Conference proceedings papers presentations journals. Fiber laser, michaelson interferometer, and coherence length. Advanced photonics journal of applied remote sensing. In this work, thincore fiber machzehnder interferometer deposited. Fiber taperbased machzehnder interferometer for ethanol concentration measurement changrui liao 1,2. Generally, multiwavelength fiber laser based on a standard machzehnder mz interferometer is nontunable 4 except incorporating an optical variable delay line ovdl to change the path difference between two interferometer arms 5.
Distributed optical fiber dynamic magnetic field sensor based on magnetostriction. Fiber machzehnder interferometer mzi is a type of useful sensing con. In this study, two kinds of tapered fiber machzehnder interferometer, either. When cladding mode coupling into fiber core of single mode optical fiber and interfering with core mode, which is known as the optical fiber internal mach zehnder interference, such as thincore. The attenuation peak wavelength of the interference with speci.
A machzehnder interferometer with two abrupt single mode fiber tapers is simulated, constructed, and demonstrated. Micronanofibers mnfs are optical fibers with diameters close to or below the wavelength of the guided light. This s fiber taper mzi has a refractive index ri sensitivity of 1590 nmrefractive index unit in the ri range of 1. By introducing two notches along the fiber axis in a normal single. Modal interferometer based on a cshaped ultrathin fiber.
Some fiber structures such as the inline fiber mach zehnder interferometer mzi 7, dualcavity fiber fabryperot interferometer fpfi 8, and twomode fiber interferometric probe 9 are investigated for simultaneous measurement of ri and temperature, however, these sensors require special fibers which bring relatively high insertion loss. By fusion splicing a standard telecommunication single mode fiber smf28. Yang, employing higher order cladding modes of fiber bragg grating for analysis of refractive index change in volume and at the surface, ieee photonics journal, accepted. The ultrathin fiber taper fabricated by adiabatically stretching a heated single mode optical fiber smf is made in a cshape bent to form a modal. The first photonic crystal module includes a first substrate and a plurality of first photonic crystals, disposed on the first substrate and are arranged in a matrix. Thus, only the fiber optic interferometric sensors are treated. Nov 01, 2014 novel fabrication of an inline machzehnder interferometer mzi via tapering of perfluorinated gradedindex plastic optical fiber pof. A fiber optic interferometer uses the interference between two beams that have propagated through different optical paths of a single fiber or two different fibers. Interferometry is a family of techniques in which waves, usually electromagnetic waves, are superimposed, causing the phenomenon of interference, which is used to extract information. The ri sensitivity of the twotaper mzi is nearly comparable to that of the steplike taper mzi in this work, however, the insertion loss of the twotaper mzi is much larger. In this paper, a novel inline modal interferometer for refractive index ri sensing is proposed and experimentally fabricated by cascading single taper and multimodedouble claddingmultimode mdm fiber structure. Single stapered fiber machzehnder interferometers rui yang,1 yongsen yu,1,3 yang xue,1 chao chen,1 qidai chen,1 and hongbo sun1,2,4 1state key laboratory on integrated optoelectronics, college of electronic science and engineering.
We report a compact fiber inline machzehnder interferometer for refractive index sensing with high sensitivity and precise sensing location. Nanopatterned evanescentfield fiberoptic interferometer. A micro displacement sensor includes a first photonic crystal module, a second photonic crystal module, a light source and a detector. The michelson interferometer performs very stable, longterm static measurements, while the machzehnder interferometer performs extremely sensitive shortterm dynamic measurements. We introduced a nanopatterned fiber optic interferometer foi based on an optical fiber line embedded with a short capillary which excites the evanescent field by total reflection of light in the wall waveguide interacting with the fluid and causing the optical signal change. A taperbased machzehnder interferometer mzi embedded in a thinned optical. These interferometers are driven by our own pz1 lowprofile fiber stretcher with enhanced modulation, through a front. For instance, a single mode fiber mzi consisting of two.
A single mode fiber optic machzehnder interferometric strain sensor has been developed which uses many turns of single mode optical fibers in the sensing arm to amplify the effects of earth strain. Ultraabrupt tapered fiber machzehnder interferometer. Interferometry is an important investigative technique in the fields of astronomy, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy and its applications to. Infiber machzehnder interferometric refractive index. Ammonia is an important indicator among environmental monitoring parameters. An inline machzehnder interferometer using thincore fiber. Tapered fibres allow access to the evanescent wave of the propagating mode, which can be exploited to facilitate chemical sensing by. The humidity and the temperature were measured over the ranges from.
By fusionsplicing, the taper diameterlength ratio is 1. Tunable and switchable multiwavelength erbiumdoped fiber. Fiber inline machzehnder interferometer fabricated by. Recently, optical fiber machzehnder interferometer. A miniaturized single fiber inline machzehnder interferometer is proposed for hightemperature sensing. A coreoffset mach zehnder interferometer based on a non. Refractive index measurement with optical fiber mach. Improved vibration sensor based on a biconical tapered. Osa temperature effects of machzehnder interferometer. A novel method for simultaneous measurement of refractive index and temperature based on a small core and cladding diameters thinned fiber machzehnder interferometer mzi using singlemodemultimodethinnedmultimodesinglemode smtms fiber structure is proposed. One of the areas of fiber optic sensors with greatest research interest has been in the.
The protein sensing device exhibited an ri sensitivity of about 1500 nmriu in the limited ri range of 1. Fiber interferometers optiphase, a leading supplier of ultrahigh performance interferometric systems, offers fiber interferometers for use in precision test and measurement instrumentation as well as fiber sensing systems. Inline tapered fiber machzehnder interferometer for biosensing. To interrogate this sensing device, coherence addressing and pseudoheterodyne processing were used. Dual exponential polynomials and linear differential equations. Also, a number of implementations, such as gradiometers and push. A fiber inline machzehnder interferometer mzi consisting of ultraabrupt fiber tapers was fabricated through a new fusionsplicing method. Asymmetrical infiber machzehnder interferometer for. Quantifying loss in minimisation single mode fiber tapers. The typical feature size of the structure has a length of 660.
Infiber machzehnder interferometer for gas refractive index. Single stapered fiber machzehnder interferometers osa. The development of reliable, affordable and efficient sensors is a key step in providing tools for efficient monitoring of critical environmental parameters. In this paper, an optical fiber sensor consisting of a machzehnder interferometer mzi cascaded with a fiber bragg grating fbg is proposed and experimentally demonstrated. Recently the stapered fiber interferometer has attracted growing research interest and a good variety of stapered fiber sensors have been developed for the measurement of different physical or chemical parameters such as temperature 29. The interferometer has a microcavity in one of its arms, formed by removing part of the. By fusionsplicing, the taper diameterlength ratio is around 1. Temperature effects of mach zehnder interferometer using a liquid crystalfilled fiber boyan ho,1 hsienpin 2su,1 1,3,yupei tseng, shintson wu,3 and shugjune hwang 1department of electrooptical engineering, national united university, maioli, 360, taiwan. Tsaiultraabrupt tapered fiber machzehnder interferometer sensors. With the rapid advancement in microtechnology, microstructured fiber sensors have benefitted from the trends of possessing high performance, versatilities and spatial miniaturization. The problem of polarization fading is discussed, and various approaches to overcome this problem are listed. The mzi consists of two novel trapezoid cone structures and a length of single mode fiber smf. A machzehnder interferometer mzi based fiberoptic refractive index ri sensor is constructed by uniformly tapering standard single mode fiber smf for ri.
This mzi shows interference fringes that are sufficiently sharp for usage as refractive index ri and strain sensors. Pdf tapered fiber machzehnder interferometer for simultaneous. In physics, the machzehnder interferometer is a device used to determine the relative phase shift variations between two collimated beams derived by splitting light from a single source. A dual tapered machzehnder interferometer for magnetic. Intensitymodulated abrupt tapered fiber machzehnder interferometer for the simultaneous sensing of temperature and curvature. Ultraabrupt tapered fiber machzehnder interferometer sensors benye li 1, lan jiang 1,2. Index sensing with machzehnder interferometer based on concatenating two single mode fiber tapers, ieee photonics technol. In this work, an lpgbased machzehnder modal interferometer with a tapered fiber section between the two lpgs is studied as a sensing structure for measuring environmental refractive index. Transmission spectral response regarding the spectrum shift and transmission loss variation of the proposed sensor has been characterized and the experimental. Osa single stapered fiber machzehnder interferometers. One arm of the interferometer contains a microcavity formed by removing part of the fiber core near the core and cladding interface by femtosecond laser micromachining, and the other arm remains in line with the remaining part of the fiber core. An inline machzehnder interferometer using thincore. Optimization of cascaded fiber tapered mach zehnder interferometer and refractive index sensing technology.
A michelson interferometer, as invented by albert abraham michelson, uses a single beam splitter for separating and recombining the beams. Refractive index and strain sensing using inline machzehnder. The bandwidth of the signal determines its coherence length, which is the difference in path length that a laser signal can interfere with itself. The advantages and applications of the machzehnder. Vibration sensing using a tapered bendinsensitive fiber. The sensor based on the machzehnder interferometer has, in general, two outputs instead of the mirrors and the light signal is decoded at outputs by a photo detector.
Temperature effects of machzehnder interferometer using a. Singlephoton transistor using a forster resonance daniel tiarks, simon baur, katharina schneider, stephan durr, and gerhard rempe phys. The mzi was implemented by coreoffset fusion splicing one section of a nzdsf fiber between two pieces of single mode fibers smfs. Optical machzehnder interferometers mzis are useful components in a variety of optical applications, including optical modulation. This s fiber taper mzi has a refractive index ri sensitivity of 1590 nmrefractive index. Intensitymodulated abrupt tapered fiber machzehnder.
The machzehnder interferometer is a simple highly configurable device used to demonstrate interference by division of amplitude. Pdf an approach to achieve simultaneous measurement of refractive index and temperature is. We introduce here a novel, assemblyfree allin fiber core mzi, which is directly written with a femtosecond laser. An approach to achieve simultaneous measurement of refractive index and temperature is proposed by using a machzehnder interferometer realized on tapered single mode optical fiber. Tapered fiberoptic machzehnder interferometer for ultra. Effect of fiber tapering in lpgbased machzehnder modal. The curvature sensor structure based on a machzehnder interferometer mzi usually involves two fiber optic modecoupling sections, where the two sections work as a beam splitter and a beam combiner. Tapered fiber machzehnder interferometer for simultaneous. Ultracompact allinfibercore machzehnder interferometer. Spectrum onlinetunable machzehnder interferometer based on. Fiber taperbased machzehnder interferometer for ethanol. The apparatus consists of two independent interferometers. Andrews, rachel ross, dorit munzke, camiel van hoorn, andrew brzezinski, jack a. The interferometer has an insertion loss of 5 db and an extinction ratio over 15 db.
A fiber mach zehnder interferometer mzi sensor, novel to our knowledge, based on a single s like fiber taper has been fabricated via applying nonaxial pull in fiber tapering by a fusion splicer. Owing to evanescent field in taper area, the ultrasensitive and linear intensityresponses to the varied surrounding ri are gained in both single and doublepass structures. Sensors free fulltext tapered optical fibre sensors. The performance comparison of the proposed mzi with other single mode fiber machzehnder interferometers smfmzis has been listed in table 2. Design and fabrication of a heterostructured cladding. A fiber machzehnder interferometer mzi sensor, novel to our knowledge, based on a single slike fiber taper has been fabricated via applying nonaxial pull in fiber tapering by a fusion splicer. Refractive index sensing with machzehnder interferometer based on concatenating two single mode fiber tapers.
Osa fiber inline machzehnder interferometer fabricated. Tapered fiberoptic machzehnder interferometer for ultrahigh. Mzi sensors based on tapered structures have attracted lots of interest in various physical and chemical. High sensitivity of taperbased machzehnder interferometer. Singlemode fiber machzehnder interferometer as an earth. The interferometer has been used, among other things, to measure phase shifts between the two beams caused by a sample or a change in length of one of the paths. The transmission spectra of the proposed mzi with different lcinfiltrated length were measured and the temperature. By fusionsplicing, the taper diameterlength ratio is. In this study, a novel fiber optic sensor consisting of a tapered bendinsensitive fiber based machzehnder interferometer is presented to realize damped and continuous vibration measurement. We demonstrated a simple and costeffective method to fabricate all fiber machzehnder interferometer mzi based on cascading a short section of liquid crystal lcfilled hollowoptic fiber hof between two single mode fibers by using automatically splicing technique. Magnetic field sensor based on nonadiabatic tapered optical.
Pdf a fiber machzehnder interferometer mzi sensor, novel to our knowledge, based on a single slike fiber taper has been fabricated via applying. Recent developments in microstructured fiber optic sensors. Zehnder interferometer in a singlemode fiber and its applications in biosensing. By introducing a positive refractive indexmodified zone in half of the fiber. Laser coherence length fiber lasers produce a thz frequency with a finite bandwidth, which depends on the nature and construction of the laser itself, as well as the physics of the oscillation mechanism. In fiber mach zehnder interferometer for gas refractive index measurements based on a hollowcore photonic crystal fiber nicholas l. Sensors free fulltext ultrasensitive fiber refractive. Optimization of cascaded fiber tapered machzehnder. The chapter provides various interferometer configurations. Hightemperature sensing using miniaturized fiber inline. Effect of bending and orientation on the fiber modal mach. Fiber inline machzehnder interferometer fabricated by femtosecond laser micromachining for refractive index measurement with high sensitivity ying wang,1,2 minwei yang,1 d.
Tapered fiber optic machzehnder interferometer for ultrahigh sensitivity measurement of refractive index. The double cladding structure and the central coating region of the in fiber interferometer ensure an enhanced mechanical strength, reduced external disturbance, and a more uniform spectrum. A twofrequency michelson interferometer is used to measure the liquid sample displacement in the air, while an optical fiber machzehnder interferometer measures the optical path length difference in the moving sample. If the two mirrors are aligned for exact perpendicular incidence see the upper figure, only one output is accessible, and the light of the other output goes back to the light source. These tiny fibers can offer engineerable waveguiding properties including optical confinement, fractional evanescent fields, and surface intensity, which is very attractive to optical sensing on the micronano scale. Machzehnder interferometer an overview sciencedirect. Pdf single stapered fiber machzehnder interferometers. A machzehnder interferometer mzi based fiberoptic refractive index ri sensor is constructed by uniformly tapering standard single mode. Ultraabrupt tapered fiber machzehnder interferometer sensors.
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