Requirements for gain/oscillation in Yb3+/Er3+-codoped microring resonators

A detailed model of the performance of a highly Yb3+/Er3+-codoped phosphate glass add-drop filter, which combines the propagation at resonance of both pump and signal powers inside the microring resonator with their interaction with the dopant ions, is used to analyze the requirements for gain/oscillation in these structures. Special attention is paid to the influence of additional coupling losses and asymmetry between the input/output couplers. It is concluded that, due to small signal gain saturation and the limited range of pump amplitude coupling coefficients, asymmetry does not greatly influence gain/oscillation requirements through the pump intensity build-up inside the ring. Asymmetry effect on small signal intensity transfer rate and threshold gain instead allows a significant lightening of the demanding doping ions concentrations requirements to achieve oscillation

Optimal Design of D-type Plastic Fibers for best sensitivity of SPR Sensors

Abstract. A design method for a SPR (surface plasmon resonance) sensor based on a D-type plastic optical fiber (POF) geometry in a configuration of a multi-layered scheme is proposed in this paper. The numerical simulation for the optimal sensitivity with spectral interogation was performed in order to choose the practical implementation geometry of the SPR sensor. A side-polish to the half of the fiber's PMMA core, with about 10mm in length is made and a Microposit 1813 buffer and gold layer deposition is used for sample fabrication. The effect of different thickness of the layers in different multi-layered configuration has been investigated. The proposed setup for sensor test, measures the light intensity instead of phase difference. It can be used for refractive index changes (1.33-1.40) in real time detection of the substances for different biosensing applications. The proposed sensor is simple to use, has small size, it works on small analyt-sample size and it is cost effective for specific non-invasive application users

Magnetic Nanoparticles for Antibiotics Detection

Widespread use of antibiotics has led to pollution of waterways, potentially creating resistance among freshwater bacterial communities. Microorganisms resistant to commonly prescribed antibiotics (superbug) have dramatically increased over the last decades. The presence of antibiotics in waters, in food and beverages in both their un-metabolized and metabolized forms are of interest for humans. This is due to daily exposure in small quantities, that, when accumulated, could lead to development of drug resistance to antibiotics, or multiply the risk of allergic reaction. Conventional analytical methods used to quantify antibiotics are relatively expensive and generally require long analysis time associated with the difficulties to perform field analyses. In this context, electrochemical and optical based sensing devices are of interest, offering great potentials for a broad range of analytical applications. This review will focus on the application of magnetic nanoparticles in the design of different analytical methods, mainly sensors, used for the detection of antibiotics in different matrices (human fluids, the environmental, food and beverages samples)

Experimental results for characterization of a tapered plastic optical fiber sensor based on SPR

The 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

Effect of heat-treatment on the upconversion of NaYF4:Yb3+, Er3+ nanocrystals containing silver phosphate glass

Novel NaYF4:Yb3+, Er3+ nanocrystals containing phosphate glass with composition 83.25NaPO3–9.25NaF-5ZnO-2.5Ag2O (in mol%) was prepared by adding the NaYF4:Yb3+, Er3+ nanocrystals in the glass using the direct doping method. The optical and luminescence properties of this new glass are presented and discussed. The newly developed glass exhibits visible emission under 980 nm pumping with high intensity confirming the presence of the NaYF4:Yb3+, Er3+ nanocrystals in the glass. From the absorption spectrum of the as-prepared glass, it is showed that the as-prepared glasses contains already Ag nanoparticles which are thought to precipitate due to the decomposition of some of the NaYF4:Yb3+, Er3+ nanocrystals occurring during the glass preparation. A heat treatment of the glass was found to lead to the migration of Ag species at the surface of the glass as evidenced using SEM and to a decrease of the intensity of the upconversion mostly due to an increase of the inter defects in the NaYF4:Yb3+, Er3+ nanocrystals due to the heat treatment.acceptedVersionPeer reviewe

0121_CHN_1930

In data transmission systems there are applications where lateral coupling light is requested. Fluorescent optical fibers radiate light as a response to incident illumination along the side. Because of photosensitivity along the side, the plastic photo-luminescent fiber is considered a flexible coupling alternative of the light, instead of discrete position coupler or tap. Fluorescent optical fibers have been investigated for data transmission applications. With commercially available fluorescent fiber for the optical bus system and smartphone based data transmission (ASK modulation) the data rates up to 500Mbit/s are feasible, by selecting the right parameters such as short fluorescence lifetime, spectral region of the fibers correlated with light sources and photodetectors and in-fiber low spectral attenuation. The application is useful in automotive applications for data transmission and distributed sensing

Optimal Design of D-Type Plastic Fibers for Best Sensitivity of SPR Sensors

A design method for a SPR (surface plasmon resonance) sensor based on a D-type plastic optical fiber (POF) geometry in a configuration of a multi-layered scheme is proposed in this paper. The numerical simulation for the optimal sensitivity with spectral interogation was performed in order to choose the practical implementation geometry of the SPR sensor. A side-polish to the half of the fiber's PMMA core, with about 10mm in length is made and a Microposit 1813 buffer and gold layer deposition is used for sample fabrication. The effect of different thickness of the layers in different multi-layered configuration has been investigated. The proposed setup for sensor test, measures the light intensity instead of phase difference. It can be used for refractive index changes (1.33-1.40) in real time detection of the substances for different biosensing applications. The proposed sensor is simple to use, has small size, it works on small analyt-sample size and it is cost effective for specific non-invasive application users

Integrated system SPR array sensors based on side glow MMA fibers

The integrated system consisting of a customized number of plasmonic sensors array is presented (N=2). The 1mm diameter MMA polymer core, side emitting fibers are used for plasmonic sensors implementation. Time domain monitoring of the fiber based plasmonic sensors with a spectroscopy application for smartphone is portable and low energy-consuming solution for environment applications

Performance Comparison of Two Sensors Based on Surface Plasmon Resonance in a Plastic Optical Fiber

In silica optical fiber Surface Plasmon Resonance (SPR)-based sensors, an increase in fiber core diameter produces a corresponding increase in the sensitivity and Signal to Noise Ratio (SNR). In Plastic Optical Fiber (POF) realized in PMMA there are different influences of design parameters on the performance, as both sensitivity and SNR are concerned. In particular, the SNR, for different refractive index values of the analyte, in a 250 μm diameter POF is greater than the one in 1,000 μm diameter POF. On the other hand, the sensitivity, for the same refractive index values of the analyte, in a 1,000 μm diameter POF is greater than the one in a 250 μm diameter POF. The results of an experimental analysis demonstrating the above behavior are reported

Plasmonic Sensing in D-Shaped POFs with Fluorescent Optical Fibers as Light Sources

We present a new experimental investigation about the possibility to use fluorescent optical fibers as light sources, instead of halogen lamps, for plasmonic sensing. The novel configuration has been first introduced, and then the components' properties and the experimental results have been illustrated. Two sensor systems have been realized and characterized by exploiting red and blue fluorescent optical fibers to illuminate different plasmonic sensors and observe the transmitted spectra by a spectrometer. In particular, the plasmonic sensors have been realized with two different metals, gold and silver, sputtered on D-shaped plastic optical fibers (POFs) with an optical buffer layer between the metal film and the POF core. We have matched the metal's plasmonic resonance wavelength with the emission of a specific fluorescent optical fiber. The good quality of the experimental results, the low-power consumption, the low cost, the remote sensing capability, the small size, and the simple scheme of the configuration make this strategy a potentially suitable diagnostic tool for biosensing applications