1,721,250 research outputs found
Novel approaches to realize plasmonic intrinsic and extrinsic optical fiber sensors with high sensitivity
No full textAuthors recall two high sensitive, small size, and low-cost surface plasmon resonance (SPR) sensors based on plastic optical fibers (POFs): the first one, a D-shaped SPR intrinsic POF sensor, the second one an SPR extrinsic POF sensor. These plasmonic POF sensors, intrinsic and extrinsic, combined with different kinds of specific receptors can be directly connected to an online platform by a software interface, allowing storing, analyzing and displaying the sensor's data, to realize low-cost biochemical sensors for several applications. The simple experimental setup, used for both these SPR POF sensor configurations, was arranged to measure the light spectrum transmitted through the plasmonic platform, exploiting a halogen lamp and a spectrometer connected to a PC
Exploiting Plasmonic Phenomena in Polymer Optical Fibers to Realize a Force Sensor
No full textIn this work, a novel sensing approach to realize a force optical fiber sensor is designed, developed, and experimentally tested. The proposed sensing methodology exploits the effects of deformation due to an applied force on a patch of plastic optical fiber (POF) connected at the input of a surface plasmon resonance (SPR) sensor realized in a D-shaped POF. Therefore, the proposed force sensor system consists of an SPR D-shaped POF sensor, connected to a spectrometer, within input of a POF patch, connected to a light source used for interacting with the applied force. When the applied force on the patch changes, the mode profile of the light in the multimode POF patch and the SPR-POF sensor change too, so the SPR spectra shift. The obtained experimental results demonstrate that the proposed sensor has a resolution of the force sensor equal to about 22 mN and an excellent linear response in the range from 0 N to 0.5 N
Hybrid BOFDA/BOCDA system for distributed static and dynamic strain measurements
No full textWe present a distributed optical fiber sensor based on a hybrid Brillouin optical frequency/correlation-domain analysis (BOFDA/BOCDA) configuration for both static and dynamic strain measurements. Distributed static strain (or temperature) measurements are realized using the conventional BOFDA method, i.e., acquiring the baseband transfer function of the fiber through a vector network analyzer (VNA). With little modifications, the same setup can perform dynamic, position-selective measurements synthesizing a correlation peak through a frequency modulation of the laser source while operating the VNA at a single modulation frequency. Experimental tests, carried out at a sampling frequency up to 40 Hz and a spatial resolution of ≈5 cm, demonstrate the validity of the proposed approach
Design and analysis of an integrated antiresonant reflecting optical waveguide refractive-index sensor
No full textA review on simple and highly sensitive plastic optical fiber probes for bio-chemical sensing
No full textA review on bio-chemical label-free sensing applications based on receptors combined with multimode plastic optical fibers (POFs) is carried out. In particular, this work focuses on different kinds of POF intrinsic sensors used in transmission mode, exploiting various types of receptors and useful in several application fields. The sensor structures and the sensing mechanisms of different simple, highly sensitive, and low-cost POF probes are reported and compared. Moreover, different kinds of chemical and biological receptors combined with POF probes, highlighting the advantages and disadvantages of each receptor, are presented in detail. More specifically, the chosen POF sensing platforms, including low-cost and simple interrogation setups, are described showing their ability to monitor specific receptors exploiting intensity variation techniques and plasmonic phenomena, as well. Finally, a prospect of future developments of biochemical sensors with multimode POFs is discussed
Polymer Optical Fibers for Sensing
No full textSensing techniques based on optical fibers are used in numerous key fields. For example, optical fiber sensors are exploited in medical diagnostics, environmental monitoring, physical parameters detection, industrial applications, food safety, and security. In fact, optical fiber sensors are used for their numerous capabilities, as for example when in the detection fast, portable, low-cost, small size, and/or rugged sensor systems are needed. In general, the optical fiber for sensing applications can be a glass one, a specialty one, or a polymer one. Polymer optical fibers (POFs) are especially advantageous due to their excellent flexibility, easy manipulation, large diameter, resilience, and the fact that plastic is able to withstand smaller bend radii than glass. These POF sensors, intrinsic and extrinsic, combined with different kinds of receptors can be directly connected to an online platform by interface software, allowing storing, analyzing, and displaying the sensor's data, to realize low-cost biochemical sensors for several applications. In this work, two plasmonic POF sensors, one intrinsic and another one extrinsic, that can be used in biochemical applications are described
Experimental results for characterization of a tapered plastic optical fiber sensor based on SPR
No full textThe experimental results obtained with two different Plastic Optical Fiber (POF) geometries, tapered and not-tapered, for a sensor based on Surface Plasmon Resonance (SPR) are presented. SPR is used for determining the refractive index variations at the interface between a gold layer and a dielectric medium (aqueous medium). In this work SPR sensors in POF configurations, useful for bio-sensing applications, have been realized for the optimization of the sensitivity and experimentally tested. The results show as the sensitivity increases with the tapered POF configuration, when the refractive index of aqueous medium increases
ARROW structures for sensing applications
No full textIn this paper two sensing applications of Antiresonant Reflecting Optical Waveguide (ARROW) structures are proposed. In the first, we show that, by a suitable design, a conventional ARROW waveguide can be turned in an integrated optical refractometer useful in chemical and biochemical sensing. In the second application, using some peculiar properties of ARROW structures, we have designed and realized an integrated flow cell by an hollow core ARROW waveguide
Highly Sensitive Plasmonic Sensors and Biosensors realized via modified Specialty Optical Fibers
No full textSeveral developed low-cost, highly sensitive, and simple to realize and to use plasmonic sensor configurations will be here recalled. In particular, the proposed sensor configurations are based on unconventional platforms that efficiently excite the plasmonic phenomena in gold nanofilms, continuous on nanostructured, such as polymer optical fibers and light-diffusing fibers (LDFs). The presented plasmonic sensor chips are monitored using a simple experimental setup based on a white light source and a spectrometer. Moreover, the proposed platforms can be combined with chemical and biological receptors in several application fields. In these cases, we can obtain the selectivity for the substances of interest via specific Molecular Recognition Elements (MREs) in contact with the plasmonic sensing surfaces, such as those based on molecularly imprinted polymers (MIPs), antibodies, aptamers, and nanoMIPs. The substances measured with the proposed approach are pollutants, viruses, bacteria, toxic metals, pesticides, or other molecules of interest in aqueous solutions. So, the advantages and disadvantages of each biochemical sensor system are presented in detail. More specifically, plasmonic extrinsic and intrinsic optical fiber sensor types will be reported in terms of plasmonic characteristics and key application fields
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