the present invention. At this time, a Ge- O defect is increased due to the more largely added Ge, thereby improving photosensitivity of an optical fiber.
- Fig. 5 is a graph showing wavelength movements of short-period fiber gratings of the photosensitive optical fibers in accordance with changes in temperature as the results of Figs. 2 to 4.
- the temperature-sensitive fiber containing Pb has about 1.33nm/60°C of wavelength movement per temperature, which shows a large difference from that of the conventional photosensitive optical fiber
- the temperature-insensitive fiber containing boron (B) has about 1.33nm/60°C of wavelength movement per temperature.
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- Chemical Kinetics & Catalysis (AREA)
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- Materials Engineering (AREA)
- Organic Chemistry (AREA)
- Measuring Temperature Or Quantity Of Heat (AREA)
Abstract
There is provided a temperature- sensitive and photosensitive optical fiber comprising a core region and a cladding region. The core region is codoped with a photosensitive dopant and a temperature sensitive dopant. The photosensitive dopant changes a refractive index of the core region by UV laser irradiation, and the temperature- sensitive dopant increases a thermal expansion coefficient of the core region. Further, there is provided a temperature-insensitive and photosensitive optical fiber comprising a core region and a cladding region. The core region is codoped with a photosensitive dopant and a temperature-insensitive dopant. The photosensitive dopant changes a refractive index of the core region by UV laser irradiation, and the temperature-insensitive dopant decreases a thermal expansion coefficient of the core region.
Description
Description
A TEMPERATURE-SENSITIVE AND PHOTO-SENSITIVE FIBER, A TEMPERATURE-INSENSITIVE AND PHOTOSENSITIVE FIBER, AND AN FIBER SENSOR USING THE
SAME Technical Field
[1] The present invention relates to a photosensitive optical fiber and a fiber sensor using the same. More particularly, the present invention relates to photosensitive optical fibers which are respectively sensitive and insensitive to external temperature changes through additive substances existing in core regions of the photosensitive fibers, and a fiber sensor using the same. Background Art
[2] Photosensitivity refers to a change in refractive index of an optical fiber due to UV laser. Particularly, photosensitive optical fibers have frequently been used to conduct studies on a variety of devices such as fiber sensors, fiber filters.
[3] A hydrogen loading method is frequently used to improve photosensitivity of optical fibers. However, the hydrogen loading method has problems that it takes much time in hydrogenating, and it is dangerous due to hydrogenating at a high temperature and pressure, and further it is difficult to attach hydrogenated optical fibers using arc discharge.
[4] On the other hand, such a photosensitive optical fiber is generally an effective fiber in forming a short-period or a long-period fiber grating. The short-period or the long- period fiber gratings formed in the photosensitive optical fiber have external dependencies in which its refractive index is changed depending on an external factor such as an external temperature, a tensile force, a compressive force, torsion or displacement, the movement of a fiber grating formed at a specific wavelength is induced in accordance with such external dependencies, thereby serving as a sensor in various fields.
[5] Therefore, a variable related to a change in external temperature is excluded in a sensor for sensing a tensile force, a compressive force, torsion, displacement or the like. Conventionally, a fiber sensor system is used as fiber sensor for a factor such as a tensile force, a compressive force, a torsion, a displacement or the like, through its own complicated calculation process by applying a variable for the temperature change sensed in the fiber sensor system, or through its own compensation process for the temperature change with new reference fiber gratings, in order to make effects of this
external temperature change negligible. These processes are responsible for the rise in unit cost, and they are inefficient as well as complicated in a developing process.
[6] On the contrary, in order to measure a change in external temperature only, excluding external physical factors such as a tensile force, a compressive force, a torsion and a displacement, it is urgently needed to develop a temperature-sensitive and photosensitive optical fiber which can serve as sensor to measure the change in the external temperature using the change in refractive index of fiber gratings already formed in the sensor according to the change in the external temperature, excluding the above external physical factors. Disclosure of Invention Technical Problem
[7] Accordingly, the present invention has been made in an effort to solve the problems occurring in the prior art, and it is an object of the present invention to provide a temperature-sensitive and photosensitive optical fiber having sensitivity to a change in external temperature.
[8] It is another object of the present invention to provide a temperature-sensitive and photosensitive optical fiber having sensitivity to a change in external temperature while having improved photosensitivity.
[9] It is still another object of the present invention to provide a fiber sensor using the temperature-sensitive and photosensitive optical fiber.
[10] It is still another object of the present invention to provide a temperature-insensitive and photosensitive optical fiber having insensitivity to a change in external temperature.
[11] It is still another object of the present invention to provide a temperature-insensitive and photosensitive optical fiber having insensitivity to a change in external temperature while having improved photosensitivity.
[12] It is still another object of the present invention to provide a fiber sensor using the temperature-insensitive and photosensitive optical fiber. Technical Solution
[13] According to an aspect of the present invention, there is provided a temperature- sensitive and photosensitive optical fiber comprising a core region and a cladding region, wherein the core region is codoped with a photosensitive dopant and a temperature-sensitive dopant, the photosensitive dopant changing a refractive index of the core region by UV laser irradiation, and the temperature-sensitive dopant increasing a thermal expansion coefficient of the core region.
[14] Preferably, the photosensitive dopant may be Ge.
[15] Preferably, the photosensitive dopant may include at least one selected from the
group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity.
[16] Preferably, the photosensitive dopant may include at least one selected from the group consisting of cesium (Cs), potassium (K), sodium (Na), mercury (Hg), plutonium (Pu), lithium (Li), europium (Eu), indium (In), cadmium (Cd), zinc (Zn), thallium (Tl), ytterbium (Yb), plumbum (Pb), alluminum (Al), copper (Cu), brass (Cu+Zn), silver (Ag) and gold (Au).
[17] According to another aspect of the present invention, there is provided a temperature- sensitive fiber sensor comprising a short-period or long-period fiber grating formed in the core region by irradiating the temperature-sensitive and photosensitive optical fiber with UV laser.
[18] According to still another aspect of the present invention, there is provided a temperature-insensitive and photosensitive optical fiber comprising a core region and a cladding region, wherein the core region is codoped with a photosensitive dopant and a temperature-insensitive dopant, the photosensitive dopant changing a refractive index of the core region by UV laser irradiation, and the temperature-insensitive dopant decreasing a thermal expansion coefficient of the core region.
[19] Preferably, the photosensitive dopant may be Ge.
[20] Preferably, the photosensitive dopant may include at least one selected from the group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity.
[21] Preferably, the temperature-insensitive dopant may include at least one selected from the group consisting of boron (B), fluorine (F), chlorine (Cl), bromine (Br) and iodine
(I). [22] According to still another aspect of the present invention, there is provided a temperature-insensitive fiber sensor comprising a short-period or long-period fiber grating formed in the core region by irradiating the temperature-insensitive and photosensitive optical fiber with UV laser.
Advantageous Effects
[23] According to the present invention, there are advantages as follows:
[24] First, in the present invention, a short-period or a long-period fiber grating can be formed without the conventional hydrogen loading method, so that it is advantageous in temporal, economical and safe aspects. [25] Second, the present invention has a low manufacturing cost, a simple configuration and efficiency, and it can provide a photosensitive optical fiber having sensitivity or in-
sensitivity to a change in external temperature while having a superior photosensitivity to the conventional photosensitive optical fiber. Brief Description of the Drawings
[26] The above and other objects, features and advantages of the present invention will become apparent from the following description of Examples given in conjunction with the accompanying drawings, in which:
[27] Fig. 1 is a view showing the configuration of an external temperature experiment according to a Comparative Example and Examples 1 and 2 of the present invention;
[28] Fig. 2 is a graph showing transmission spectra of a Ge/Sn-doped fiber according to the Comparative Example, in which a short-period fiber grating is formed, depending on changes in temperature;
[29] Fig. 3 is a graph showing transmission spectra of a Ge/Pb/Sn-doped fiber according to Example 1 of the present invention, in which a short-period fiber grating is formed, depending on changes in temperature;
[30] Fig. 4 is a graph showing transmission spectra of a Ge/B/Sn-doped fiber according to
Example 2 of the present invention, in which a short-period fiber grating is formed, depending on changes in temperature; and
[31] Fig. 5 is a graph showing transmission spectra of the photosensitive optical fibers according to the Comparative Example and Examples 1 and 2 of the present invention, depending on changes in temperature. Mode for the Invention
[32] Hereinafter, the Examples of the present invention will be described in detail with reference to accompanying drawings.
[33] The present inventors have developed a photosensitive optical fiber having sensitivity or insensitivity to a change in external temperature by allowing a novel photosensitive material for improving photosensitivity and a novel temperature-sensitive or temperature insensitive codopant to be contained in a existing photosensitive optical fiber.
[34] First, a temperature-sensitive and photosensitive optical fiber according to the present invention comprises a core region and a cladding region. The core region is codoped with a photosensitive dopant and a temperature sensitive dopant. Here, the photosensitive dopant changes a refractive index of the core region by UV laser irradiation, and the temperature- sensitive dopant increases a thermal expansion coefficient of the core region.
[35] Preferably, the photosensitive dopant is Ge. More preferably, the photosensitive dopant includes at least one selected from the group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium
(Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity. Through such a constitution, a degree of change in refractive index by UV laser irradiation, i.e., photosensitivity of the core region is considerably improved, so that a short-period or long-period fiber grating having superior quality can be more easily formed in the temperature-sensitive and photosensitive optical fiber.
[36] Further, the temperature-sensitive dopant preferably includes at least one selected from the group consisting of cesium (Cs), potassium (K), sodium (Na), hydrargyrum (Hg), plutonium (Pu), lithium (Li), europium (Eu), indium (In), cadmium (Cd), zinc (Zn), thallium (Tl), ytterbium (Yb), plumbum (Pb), alluminum (Al), copper (Cu), brass (Cu+Zn), silver (Ag) and gold (Au). The temperature- sensitive dopant is codoped into the core region of the temperature-sensitive and photosensitive optical fiber, so that a degree of change in period of the short-period or long-period fiber grating previously formed in the temperature-sensitive and photosensitive optical fiber is increased depending on changes in external temperature. Accordingly, temperature-sensitive and photosensitive optical fiber according to the present invention can measure a degree of change in external temperature from the degree of change in period of the short-period or long-period fiber grating formed in the temperature-sensitive and photosensitive optical fiber.
[37] Next, a temperature-insensitive and photosensitive optical fiber according to the present invention comprises a core region and a cladding region. The core region is codoped with a photosensitive dopant and a temperature-insensitive dopant. Here, the photosensitive dopant changes a refractive index of the core region by UV laser irradiation, and the temperature-insensitive dopant decreases a thermal expansion coefficient of the core region.
[38] Preferably, the photosensitive dopant is Ge. More preferably, the photosensitive dopant includes at least one selected from the group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity. Through such a constitution, a degree of change in refractive index by UV laser irradiation, i.e., photosensitivity of the core region is considerably improved, so that a short-period or long-period fiber grating having superior quality can be more easily formed in the temperature-insensitive and photosensitive optical fiber.
[39] Further, the temperature-insensitive dopant preferably includes at least one selected from the group consisting of boron (B), fluorine (F), chlorine (Cl), bromine (Br) and iodine (I). The temperature-insensitive dopant is codoped into the temperature-insensitive and photosensitive optical fiber, so that a degree of change in period of the short-period or long-period fiber grating previously formed in the temperature-insensitive and photosensitive optical fiber is decreased depending on changes in
external temperature. Accordingly, in the temperature-insensitive and photosensitive optical fiber according to the present invention, the degree of change in period of the short-period or the long-period fiber grating formed in the temperature-insensitive and photosensitive optical fiber in accordance with changes in external temperature can be neglected.
[40] An optical fiber codoped with germanium (Ge) and boron (B) has very great photosensitivity, for which a method of doping Ge and B together in a core deposition process of modified chemical vapor deposition (MCVD) is frequently used.
[41] The present inventors have found that while germanium (Ge) increases a refractive index and also has a positive temperature dependency (dn/dT>0), boron (B) increases a refractive index and also has a negative temperature dependency (dn/dT<0).
[42] Generally, the photosensitivity of an optical fiber is a characteristic by Ge existing in a core region of the optical fiber, which enables a fiber grating to be more effectively formed in the core region of the optical fiber by irradiation of UV laser of KrF having a wavelength of 248nm.
[43] The fiber grating stands for a regular refractive-index change pattern generated by a change in refractive index to be caused depending on a degree of exposure as an optical fiber having photosensitivity is exposed to UV laser for a certain time.
[44] When a photosensitive optical fiber having a core region doped with germanium (Ge) is exposed to UV laser, a bond of GeO2 constituting a network structure together with SiO2 in the core region of the photosensitive optical fiber, is broken, and a Ge-O defect is formed, which causes a change in refractive index and since a Ge component does not exist in a cladding region of the photosensitive region, the change in refractive index therein can be neglected as compared with that in the core region.
[45] Therefore, the photosensitivity is generated not by simple addition of Ge to an optical fiber but by the Ge-O defect in the core region of the optical fiber. The Ge-O defect is a substance generated by an inverse reaction accompanied by a chemical reaction in which GeO is intended to be generated. That is, in an ideal fiber, a refractive index is changed by adding GeO to a SiO base, while, in a photosensitive optical fiber, Ge-O defects are generated in a process of producing GeO , and these are reacted at their specific wavelengths (195nm, 248nm, 350nm and the like). Therefore, the photosensitivity by laser is generally a phenomenon observed in an optical fiber to which Ge is added.
[46] Pure quartz glass (SiO ) to be ingredient for optical fiber has an amorphous form in which a tetrahedral structure is formed in a net shape, and has an absorption band near 160nm. When germanium is added to the quartz glass, GeO having the same structure as that of SiO exists in the quartz glass, and a Ge-O defect (Oxygen Deficient Germanium) is generated depending on an amount of GeO used when manufacturing
a preform. When the Ge-O defect is generated, it results in a structure where a Ge atom is bonded with three oxygen atoms and a Ge or Si atom.
[47] This Ge-O defect has an absorption band having a center wavelength of 240nm and a bandwidth of 30nm, and the photosensitivity shown in an optical fiber containing Ge is observed near 240nm or in a visible region (about 480nm) having the maximum absorption of two photons at 240nm. Therefore, studies on the photosensitivity have been mainly conducted through the relation between an absorption band of 240nm generated by the Ge-O defect and a change in refractive index of a core region of an optical fiber.
[48] Recently, it has been observed that an absorption peak disappears near 240nm by strong UV light irradiation. Incident UV light breaks bonding of the Ge-O defect and forms a Ge-e defect to cause a change in refractive index. Such change in refractive index in the cladding region of the optical fiber can be almost neglected as compared with that in a core region of the optical fiber, since a Ge component does not exist in a cladding region of an optical fiber.
[49] Thus, in the present invention, various dopants besides Ge are added to the core region of the optical fiber so as to improve photosensitivity.
[50]
[51] Comparative Example
[52] As Comparative Example for comparison with Examples of the present invention, a photosensitive optical fiber is manufactured by doping a core region of an optical fiber with Ge and Sn so as to have a core composition in Table 1 using an MCVD method. Then, FBG having a predetermined pattern is formed by UV laser irradiation with a specific wavelength in the photosensitive optical fiber of Comparative Example. Thereafter, the photosensitive optical fiber of Comparative Example is tested for dependencies in accordance with changes in external temperature through an external temperature experiment configured as shown in Fig. 1.
[53]
[54] Example 1 (temperature-sensitive and photosensitive optical fiber)
[55] As Example 1 of the present invention, a temperature-sensitve and photosensitive optical fiber is manufactured by doping a core region of an optical fiber with Ge, Sn and Pb so as to have a core composition in Table 1 using an MCVD method. Then, FBG having the same pattern as that of the Comparative Example is formed by UV laser irradiation with a specific wavelength in the temperature-sensitive and photosensitive optical fiber of Example 1 of the present invention. Thereafter, it is tested for dependencies in accordance with changes in external temperature through the external temperature experiment configured as shown in Fig. 1.
[56]
[57] Example 2(temperature-insensitive and photosensitive optical fiber) [58] As Example 2 of the present invention, a temperature-insensitive and photosensitive optical fiber is manufactured by doping a core region of an optical fiber with Ge, Sn and B so as to have a core composition in Table 1 using an MCVD method. Then, FBG having the same pattern as that of the Comparative Example is formed by UV laser irradiation with a specific wavelength in the temperature-insensitive and photosensitive optical fiber of Example 2 of the present invention. Thereafter, it is tested for dependencies in accordance with changes in external temperature through the external temperature experiment configured as shown in Fig. 1.
[59] Table 1 [Table 1] [Table ]
Core composition comparison of photosensitive optical fibers according to Comparative Example, and Examples 1 and 2 of the present invention
[60] Figs. 2 to 4 are graphs respectively showing transmission spectra of a photosensitive optical fiber (Ge/Sn-doped photosensitive optical fiber) of the Comparative Example, in which a short-period fiber grating is formed, depending on changes in external temperature; transmission spectra of a temperature-sensitive and photosensitive optical fiber (Ge/Pb/Sn-doped photosensitive optical fiber) Example 1 of the present invention, in which a short-period fiber grating is formed, depending on changes in temperature; and transmission spectra of a temperature-insensitive and photosensitive optical fiber (Ge/B/Sn-doped photosensitive optical fiber) of Example 2 of the present invention, in which a short-period fiber grating is formed, depending on changes in temperature. As shown in these figures, Example 1 of the present invention has the largest temperature sensitivity, and Example 2 of the present invention has the least temperature insensitivity.
[61] In Example 1 of the present invention, Pb is doped as a dopant increasing a thermal expansion coefficient of the core region, so that line and volume expansion rates are increased in accordance with increases of temperature. Therefore, a change in period of
a short-period fiber grating formed in the core region is shown larger than those in the Comparative Example and Example 2 of the present invention, to which Pb is not added.
[62] On the contrary, in Example 2 of the present invention, B is doped as a dopant decreasing a thermal expansion coefficient of the core region, so that line and volume expansion rates are decreased in accordance with increases of temperature. Therefore, a change in period of a short-period fiber grating formed in the core region is shown larger than those in the Comparative Example and Example 1 of the present invention, to which B is not added.
[63] In Example 2 of the present invention, as the boron (B) decreases a refractive index, single-mode conditions can be satisfied by adding a larger amount of Ge than those in the Comparative Example and Examples 1 of the present invention. At this time, a Ge- O defect is increased due to the more largely added Ge, thereby improving photosensitivity of an optical fiber.
[64] Fig. 5 is a graph showing wavelength movements of short-period fiber gratings of the photosensitive optical fibers in accordance with changes in temperature as the results of Figs. 2 to 4. As shown in this figure, the temperature-sensitive fiber containing Pb has about 1.33nm/60°C of wavelength movement per temperature, which shows a large difference from that of the conventional photosensitive optical fiber, and the temperature-insensitive fiber containing boron (B) has about 1.33nm/60°C of wavelength movement per temperature.
[65] Those skilled in the art will appreciate that the conceptions and specific embodiments disclosed in the foregoing description may be readily utilized as a basis for modifying or designing other embodiments for carrying out the same purposes of the present invention. Those skilled in the art will also appreciate that such equivalent embodiments do not depart from the spirit and scope of the invention as set forth in the appended claims.
Claims
[1] A temperature- sensitive and photosensitive optical fiber comprisinga core region and a cladding region, wherein the core region is codoped with a photosensitive dopant and a temperature-sensitive dopant, the photosensitive dopant changing a refractive index of the core region by UV laser irradiation, and the temperature- sensitive dopant increasing a thermal expansion coefficient of the core region.
[2] The temperature-sensitive and photosensitive optical fiber of claim 1, wherein the photosensitive dopant is Ge.
[3] The temperature-sensitive and photosensitive optical fiber of claim 1, wherein the photosensitive dopant includes at least one selected from the group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity.
[4] The temperature-sensitive and photosensitive optical fiber of claim 1, wherein the temperature- sensitive dopant includes at least one selected from the group consisting of cesium (Cs), potassium (K), sodium (Na), hydrargyrum (Hg), plutonium (Pu), lithium (Li), europium (Eu), indium (In), cadmium (Cd), zinc (Zn), thallium (Tl), ytterbium (Yb), plumbum (Pb), alluminum (Al), copper(Cu), brass (Cu+Zn), silver (Ag) and gold(Au).
[5] A temperature- sensitive fiber sensor comprising a short-period or a long-period fiber grating formed in the core region by UV laser irradiation onto the temperature-sensitive and photosensitive optical fiber according to any one of claims 1 to 4.
[6] A temperature-insensitive and photosensitive optical fiber comprising a core region and a cladding region, wherein the core region is codoped with a photosensitive dopant and a temperature-insensitive dopant, the photosensitive dopant changing a refractive index of the core region by UV laser irradiation, and the temperature-insensitive dopant decreasing a thermal expansion coefficient of the core region.
[7] The temperature-insensitive and photosensitive optical fiber of claim 6, wherein the photosensitive dopant is Ge.
[8] The temperature-insensitive and photosensitive optical fiber of claim 6, wherein the photosensitive dopant includes at least one selected from the group consisting of tin (Sn), titanium (Ti), bromine (Br), nitrogen (N), phosphorus (P), hydrogen (H), lithium (Li), sodium (Na), potassium (K), antimony (Sb) and tellurium (Te), so as to improve photosensitivity.
[9] The temperature-insensitive and photosensitive optical fiber of claim 6, wherein
the temperature-insensitive dopant includes at least one selected from the group consisting of boron (B), fluorine (F), chlorine (Cl), bromine (Br) and iodine (I). [10] A temperature-insensitive fiber sensor comprising a short-period or long-period fiber grating formed in the core region by UV laser irradiation onto the temperature-insensitive and photosensitive optical fiber according to any one of claims 6 to 9.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/KR2007/004765 WO2009041745A1 (en) | 2007-09-28 | 2007-09-28 | A temperature-sensitive and photo-sensitive fiber, a temperature-insensitive and photo-sensitive fiber, and an fiber sensor using the same |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| PCT/KR2007/004765 WO2009041745A1 (en) | 2007-09-28 | 2007-09-28 | A temperature-sensitive and photo-sensitive fiber, a temperature-insensitive and photo-sensitive fiber, and an fiber sensor using the same |
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| WO2009041745A1 true WO2009041745A1 (en) | 2009-04-02 |
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|---|---|---|---|---|
| KR20000009570A (en) * | 1998-07-27 | 2000-02-15 | 이계철 | Optical fiber grating with temperature compensation |
| KR20020010903A (en) * | 1999-04-30 | 2002-02-06 | 앤더슨 데릭 제이. | Method for creating an optical structure within a photosensitive light transmissive material and of enhancing the photosensitivity of the photosensitive light transmissive material |
| US6578388B1 (en) * | 1995-08-29 | 2003-06-17 | Arroyo Optics Inc. | Grating assisted coupler devices |
| KR20030053033A (en) * | 2001-12-21 | 2003-06-27 | 제이에스알 가부시끼가이샤 | Radiation Sensitive Refractive Index Changing Composition and Refractive Index Changing Method |
| JP2004029691A (en) * | 2002-05-07 | 2004-01-29 | Furukawa Electric Co Ltd:The | Fiber grating type optical parts |
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2007
- 2007-09-28 WO PCT/KR2007/004765 patent/WO2009041745A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6578388B1 (en) * | 1995-08-29 | 2003-06-17 | Arroyo Optics Inc. | Grating assisted coupler devices |
| KR20000009570A (en) * | 1998-07-27 | 2000-02-15 | 이계철 | Optical fiber grating with temperature compensation |
| KR20020010903A (en) * | 1999-04-30 | 2002-02-06 | 앤더슨 데릭 제이. | Method for creating an optical structure within a photosensitive light transmissive material and of enhancing the photosensitivity of the photosensitive light transmissive material |
| KR20030053033A (en) * | 2001-12-21 | 2003-06-27 | 제이에스알 가부시끼가이샤 | Radiation Sensitive Refractive Index Changing Composition and Refractive Index Changing Method |
| JP2004029691A (en) * | 2002-05-07 | 2004-01-29 | Furukawa Electric Co Ltd:The | Fiber grating type optical parts |
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