CN203443888U - Volatile organic compound detection device based on evanescent field of optical fiber - Google Patents
Volatile organic compound detection device based on evanescent field of optical fiber Download PDFInfo
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- CN203443888U CN203443888U CN201320422610.1U CN201320422610U CN203443888U CN 203443888 U CN203443888 U CN 203443888U CN 201320422610 U CN201320422610 U CN 201320422610U CN 203443888 U CN203443888 U CN 203443888U
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Abstract
The utility model relates to the field of organic matter detection, in particular to a volatile organic compound detection device based on an evanescent field of an optical fiber. The utility model aims to provide the volatile organic compound detection device based on the evanescent field of the optical fiber for detecting volatile organic compounds in air through direct action of the volatile organic compounds in the air and the evanescent field of the optical fiber. A tapering zone is arranged on the optical fiber, and a long-period fiber grating is arranged on the tapering zone and used as a sensitive part of gas to be detected, so that the strength of the evanescent field of the sensitive part is greatly improved, and thus the purpose of detecting the concentration of the volatile organic compounds in the gas to be detected through direct interaction of the evanescent field of the optical fiber and the gas to be detected is achieved.
Description
Technical field
The utility model relates to organic quality testing and surveys field, relates in particular to a kind of volatile organic matter pick-up unit based on optical fiber evanscent field.
Background technology
Atmospheric pollution is at present day by day serious, and wherein volatile organic matter (VOCs) is the important atmosphere pollution of a class, has toxicity, and pungency, and carcinogenicity not only can cause environmental pollution, also can grievous injury health.Volatile organic matter mainly comprises benzene homologues, organic chloride, organic ketone, alcohol, amine, ether etc., and wherein benzene homologues has been confirmed as carcinogen.1984, the volatile organic matter Jiu Bei World Health Organization (WHO) listed, and caused concern widely.The haze weather of the northern area of China was more and more serious over the past two years, country also more and more payes attention to airborne volatile organic matter pollution problem, and has put into effect relevant laws and regulations, strictly controls volatile organic matter discharge, control environmental pollution, ensures ecological safety and health.Because volatile organic matter has direct relation to the impact of health and its concentration; in a lot of fields; as chemical industry, environmental protection, medicine, food security etc.; set up sensitive quick, simple and reliable method detection volatile organic matter concentration very necessary, significant to environmental protection and safety in production.
Gas chromatography and mass spectrophotometry can be measured organic concentration, and reliable results is accurate, but exist complex operation, length consuming time, the problem such as expensive, and only appropriate experimental chamber is used, and the real-time continuous that is not suitable for operation field detects.At present, the portable volatile organic matter detector of business occurring on market is substantially all to detect principle according to photoionization, this principle can detect the volatile organic matter of extremely low concentration, but the energy that uviol lamp sends has determined that the substance classes that it can be measured is limited, the design of Weak Signal Detecting Circuit is the large difficult point of one in hardware circuit design, and price is also more expensive simultaneously.
Volatile organic matter Fibre Optical Sensor has the novel characteristics of many excellences, as little in volume, lightweight, low-loss, remote recording, distributed sensor, multichannel sensing, exempts from electromagnetic interference (EMI), on-line monitoring, environmental and durable etc., be expected to overcome the shortcoming and defect of above-mentioned volatile organic matter gas sensor, cause in recent years the increasing broad research of people and concern.According to the interaction of light and gas, volatile organic matter Fibre Optical Sensor can be divided into two classes: a class is core mode field sensing, another kind of is evanscent field sensing.For core mode field sensing, normally adopt standard traffic single-mode fiber (SMF), fiber end face is cut and put down and plate chemical-sensitive film, refraction index changing by sensitive membrane obtains different reflected signals and realizes gas sensing, but the sensitive zones of this mode is small-sized fibre core, and sensitivity is restricted.
And the cycle of long period fiber grating (LPFG) be generally tens or hundreds of micron, there is manufacture craft simple, volume is little, insertion loss is low, without features such as retroreflections, in optical communication and sensory field of optic fibre, be subject to people's attention and study, especially at sensory field.LPFG is the fibre core basic mode of symport and the coupling between each rank cladding mode.Cladding mode is the variations in refractive index sensitivity of environment to external world, and different gas and concentration can cause the change in cladding index and grating cycle, thereby cause that the resonance wavelength of LPFG and the change of amplitude realize gas sensing.But the volatile organic matter sensor of conventional single mode fiber LPFG is by the covering at optical fiber, to plate polymkeric substance sensitive thin-film material adsorbing volatilizing organic matter object outward to realize, this mode of plated film depends on the absorption of film to gas molecule, can only single specific volatile organic gas be detected, can not realize volatile organic matter total amount and detect.And because the refractive index of most of thin polymer film is greater than the refractive index of fibre cladding, the thicker resonance peak of LPFG that will cause of Thickness Ratio of film weakens even disappearance, so require the thickness of polymer film to be strict controlled in nanometer scale, require all higher to the performance of film (refractive index and thickness) and preparation condition like this.And the performance of sensor as sensitivity, detect lower limit and all need further raising.
Utility model content
The purpose of this utility model is: a kind of volatile organic matter pick-up unit based on optical fiber evanscent field is provided, realizes by allowing airborne volatile organic matter and the direct acting mode of optical fiber evanscent field detect airborne volatile organic matter.
The utility model provides a kind of volatile organic matter pick-up unit based on optical fiber evanscent field, comprising:
Single-mode fiber, be connected to wideband light source and the spectrometer at described single-mode fiber two ends;
On described single-mode fiber, have Yi Lazhui district, described La Zhui district is provided with long period fiber grating;
Described La Zhui district is fixed in an air chamber, and described air chamber is used for passing into gas to be detected;
Described spectrometer judges volatile organic matter concentration in described gas to be detected according to described wideband light source by the wavelength of described air chamber front and back and the situation of change of amplitude.
Further, described wideband light source is spontaneous radiation light source.
The utility model also provides the another kind of volatile organic matter pick-up unit based on optical fiber evanscent field, comprising:
Photonic crystal fiber, there are the first single-mode fiber and the second single-mode fiber in its two ends respectively welding;
Described the first single-mode fiber connects wideband light source, and described the second single-mode fiber connects spectrometer;
On described photonic crystal fiber, have Yi Lazhui district, described La Zhui district is provided with long period fiber grating;
Described La Zhui district is fixed in an air chamber, and described air chamber is used for passing into gas to be detected;
Described spectrometer judges the concentration of volatile organic matter in described gas to be detected by the situation of change of the wavelength before and after described air chamber and amplitude according to described wideband light source.
Further, described wideband light source is spontaneous radiation light source.
Compared with prior art, the utility model by arranging Yi Lazhui district on optical fiber, and Gai Lazhui district arranges a long period fiber grating as gas sensitization to be measured portion, greatly strengthen the evanscent field intensity of this sensitivity portion, thereby realized the object that detects volatile organic matter concentration in gas to be measured by optical fiber evanscent field and gas direct interaction to be measured.
Accompanying drawing explanation
Fig. 1: a kind of volatile organic matter pick-up unit schematic diagram based on optical fiber evanscent field that the utility model embodiment 1 provides;
Fig. 2: the volatile organic matter pick-up unit schematic diagram of the another kind that the utility model embodiment 1 provides based on optical fiber evanscent field.
Embodiment
In order to make the purpose of this utility model, technical scheme and advantage clearer, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein is only for explaining the utility model, and be not used in restriction the utility model.
Fig. 1 is a kind of volatile organic matter pick-up unit schematic diagram based on optical fiber evanscent field provided by the utility model.Shown in Fig. 1, this pick-up unit comprises: single-mode fiber 1, the wideband light source 2 that is connected to single-mode fiber 1 two ends and spectrometer 3;
On single-mode fiber 1, there are 4 ，La Zhui districts 4, Yi Lazhui district and be provided with long period fiber grating 5;
La Zhui district 4 is fixed in an air chamber 6, and air chamber 6 is for passing into gas to be detected;
One imported valve 7 and outlet valve 8 are set, for the input and output of gas to be detected on air chamber 6.
In air chamber 6, in gas to be detected, the change of the concentration of volatile organic matter can cause the resonance wavelength of long period fiber grating and the change of amplitude, can detect the concentration of volatile organic matter in gas to be detected by detecting the change of this resonance wavelength and amplitude.
Spectrometer 3 judges the concentration of volatile organic matter in gas to be detected by the wavelength of air chamber 6 front and back and the situation of change of amplitude according to wideband light source 2.
The manufacture of this pick-up unit comprises following steps:
1) by one section of single-mode fiber 1, add thermosetting one softened zone, can adopt particularly oxyhydrogen flame to heat.Oxyhydrogen flame temperature is high, fusible quartz, and can not infiltrate impurity in softening process.
2) softened zone is axially drawn to taper Cheng Yilazhui district 4 along single-mode fiber 1;
3) La Zhui district 4 arranges long period fiber grating 5, can adopt particularly femto-second laser to make long period fiber grating 5.Femto-second laser focal spot can be controlled in micron dimension, can vernier focusing.The focus of femto-second laser is accurately navigated to fiber core, and fiber core produces non-linear absorption at focus area to laser, makes absorption region density of material become large, thereby makes refractive index become large.Along the axial pointwise of fiber core, fiber core is carried out to femtosecond laser index modulation and just can form long period fiber grating.
4) Jiang Lazhui district 4 is fixed in an air chamber 6, particularly, can be fixed on half-cylindrical quartz base plate by ultraviolet glue.Ultraviolet glue can not produce other volatile ingredients the gas componant to be detected in air chamber 6 is exerted an influence.
5) two ends of single-mode fiber 1 are connected respectively to wideband light source 2 and spectrometer 3, particularly, wideband light source 2 can adopt spontaneous radiation light source.
Fig. 2 is the volatile organic matter pick-up unit schematic diagram of another kind provided by the utility model based on optical fiber evanscent field.Shown in Fig. 1, this pick-up unit comprises: photonic crystal fiber 9, and there are the first single-mode fiber 10 and the second single-mode fiber 11 in the two ends of photonic crystal fiber 9 respectively welding;
The first single-mode fiber 10 connects wideband light source 2, the second single-mode fibers 11 and connects spectrometer 3;
On photonic crystal fiber 9, there are 4 ，La Zhui districts 4, Yi Lazhui district and be provided with long period fiber grating 5;
La Zhui district 4 is fixed in an air chamber 6, and air chamber 6 is for passing into gas to be detected;
One imported valve 7 and outlet valve 8 are set, for the input and output of gas to be detected on air chamber 6.
In air chamber 6, in gas to be detected, the change of the concentration of volatile organic matter can cause the resonance wavelength of long period fiber grating and the change of amplitude, can detect the concentration of volatile organic matter in gas to be detected by detecting the change of this resonance wavelength and amplitude.
Spectrometer 3 judges the concentration of volatile organic matter in gas to be detected by the wavelength of air chamber 6 front and back and the situation of change of amplitude according to wideband light source 2.
The manufacture of this pick-up unit comprises following steps:
1) by one section of photonic crystal fiber 9, add thermosetting one softened zone, can adopt particularly oxyhydrogen flame to heat.Oxyhydrogen flame temperature is high, fusible quartz, and can not infiltrate impurity in softening process.
2) softened zone is axially drawn to taper Cheng Yilazhui district 4 along photonic crystal fiber 9;
3) La Zhui district 4 arranges long period fiber grating 5, can adopt particularly femto-second laser to make long period fiber grating.Femto-second laser focal spot can be controlled in micron dimension, can vernier focusing.The focus of femto-second laser is accurately navigated to fiber core, and fiber core produces non-linear absorption at focus area to laser, makes absorption region density of material become large, thereby makes refractive index become large.Along the axial pointwise of fiber core, fiber core is carried out to femtosecond laser index modulation and just can form long period fiber grating.
4) the first single-mode fiber 10 and the second single-mode fiber 11 are distinguished to weldings at the two ends of photonic crystal fiber 9;
5) Jiang Lazhui district 4 is fixed in an air chamber 6.Particularly, can be fixed on half-cylindrical quartz base plate by ultraviolet glue.Ultraviolet glue can not produce other volatile ingredients the gas componant to be detected in air chamber 6 is exerted an influence.
6) the first single-mode fiber 10 and the second single-mode fiber 11 are connected respectively to a wideband light source 2 and a spectrometer 3.Particularly, wideband light source 2 can adopt spontaneous radiation light source.
The utility model is usingd optical fiber itself as responsive portion, usings and draws cone and LPFG as the effective means that excites evanscent field, does not need to plate any extra chemical-sensitive film, has realized highly sensitive volatile organic matter gas gross and has detected.
The foregoing is only preferred embodiment of the present utility model; not in order to limit the utility model; all any modifications of doing within spirit of the present utility model and principle, be equal to and replace and improvement etc., within all should being included in protection domain of the present utility model.
Claims (4)
1. the volatile organic matter pick-up unit based on optical fiber evanscent field, is characterized in that, comprising:
Single-mode fiber, be connected to wideband light source and the spectrometer at described single-mode fiber two ends;
On described single-mode fiber, have Yi Lazhui district, described La Zhui district is provided with long period fiber grating;
Described La Zhui district is fixed in an air chamber, and described air chamber is used for passing into gas to be detected;
Described spectrometer judges volatile organic matter concentration in described gas to be detected according to described wideband light source by the wavelength of described air chamber front and back and the situation of change of amplitude.
2. the volatile organic matter pick-up unit based on optical fiber evanscent field as claimed in claim 1, is characterized in that, described wideband light source is spontaneous radiation light source.
3. the volatile organic matter pick-up unit based on optical fiber evanscent field, is characterized in that, comprising:
Photonic crystal fiber, there are the first single-mode fiber and the second single-mode fiber in its two ends respectively welding;
Described the first single-mode fiber connects wideband light source, and described the second single-mode fiber connects spectrometer;
On described photonic crystal fiber, have Yi Lazhui district, described La Zhui district is provided with long period fiber grating;
Described La Zhui district is fixed in an air chamber, and described air chamber is used for passing into gas to be detected;
Described spectrometer judges the concentration of volatile organic matter in described gas to be detected by the situation of change of the wavelength before and after described air chamber and amplitude according to described wideband light source.
4. the volatile organic matter pick-up unit based on optical fiber evanscent field as claimed in claim 3, is characterized in that, described wideband light source is spontaneous radiation light source.
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| CN201320422610.1U CN203443888U (en) | 2013-07-16 | 2013-07-16 | Volatile organic compound detection device based on evanescent field of optical fiber |
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| CN201320422610.1U CN203443888U (en) | 2013-07-16 | 2013-07-16 | Volatile organic compound detection device based on evanescent field of optical fiber |
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Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439262A (en) * | 2013-07-16 | 2013-12-11 | 深圳大学 | Volatile organic compound detection device based on optical fiber evanescent field and manufacturing method thereof |
| CN105203462A (en) * | 2015-09-25 | 2015-12-30 | 中国工程物理研究院激光聚变研究中心 | Oxygen monitoring device and monitoring method thereof |
| CN105445224A (en) * | 2014-06-06 | 2016-03-30 | 纳米及先进材料研发院有限公司 | Reusable long period microfiber grating for detection of dna hybridization |
| CN113640475A (en) * | 2021-09-16 | 2021-11-12 | 朱远贵 | Fertilizer detection device |
| CN114966985A (en) * | 2022-06-01 | 2022-08-30 | 暨南大学 | Optical fiber humidity sensor and manufacturing method thereof |
-
2013
- 2013-07-16 CN CN201320422610.1U patent/CN203443888U/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103439262A (en) * | 2013-07-16 | 2013-12-11 | 深圳大学 | Volatile organic compound detection device based on optical fiber evanescent field and manufacturing method thereof |
| CN105445224A (en) * | 2014-06-06 | 2016-03-30 | 纳米及先进材料研发院有限公司 | Reusable long period microfiber grating for detection of dna hybridization |
| CN105203462A (en) * | 2015-09-25 | 2015-12-30 | 中国工程物理研究院激光聚变研究中心 | Oxygen monitoring device and monitoring method thereof |
| CN113640475A (en) * | 2021-09-16 | 2021-11-12 | 朱远贵 | Fertilizer detection device |
| CN114966985A (en) * | 2022-06-01 | 2022-08-30 | 暨南大学 | Optical fiber humidity sensor and manufacturing method thereof |
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| C14 | Grant of patent or utility model | ||
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| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140219 Termination date: 20140716 |
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