Interferometric Fiber Optic Sensors
23 Feb 2012-Sensors (Multidisciplinary Digital Publishing Institute (MDPI))-Vol. 12, Iss: 3, pp 2467-2486
TL;DR: Each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields and some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications.
Abstract: Fiber optic interferometers to sense various physical parameters including temperature, strain, pressure, and refractive index have been widely investigated. They can be categorized into four types: Fabry-Perot, Mach-Zehnder, Michelson, and Sagnac. In this paper, each type of interferometric sensor is reviewed in terms of operating principles, fabrication methods, and application fields. Some specific examples of recently reported interferometeric sensor technologies are presented in detail to show their large potential in practical applications. Some of the simple to fabricate but exceedingly effective Fabry-Perot interferometers, implemented in both extrinsic and intrinsic structures, are discussed. Also, a wide variety of Mach-Zehnder and Michelson interferometric sensors based on photonic crystal fibers are introduced along with their remarkable sensing performances. Finally, the simultaneous multi-parameter sensing capability of a pair of long period fiber grating (LPG) is presented in two types of structures; one is the Mach-Zehnder interferometer formed in a double cladding fiber and the other is the highly sensitive Sagnac interferometer cascaded with an LPG pair.
Citations
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TL;DR: A diaphragm-free fiber-optic Fabry-Perot interferometric gas pressure sensor is designed and experimentally verified to improve the accuracy of the pressure sensor in high temperature environments and has less than 1.5% non-linearity at different temperatures by using temperature decoupling method.
Abstract: A diaphragm-free fiber-optic Fabry-Perot (FP) interferometric gas pressure sensor is designed and experimentally verified in this paper. The FP cavity was fabricated by inserting a well-cut fiber Bragg grating (FBG) and hollow silica tube (HST) from both sides into a silica casing. The FP cavity length between the ends of the SMF and HST changes with the gas density. Using temperature decoupling method to improve the accuracy of the pressure sensor in high temperature environments. An experimental system for measuring the pressure under different temperatures was established to verify the performance of the sensor. The pressure sensitivity of the FP gas pressure sensor is 4.28 nm/MPa with a high linear pressure response over the range of 0.1–0.7 MPa, and the temperature sensitivity is 14.8 pm/°C under the range of 20–800 °C. The sensor has less than 1.5% non-linearity at different temperatures by using temperature decoupling method. The simple fabrication and low-cost will help sensor to maintain the excellent features required by pressure measurement in high temperature applications.
48 citations
TL;DR: In this article, a microfiber-enabled Fabry-Perot interferometer (FPI) constructed by splicing a section of micro-fiber between two cleaved standard single-mode fibers with unique relative fiber cross section relationship has been proposed and experimentally demonstrated.
Abstract: A microfiber-enabled Fabry-Perot interferometer (FPI) constructed by splicing a section of microfiber between two cleaved standard single-mode fibers (SMFs) with unique relative fiber cross section relationship has been proposed and experimentally demonstrated. The opening air cavity between the two SMF ends connected by the microfiber serves as an FP cavity and also a direct sensing head. The sensing characteristics of the FPIs with different cavity lengths and microfiber diameters have been studied. A force sensitivity as high as 167.41 nm/N (~200 pm/μe) and a high refractive index (RI) sensitivity of 1330.8 nm/RIU (around a RI of 1.33) have been achieved by using the microfiber-based FPI with ~21 μm cavity length and ~44 μm microfiber diameter. Such a device has several merits such as simple configuration, compactness and reliability in operation owing to the extremely low thermal cross-sensitivities.
48 citations
Cites background from "Interferometric Fiber Optic Sensors..."
...As two basic physical parameters of great importance for many applications [1]–[14], force and refractive index (RI) were successfully measured by fiber gratings [1], [2] and various in-fiber devices, including single-mode-multimode-single-mode structures [3], [4], fiber loops [5]–[7], Mach-Zehnder interferometers [7]–[10] and Fabry-Pérot interferometers (FPIs) [11]–[14]....
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27 Feb 2019
TL;DR: This systematic review focuses on the differentiating factors of fiber-optic biosensors, which are tailored to apply the sensor to specific health needs, and pays particular attention to alterations made in biosensing elements including pH elements, enzymatic elements, as well as those sensors utilizing antibodies and whole-cell bacteria.
Abstract: In this paper, we provide a brief overview of fiber optic biosensors for use in MedTech, specifically to aid in the diagnoses and treatment of those with chronic medical conditions. Fiber optic cables as components of biological sensors make them especially effective in biological systems that may require ultra-sensitive detection of low-frequency signals in hard to reach areas. This systematic review focuses on the differentiating factors of fiber-optic biosensors, which are tailored to apply the sensor to specific health needs. The main components of FOBS (fiber optic biosensors) such as biosensing elements, fiber optic cables, optical element enhancements, transducers, sensing strategies, photodetectors, and signal processing are covered in detail by showcasing the recent developments in modifications to these components. This paper pays particular attention to the alterations made in biosensing elements including pH elements, enzymatic elements, as well as those sensors utilizing antibodies and whole-cell bacteria. This paper reviews and discusses several published examples in the research stage of development to give the reader an overall scope of the field. The need for research on biosensing equipment is increasing, as the number of individuals with chronic diseases and the geriatric population require more effective, accurate, and mobile sensing ability and reduced invasiveness. FOBS offer a sensing solution that is accurate, tailorable to almost any clinical need, has abundant and relatively cheap material requirements, and a well-established technological base in fiber optic technology. This small price tag and large market potential make FOBS a desirable research area.
46 citations
Cites background from "Interferometric Fiber Optic Sensors..."
...Fluorescence is the simplest of the sensing methods to employ, but it does require more equipment and a fluorescent-based signal to produce results [34,35]....
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...refractometers sensing, telecommunication simple, versatile, self-referenced require design of sensitive layers that change when in contact with the analyte [35]...
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...fluorescence medical applications, chemical sensing and measurements of physical parameters available in different configurations for specific applications require more components and a fluorescent based signal in order to produce results [35]...
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TL;DR: An ultrahigh-sensitivity gas pressure sensor based on the Fabry-Perot interferometer employing a fiber-tip diaphragm-sealed cavity with a gas pressure sensitivity more than two orders of magnitude greater than that of a similarly configured fiber- Tip air bubble sensor is demonstrated.
Abstract: We demonstrate an ultrahigh-sensitivity gas pressure sensor based on the Fabry-Perot interferometer employing a fiber-tip diaphragm-sealed cavity. The cavity is comprised of a silica capillary and ultrathin silica diaphragm with a thickness of 170 nm, with represents the thinnest silica diaphragm fabricated thus far by an electrical arc discharge technique. The resulting Fabry-Perot interferometer-based gas pressure sensor demonstrates a gas pressure sensitivity of about 12.22 nm/kPa, which is more than two orders of magnitude greater than that of a similarly configured fiber-tip air bubble sensor. Moreover, our gas pressure sensor has a low temperature cross-sensitivity of about 106 Pa/°C, and the sensor functions well up to a temperature of about 1000 °C. As such, the sensor can potentially be employed in high-temperature environments.
46 citations
TL;DR: In this article, the authors comprehensively review the recent progress in the micro-structured fiber-optic sensors with a variety of architectures regarding their fabrications, waveguide properties and sensing applications.
Abstract: Recent developments in fiber-optic sensing have involved booming research in the design and manufacturing of novel micro-structured optical fiber devices. From the conventional tapered fiber architectures to the novel micro-machined devices by advanced laser systems, thousands of micro-structured fiber-optic sensors have been proposed and fabricated for applications in measuring temperature, strain, refractive index (RI), electric current, displacement, bending, acceleration, force, rotation, acoustic, and magnetic field. The renowned and unparalleled merits of sensors-based micro-machined optical fibers including small footprint, light weight, immunity to electromagnetic interferences, durability to harsh environment, capability of remote control, and flexibility of directly embedding into the structured system have placed them in highly demand for practical use in diverse industries. With the rapid advancement in micro-technology, micro-structured fiber sensors have benefitted from the trends of possessing high performance, versatilities and spatial miniaturization. Here, we comprehensively review the recent progress in the micro-structured fiber-optic sensors with a variety of architectures regarding their fabrications, waveguide properties and sensing applications.
46 citations
References
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21 Dec 2017
TL;DR: In this paper, the authors present a comprehensive and engaging introduction to optics for intermediate and upper level undergraduate physics and engineering students, which allows instructors to select specialized content to suit individual curricular needs and goals.
Abstract: Introduction to Optics is now available in a re-issued edition from Cambridge University Press. Designed to offer a comprehensive and engaging introduction to intermediate and upper level undergraduate physics and engineering students, this text also allows instructors to select specialized content to suit individual curricular needs and goals. Specific features of the text, in terms of coverage beyond traditional areas, include extensive use of matrices in dealing with ray tracing, polarization, and multiple thin-film interference; three chapters devoted to lasers; a separate chapter on the optics of the eye; and individual chapters on holography, coherence, fiber optics, interferometry, Fourier optics, nonlinear optics, and Fresnel equations.
927 citations
TL;DR: A detailed mechanism of the surface plasmon resonance (SPR) technique for sensing purposes has been discussed in this paper, where different new techniques and models in this area that have been introduced are discussed in quite a detail.
Abstract: Since the introduction of optical fiber technology in the field of sensor based on the technique of surface plasmon resonance (SPR), fiber-optic SPR sensors have witnessed a lot of advancements. This paper reports on the past, present, and future scope of fiber-optic SPR sensors in the field of sensing of different chemical, physical, and biochemical parameters. A detailed mechanism of the SPR technique for sensing purposes has been discussed. Different new techniques and models in this area that have been introduced are discussed in quite a detail. We have tried to put the different advancements in the order of their chronological evolution. The content of the review article may be of great importance for the research community who are to take the field of fiber-optic SPR sensors as its research endeavors.
824 citations
TL;DR: In this paper, an approach to achieve simultaneous measurement of refractive index and temperature is proposed by using a Mach-Zehnder interferometer realized on tapered single-mode optical fiber.
Abstract: An approach to achieve simultaneous measurement of refractive index and temperature is proposed by using a Mach–Zehnder interferometer realized on tapered single-mode optical fiber. The attenuation peak wavelength of the interference with specific order in the transmission spectrum shifts with changes in the environmental refractive index and temperature. By utilizing S-band and C/L-band light sources, simultaneous discrimination of refractive index and temperature with the tapered fiber Mach–Zehnder interferometer is demonstrated with the corresponding sensitivities of −23.188 nm/RIU (refractive index unit) and 0.071 nm/ °C, and −26.087 nm/RIU (blueshift) and 0.077 nm/°C (redshift) for the interference orders of 169 and 144, respectively.
551 citations
"Interferometric Fiber Optic Sensors..." refers background in this paper
...By tapering a fiber at two points along the fiber, we can form an effective in-line MZI as shown in Figure 7(f) [55,56]....
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TL;DR: In this article, a fiber-based Fabry-Perot cavity with CO2 laser-machined mirrors was realized, which combines very small size, high finesse, small waist and mode volume, and good mode matching between the fiber and cavity modes.
Abstract: We have realized a fiber-based Fabry-Perot cavity with CO2 laser-machined mirrors. It combines very small size, high finesse F>=130000, small waist and mode volume, and good mode matching between the fiber and cavity modes. This combination of features is a major advance for cavity quantum electrodynamics (CQED), as shown in recent CQED experiments with Bose-Einstein condensates enabled by this cavity [Y. Colombe et al., Nature 450, 272 (2007)]. It should also be suitable for a wide range of other applications, including coupling to solid-state emitters, gas detection at the single-particle level, fiber-coupled single-photon sources and high-resolution optical filters with large stopband.
418 citations
"Interferometric Fiber Optic Sensors..." refers background in this paper
...Since it can utilize high reflecting mirrors, the extrinsic structure is useful to obtain a high finesse interference signal [23]....
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TL;DR: As potential applications of the all-PCF interferometer, strain sensing is experimentally demonstrated and ultra-high temperature sensing is proposed.
Abstract: We propose simple and compact methods for implementing all-fiber interferometers. The interference between the core and the cladding modes of a photonic crystal fiber (PCF) is utilized. To excite the cladding modes from the fundamental core mode of a PCF, a coupling point or region is formed by using two methods. One is fusion splicing two pieces of a PCF with a small lateral offset, and the other is partially collapsing the air-holes in a single piece of PCF. By making another coupling point at a different location along the fiber, the proposed all-PCF interferometer is implemented. The spectral response of the interferometer is investigated mainly in terms of its wavelength spectrum. The spatial frequency of the spectrum was proportional to the physical length of the interferometer and the difference between the modal group indices of involved waveguide modes. For the splicing type interferometer, only a single spatial frequency component was dominantly observed, while the collapsing type was associated with several components at a time. By analyzing the spatial frequency spectrum of the wavelength spectrum, the modal group index differences of the PCF were obtained from 2.83×10-3 to 4.65 ×10-3 . As potential applications of the all-PCF interferometer, strain sensing is experimentally demonstrated and ultra-high temperature sensing is proposed.
418 citations
"Interferometric Fiber Optic Sensors..." refers background or methods in this paper
...However, in this case, coupling to several cladding modes was observed and controlling the number of involved modes was not so simple [51]....
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...Even with PCF, an MZI can be formed by simply fusion-splicing a piece of PCF between fibers with a small intentional deviation [51]....
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...In reference [51], as low as 2 dB splicing loss was achieved by making the mode coupling to dominantly one cladding mode of the PCF....
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