Increase in the numerical aperture of the fiber increases the sensitivity of the sensor in the case of both the probes. Nucleic acid functionalized evanescent wave fiber optic ewfo biosensors have attracted much attention due to their remarkable advantages in both device configuration and sensing performance. Evanescent wave absorption based fiberoptic sensor. An optical fiber deformed as a micropipette is employed to force the evanescent wave to interact with its environment. The easiest configuration of this sensor is shown on figure 3b, where the protective plastic jacket of the fiber. A general theory for fiberoptic, evanescentwave spectroscopy and sensors is presented for straight, uncladded, stepindex, multimode fibers. A simple theory for interpreting these results has been developed. We investigate the behavior of a permanently microbent fiber optic sensor when it is immersed in an absorbing medium. The results pointed out the sensitivity of the sensor. Evaluation of an evanescent fiber optic chemical sensor. Mbs transmission 1985 1st industrial applications and military systems advent of single mode systems. The evanescent wave from an optical fiber can be used in a gas sensor, and evanescent waves figure in the infrared spectroscopy technique known as attenuated total reflectance. Phoenix photonics fiber evanescent field technology technical briefing phoenix photonics 2003 evanescent field v1.
A comparative experimental study of the fiber optic evanescent field absorption sensor based on straight and ushaped probes is presented. The sensor, composed of a lead salt tunable infrared laser and a multimode uncladded silver halide infrared optic fiber, was used for rapid measurement of sulfur hexafluoride pressures at a fewpercent detection limit. Fiber optic intensity sensors based on the interaction between an external medium and t he evanescent wave of unclad and tapered multimode and single mode fibers have been developed to measure. High sensitivity is achieved by launching the selected rays into the fiber. The main feature of fiber tapers is the fact that they can strongly enhance the power fraction in the cladding in the form of evanescent wave increasing the sensitivity to environmental changes. High sensitivity is achieved by launching the selected rays into the fiber having tapered sensing regions.
Pdf theoretical analysis of fiberoptic evanescent wave. The model includes various launching conditions, input and output endface fresnel transmission losses, multiple fresnel reflections, bulk absorption, and evanescent wave. Since salmonella is most commonly associated with poultry products, an evanescent wave fiber optic assay was developed to detect salmonella in shell egg and chicken breast and data were compared with a time. The effects of numerical aperture and the core radius of the fiber on the sensitivity of the sensor are experimentally investigated. To say it simply, the higher vs value is, the deeper the penetration in the evanescent field is. Temperatureindependent polymer optical fiber evanescent. To test silica optical fibers as evanescent wave sensors the procedures described below for fiber preparation and performing adsorption experiments were followed. In general, the penetration depth of an optical fiber, stripped. The work herein contained describes the fabrication of three types of sensors. Stripped fiber optic evanescent wave sensors provided a convenient and versatile sensing platform, and have been used to detect a variety of chemical and biological substances 56. Specifically, efocs can use commercially available plastic clad silica, pcs, fiber optic cables as the optical waveguide element. Recent advances in fiberoptic evanescent wave sensors for. In electrical engineering, evanescent waves are found in the nearfield region within one third of a wavelength of any radio antenna. The sensor is fabricated by partial removal of the cladding material surrounding the core of a multimode fiber optic.
Gas sensing using evanescent waves of optical fibers is investigated. Nearultraviolet evanescentwave absorption sensor based on a. Fiber optic based evanescent wave sensor for the detection of. Perfluorinated plastic optical fiber tapers for evanescent. Ache kernforschungszentrum karlsruhe, institut fur radiochemie, postfaeh 3640, d7500 karlsruhe 1, germany a fiber optic evanescent field absorbance sensor. Fiber optic intensity sensors based on the interaction between an external medium and t he evanescent wave of unclad and tapered multimode and single mode fibers have been. Our small footprint couplers, splittercombiners and other components can be configured as nxm port, splice free coupler arrays and as custom assemblies fabricated for high er and low loss. Fiberoptic evanescent wave spectroscopy in the middle infrared. Evanescent wave opticalfiber sensing temperature, relative. The nanofiber optic evanescent field sensor based on a changed cladding part as a sensor presented numerically. Optical and quantum electronics 27 1995 747753 a novel probe for an evanescent wave fibre optic absorption sensor b.
A fiber optic ph sensor based on evanescent wave absorption is presented. First results in the preparation and analysis of an optical fiber with a novel geometry which facilitates the access of chemical species to the evanescent field for sensing purposes are presented. Splicefree pm coupler trees and assemblies are available in custom configurations having very low backreflection and insertion loss other fiber devices, such as the 968p polarization splitter andor 915b916b piezo fiber stretchers, can be integrated with coupler arrays to form advanced communications systems and fiber. Salmonella enterica is a major foodborne pathogen of worldwide concern. The waveguide modes of the segmented structure are. Development of fibre optic evanescentwave fluorescence. This system provides a physical basis for fiber optic fluoroimmunoassay independent of immunochemical binding and kinetics. Fiber optic sensors fundamentals and applications, fourth edition, 2014 available at.
Fiber optic biosensors are one of the most widely studied for rapid detection of many pathogens, toxins, proteins, and hormones 1416. Sensitive and rapid detection methods to assess product safety before retail distribution are highly desirable. Nanooptical fiber evanescent field sensors scientific. Waveguide evanescent field absorption has been measured as a function of cladding refractive index and bulk absorption coefficient. Fiber optic nearultraviolet evanescent wave sensors have been constructed, and their feasibility for practical applications has been demonstrated. Highprecision detection and identification of a large variety of gases are possible. Evaluation of an evanescent fiber optic chemical sensor for. Optical fiber humidity sensor based on evanescent wave scattering pages in study. A segmented structure optic fiber sensor is proposed and demonstrated. We investigate the behavior of a permanently microbent fiber optic sensor when it is immersed in an absorbing. A single fiber is used as both a sensor and an optical transmission line. Two distinct detection schemes, namely, brightfield and darkfield detection configuration, are employed for the measurements.
Analytical and bioanalytical chemistry 2010, 396 2, 943948. Osa fiberoptic evanescent wave sensor with a segmented. In general, the penetration depth of an optical fiber, stripped off its. We believe that this method can be used for onsite routine monitoring and screening. Saaski, michael bizak, and jennifer yeatts multimode evanescent wave based sensors. Optical fiber with novel geometry for evanescentwave sensing. Principles with the development of optical bers that are transparent in the mir it was realized that segments of these bers may serve as atr elements. A coiled fiber optic chemical sensor has proven to be effective for the remote detection of volatile organic compounds, such as trichloroethylene tce, 1,1dichloroethylene dce, and gasoline, in aqueous solutions. Osa fiberoptic evanescentwave methanegas sensor using. Development of fibre optic evanescentwave fluorescencebased. The degree of variation with respect to the temperature is. Resins using an evanescent wave highindex fiberoptic sensor joy p. The objective of this thesis will be to present an analytical model developed for a multimode fiber optic evanescent wave sensor foews capable of monitoring the charge cycle of a lithiumion battery cell.
The sensors, used for the detection of ozone near the 254nm peak of the hartley absorption band, were fabricated from coiled segments of lowcost multimode plasticclad silica optical fibers. Sensors based on this principal, known as evanescent fiber optic chemical sensors, efocs, or fiber optic evanescent wave sensors, fews, hold promise for use in environmental applications. Absorbance has been directly measured in evanescent wave fiber optic chemical sensors buerck et al. In all optical fibers, light propagates by means of total internal reflection, wherein the propagating light is launched into waveguide at angles such that upon reaching the claddingcore interface, the energy is reflected and remains in the core. One critical technique in ewfo biosensor fabrication is its surface modification, which requires 1 minimal nonspecific adsorption and 2 highquality.
Pdf a novel probe for an evanescent wave fibreoptic. Fiber optic evanescent wave chromium sensor request pdf. Infrared transparent optical fibers as evanescent wave sensors. Lowcost wavelengthselective evanescent fiber optic. The sensor, composed of a lead salt tunable infrared laser and a multimode uncladded silver halide infrared optic fiber, was used. On power transfer from corecladding interface to fiber endface. Pdf fiber optic intensity sensors based on the interaction between an external medium and t he evanescent wave of unclad and tapered multimode and. The sensing dye, methylene blue, was immobilized in the substitutional cladding using solgel process. The model includes various launching conditions, input and output endface fresnel transmission losses, multiple fresnel reflections, bulk absorption, and evanescentwave. Fiber optic evanescent wave foew sensors are promising in pollutant detection and evaluation of water quality because of their high resistance to corrosion, smart structure, antielectromagnetic interference, and low cost. The amount of rays guided along the fiber probe is the result of the absorption of evanescent waves produced at the corecladding interface.
Evanescent wave fiber optic biosensors sciencedirect. Characterization of a fiberoptic evanescent wave absorbance sensor for nonpolar organic compounds j. Cure monitoring of the liquid composite molding process. Another type ofevanescent wave fibre sensor was based on excitation and detection of fluorescence using evanescent waves. A molecularly imprinted polymerbased evanescent wave fiber. A novel fiber optic evanescent wave sensor is presented. Fiberoptic evanescent wave spectroscopy in the middle. A molecularly imprinted polymerbased evanescent wave.
The analyte diffuses into the hydrophobic cladding and evanescent wave. Nucleic acid functionalized fiber optic probes for sensing in evanescent wave. The multimode fiber is removed of its cladding and with a combination of heat and tension a reduction in the diameter is achieved to force the evanescent wave to increase its power. Fourier transform nearinfrared monitoring of reacting resins. We systematically investigate the wavelength dependence of this sensor during the measurement of the temperature. We report here a lowcost evanescent field wave fiber optic temperature sensor. Pacific northwest fiber optic sensor workshop, 1995, troutdale, or, united states. Based on the evanescent wave couplers 954p fixed ratio and 905p variable ratio, polished fibers are coated with polarization sensitive layers before assembly. Microbent optical fibers are potential candidates for evanescent wave sensing. An economical optical fiber sensor has been developed with a refractive index greater than 1. Optical fiber evanescent wave sensor for oxygen deficiency. Fiber optic tapers are important devices that can act as sensors and couplers. However, the number of parameters measured using evanescent wave fiber optic sensors is much more limited.
Two basic versions of experimental setups were developed for ber optic evanescent wave spectroscopy. Characterization of a fiberoptic evanescent wave absorbance. A threedimensional model is formulated within the framework of geometric optics. Nucleic acid functionalized fiber optic probes for sensing. Mcdonough polymers division, national institute of standards and technology, quince orchard and clopper roads, gaithersburg, maryland 20899 in this work, a highindex silicabased beroptic minibundle sen.
Development of an analytical model for a fiber optic. Theory of fiberoptic, evanescentwave spectroscopy and sensors. Methane gas is detected by means of its strong optical absorption of the 3. A large penetration depth of an evanescent wave is the key to success for developing a fiberoptic evanescentwave sensors. The launching condition and the geometry of the sensing region are found to be the main parameters that can influence the sensitivity of the sensor. Theory of fiberoptic, evanescentwave spectroscopy and. Nucleic acid functionalized fiber optic probes for sensing in.
Specifically, efocs can use commercially available plastic clad silica, pcs, fiber optic cables as the optical. Xiyu zhu a, ruoyu wang a, kaidong xia ab, xiaohong zhou a and hanchang shi a a state key joint laboratory of espc, research centre of environmental and health sensing technology, center for sensor technology of environment and health, school of environment, tsinghua. Pdf theory of fiberoptic, evanescentwave spectroscopy. A promising answer to such demands seems to be fiber optic chemical sensor systems focs. Microbent optical fibers as evanescent wave sensors. Osa temperature effects on a fiberoptic evanescent wave. A comprehensive work has been performed both theoretically and experimentally using a geometrical modification approach to improve the sensors. Optical characteristics of fiber optic evanescent wave sensors.
Our small footprint couplers, splittercombiners and other. Theory of fiberoptic, evanescentwave spectroscopy and sensors article pdf available in applied optics 35. We have designed and developed an optical fiber based evanescent sensor for oxygen deficiency detection. Xiyu zhu a, ruoyu wang a, kaidong xia ab, xiaohong zhou a and hanchang shi a a state key joint laboratory of espc, research centre of environmental and health sensing technology, center for sensor. Oct 31, 2015 an evanescent wave fiber optic sensor, based on a mip as recognition element. A typical fiber optic sensor operates by using a laserdiode to generate an evanescent wave along an optical. Evanescent wave opticalfiber sensing temperature, relative humidity, and ph sensors ainhoa gaston, ibon lozano, fatima perez, fernando auza, and joaquin sevilla abstract sensitive and versatile evanescent wavesensing systems featuring polished optical fiberbased sensor designs with lowcost light sources have been developed for. Smallvolume fiber optic evanescent wave absorption sensor for nitrite determination. To prepare the probe a small length of the cladding is removed from the middle portion of the fiber.
The basic principle is to link a specific polyclonal or monoclonal antibody, that binds to a target analyte, to the core of the fiber optic waveguide. Fiber evanescent field technology fiber optic products from. Evanescent wave fiber optic biosensors are a subset of fiber optic biosensors that perform the sensing function along the fiber s cylindrical length. Evanescent wave fiber optic biosensor for salmonella. A typical fiber optic sensor operates by using a laserdiode to generate an evanescent wave along an optical waveguide to activate a fluorophore for detection. Fiber evanescent field technology fiber optic products. Osa fiberoptic evanescent wave sensor for gas detection. The excitation of fluorescein by evanescent wave interaction and subsequent detection of fluorescence from the optical fiber. Temperatureindependent polymer optical fiber evanescent wave sensor article pdf available in scientific reports 5.
Sensitive and versatile evanescent wave sensing systems featuring polished optical fiber based sensor designs with lowcost light sources have been developed for temperature, relative humidity, and ph measurements. An evanescent wave fiber optic sensor, based on a mip as recognition element. This is the basis of the fiber optics evanescent wave sensor. Evanescent field component groups three broad groups of component type can be defi ned. A novel fiberoptic evanescent wave sensor is presented. The evanescent wave which extends from the fiber optic core has a penetration depth given by 11.
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