A differential reflective intensity optical fiber angular. In the present work, an intensity modulated intrinsic fiber optic sugar sensor is presented. Fiber optic sensors have found applications in multiple industries, and their use has been gradually growing since the 1980s. Wavelength modulated fibre optic sensors among these modulation techniques, the first three modulation schemes are most commonly employed in a wide range ofapplications. Typical configuration for a twowavelength intensity modulated optical fiber sensor system.
Jan 15, 2020 our results suggest the value and applicability of intensity modulated fiber optic voltage sensors for measuring both steadystate waveforms and broadband transients which, coupled with the straightforward and compact design of the sensors, should make them effective tools in electric grid monitoring. Considerable research has been performed to develop electricallypassive fb r optic sensors of temperature, pressure, and position for aircraft control systems. Memsbased reflective intensitymodulated fiberoptic sensor. Intensitymodulated sensors were defined in chapter 2 as sensors that detect the variation of the intensity of light. In principle, the other listed optical modulation techniques are immune. Fiber optic sensors are expected to reduce the weight of these systems and to provide immunity to electromagnetic interference. Intensitymodulated fiber optic sensor for health monitoring applications. A novel sensing technique based on intensity tofrequency conversion is explained and demonstrated. Bertil arvidsson electronics design division, department of information technology and media mid sweden university, se851 70 sundsvall, sweden issn 16528948 mid sweden university licentiate thesis 35. Experimental data are presented and a comparison with a theoretical model is made. Osa multiplexing fiberoptic ultrasound sensors using laser. Fiber optic sensors have a set of properties that make them very attractive in biomechanics. Intensity modulated fiber optic sensors overview, proceedings.
Bending the fiber as the deformer closes on the fiber, radiation losses increase and the. Modeling of light intensity modulated fiber optic displacement sensors. Intensity modulated fiber optic sensors have the many distinct advantages associated with fiber optics that makes them suitable for several industrial and military. Some commercially available fiber optic sensors, though in a small way, are being used for automation in mechanical and industrial environments. Chirpedfbg cfbg based intensity modulated sensors show potential applications in various sensing areas due to their many advantages, including inherent independence of temperature, high measurement speed, and low cost, in addition to the merits of all fiber optic sensors. Since the late 1990s, the use of fiber optic sensors in the oil and gas industry has greatly expanded, especially for inwell monitoring applications 1,2. Victor giurgiutiu, in structural health monitoring of aerospace composites, 2016. Losscompensation of intensity modulating fiberoptic sensors. Although, the accuracy of the sensor is far less that for interferometric sensors, the accuracy is more than sufficient for most process control situations.
Appendix 1 gives examples of the types of modulating signals used for measurement purposes and most of these have been applied to modulate light in fibre optic sensor systems. The intensity of the light wave traveling through an optical fiber can be modified by microbending of the optical fiber, by a change in coupling of the fiber with the. In this case, the signal to be measured the measurand, intensity. Sep 26, 2002 we describe an optical measurement system based on a fiber optic sensor that detects, with 2030. Intensitymodulated fiberoptic voltage sensors for power. Oh, active acoustics control with fiber optic sensors, proceedings of spie 2002 conference on modeling, signal processing and control, vol. The shown figure gives an idea about how the light intensity work as a sensing parameter as well as how this arrangement makes the fiber to work as a vibration sensor. In this paper, a novel differential reflective intensity optical fiber angular displacement sensor was proposed.
Introduction to fiber optic sensors 7 intensity modulated fos phase modulated fos polarization modulated fos wavelength modulated fos phase modulated sensors usually use an interferometer and sense the output signal by comparing the phase of the received signal with a reference signal. Pdf transparent network for hybrid multiplexing of fiber. Among the above mentioned fibre optic sensing schemes, intensity modulation is the. Based on the operating principle or modulation and demodulation process, a fiber optic sensor can be classified as an intensity, a phase, a frequency, or a. The sensor consists of two multimode optical fibers with a spherical end, a quartz tube with dual holes, a silicon sensitive diaphragm, and a high. Optical fiber sensors intensity modulation sensors. Paper open access pressure mapping system development based. Fiber optic sensors fundamentals and applications, fourth edition, 2014 available at.
Memsbased reflective intensitymodulated fiberoptic. Pdf modeling of light intensitymodulated fiberoptic. Over the last two decades, the fiber optic technology has passed through many analytical stages. Intensity modulated sensors were defined in chapter 2 as sensors that detect the variation of the intensity of light associated with the perturbing environment. Paulo roriz et al fiber optic intensity modulated sensors. Introduction to fiber optic sensors and their types. The general concepts associated with intensity modulation include transmission, reflection, and microbending. They are also used for instrumentation and controls. An intensitymodulated optical fibre displacement sensor with. Herein, the measurand which may be dis placement or some other variable that can be transformed into displacement. There are several types of intensitymodulated sensing concepts incorporating optical fibers. The structure of the sensor probe is simple and its basic principle was first analyzed according to the intensity modulation mechanisms. Theory and applications of coupling based intensity modulated. The sensor consists of two multimode optical fibers with a spherical end, a quartz tube with dual holes, a silicon sensitive diaphragm, and a high borosilicate glass substrate hbgs.
Research article intensitymodulated fiber optic sensor for health monitoring applications. The envelope of the modulated optical signal is an analog of the modulating signal in the sense that the instantaneous power of the envelope is an. Theory and applications of coupling based intensity modulated fibre optic sensors johan jason supervisors. Intensitymodulated optical fiber sensors based on chirped. Design criteria a generalized block diagram of an intensity modulated fibreoptic sensor has been shown in fig. The intensity of the light wave traveling through an optical fiber can be modified by microbending of the optical fiber, by a change in. Throughout the late 1980s and 1990s the use of ramanbased. We propose and demonstrate the use of laser intensity modulation for the multiplexing and demultiplexing of fiber bragg gratingbased ultrasound sensors. Transparent network for hybrid multiplexing of fiber bragg gratings and intensity modulated fiber optic sensors. Fiber optic sensors which employ some type of intensity. In recent years, intensitymodulated fiberoptic sensors have attracted significant interest due to their simple system, low cost, and high dynamic response. Memsbased reflective intensitymodulated fiberoptic sensor for. Modeling of light intensitymodulated fiberoptic displacement sensors article in ieee transactions on instrumentation and measurement 604.
The highfrequency modulated optical signal serves as a carrier signal. Wavelengthmodulated fiber optic sensor for high precision. Intensity based fiber optic sensors require more light and these sensors use a multimodelarge core fibers. The relationship between fiber reflector distance and intensity of returned light example 2. Lo i among different configurations of intensity modulated fiber optic sensing systems, those with the signal and reference channels separated in the tlme. Intensity modulation an overview sciencedirect topics. Intensity modulated fiber optic strain sensor download pdf info publication number us7646946b2. In this study, we proposed a memsbased reflective intensity modulated fiber optic sensor for pressure measurement.
In 18 a pofbased intensity fiber optic sensor is reported, which is designed to monitor the human spine motions providing sensitivities around 1. Muller, smartphone technology applied in an approach for multiplexing of fibre optic intensity modulated macrobend based sensors, in 26th international conference on optical fiber sensors, osa technical digest optical society of america, 2018, paper tue82. Fibre optic intensity modulated sensors springerlink. Pdf intensitymodulated fiber optic sensor for health. The concepts for intensity modulated fiber optic sensors. Fiber optic sensor an overview sciencedirect topics.
The fiber sensor can be either an intrinsic oneif the modulation takes place directly in the fiber or extrinsic, if the modulation is performed by some external transducer as depicted in fig. Us7646946b2 intensity modulated fiber optic strain sensor. The type of these fiber sensors intensity modulated sensors were introduced in the early 60s 510. Extrinsic fiber optic sensors use an optical fiber cable, normally a multimode one, to transmit modulated light from either a non fiber optical sensor, or an electronic sensor connected to an optical transmitter. The method utilizes an intensity modulator to modulate the output power of the laser with a frequency much higher than that of the ultrasounds. The intensity of the light wave traveling through an optical fiber can be modified by microbending of the optical fiber, by a change in coupling of the fiber with the surrounding medium, or the fracture of the optical fiber. Intensity modulated fiber optic sensors have the many distinct advantages associated with fiber optics that makes them suitable for several industrial and military applications. The light source is a single mode laser whose wavelength is ramped linearly in time. Biomechanics, fiber optic sensors, intensitymodulated sensors. Phase modulation sensors and interferometric sensors. Fibre optic sensor an overview sciencedirect topics.
Memsbased reflective intensity modulated fiber optic sensor for pressure measurements article pdf available in sensors 208. In optical communications, intensity modulation im is a form of modulation in which the optical power output of a source is varied in accordance with some characteristic of the modulating signal. Intensity modulation is one of the simplest to measure because it only requires a photodetector to measure the light intensity. Request pdf modeling of light intensitymodulated fiberoptic displacement sensors lightintensitymodulated displacement sensors are currently extensively used in numerous applications. Intensity modulated fiber optic sensor for health monitoring applications. Single fiber reflective sensor light leaves the fiber end in a cone pattern, and strikes a movable reflector. Among them are those manipulating the change in light intensity coming out of the fiber as portion of the fiber is subjected to physical or chemical change. Strain measurement by using phase modulated fiber optic sensors technology diyala journal of engineering sciences, vol.
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