Optical Fiber-Based Wave Mixing as a Convenient and Sensitive Laser Analytical Tool for Condensed-Phase Analytes

A fiber-optic degenerate four-wave mixing (D4WM) probe for the measurement of small absorptions in liquid-phase samples is described. Laser D4WM is a nonlinear laser spectroscopic technique that has proven to be highly sensitive for the detection of trace analytes in condensed-phase media. A significant improvement in the forward-scattering optical arrangement of D4WM is demonstrated by using optical fibers for both laser light input and output. There is considerable flexibility inherent in the design since the system may be used in three configurations: (1) the simplest case of transmitting the signal radiation by optical fiber to the detection electronics, (2) the case of guiding the excitation beams to the analyte by polarization-maintaining optical fibers, and (3) the combination of both. The optical fiber-based D4WM system is shown to be an effective and sensitive laser analytical spectroscopic method for trace analysis, offering advantages such as detection in very small probe volumes, remote and in situ analysis, and convenient and efficient optical alignment enhancements obtained by the use of optical fibers.

Download Full-text

An Optical Fiber Chemical Sensor for the Detection of Copper(II) in Drinking Water

Sensors ◽

10.3390/s19235246 ◽

2019 ◽

Vol 19 (23) ◽

pp. 5246 ◽

Cited By ~ 3

Author(s):

Pesavento ◽

Profumo ◽

Merli ◽

Cucca ◽

Zeni ◽

...

Keyword(s):

Drinking Water ◽

Optical Fiber ◽

Optical Fibers ◽

Chemical Sensor ◽

Low Cost ◽

Self Assembled Monolayer ◽

Ph Values ◽

Highly Sensitive ◽

Selective Sensor

Highly sensitive plasmonic optical fiber platforms combined with receptors have been recently used to obtain selective sensors. A low-cost configuration can be obtained exploiting a D-shaped plastic optical fiber covered with a multilayer sensing surface. The multilayer consists of a gold film, functionalized with a specific receptor, where the surface plasmon resonance (SPR) occurs. The signal is produced by the refractive index variation occurring as a consequence of the receptor-to analyte binding. In this work, a selective sensor for copper(II) detection in drinking water, exploiting a self-assembled monolayer (SAM) of d,l-penicillamine as the sensing layer, has been developed and tested. Different concentrations of copper(II) in NaCl 0.1 M solutions at different pH values and in a real matrix (drinking water) have been considered. The results show that the sensor is able to sense copper(II) at concentrations ranging from 4 × 10-6 M to 2 × 10-4 M. The use of this optical chemical sensor is a very attractive perspective for fast, in situ and low-cost detection of Cu(II) in drinking water for human health concerns. Furthermore, the possibility of remote control is feasible as well, because optical fibers are employed.

Download Full-text

Flexible porphyrin doped polymer optical fibers for rapid and remote detection of trace DNT vapor

The Analyst ◽

10.1039/d0an00706d ◽

2020 ◽

Vol 145 (15) ◽

pp. 5307-5313

Author(s):

Huan Lin ◽

Xin Cheng ◽

Ming-Jie Yin ◽

Zhouzhou Bao ◽

Xunbin Wei ◽

...

Keyword(s):

Optical Fiber ◽

Optical Fibers ◽

Remote Detection ◽

Polymer Optical Fiber ◽

Highly Sensitive ◽

Polymer Optical Fibers ◽

Doped Polymer

A flexible porphyrin doped polymer optical fiber was developed for fast and highly sensitive monitoring of DNT vapors.

Download Full-text

In situ growth of Au–Ag bimetallic nanorings on optical fibers for enhanced plasmonic sensing

Journal of Materials Chemistry C ◽

10.1039/d0tc01253j ◽

2020 ◽

Vol 8 (22) ◽

pp. 7552-7560 ◽

Cited By ~ 1

Author(s):

Se Shi ◽

Anran Li ◽

Renliang Huang ◽

Jing Yu ◽

Shuzhou Li ◽

...

Keyword(s):

Optical Fiber ◽

Oxidation Resistance ◽

Optical Fibers ◽

Fiber Surface ◽

Metal Deposition ◽

In Situ Growth ◽

Plasmonic Sensing

Au–Ag bimetallic nanorings were grown in situ on an optical fiber surface via bioinspired PDA, a synergetic GRR and metal deposition, which exhibited enhanced LSPR sensitivity and oxidation resistance.

Download Full-text

Development of Highly Sensitive Raman Spectroscopy for Subnano and Single-Atom Detection

Molecules ◽

10.3390/molecules26165099 ◽

2021 ◽

Vol 26 (16) ◽

pp. 5099

Author(s):

Yuansen Tang ◽

Naoki Haruta ◽

Akiyoshi Kuzume ◽

Kimihisa Yamamoto

Keyword(s):

Large Scale ◽

Direct Detection ◽

Spectroscopic Technique ◽

Single Atom ◽

Comprehensive Understanding ◽

Experimental Conditions ◽

Highly Sensitive ◽

Atom Detection ◽

Small Targets

Direct detection and characterisation of small materials are fundamental challenges in analytical chemistry. A particle composed of dozens of metallic atoms, a so-called subnano-particle (SNP), and a single-atom catalyst (SAC) are ultimate analysis targets in terms of size, and the topic is now attracting increasing attention as innovative frontier materials in catalysis science. However, characterisation techniques for the SNP and SAC adsorbed on substrates requires sophisticated and large-scale analytical facilities. Here we demonstrate the development of an ultrasensitive, laboratory-scale, vibrational spectroscopic technique to characterise SNPs and SACs. The fine design of nano-spatial local enhancement fields generated by the introduction of anisotropic stellate-shaped signal amplifiers expands the accessibility of small targets on substrates into evanescent electromagnetic fields, achieving not only the detection of isolated small targets but also revealing the effects of intermolecular/interatomic interactions within the subnano configuration under actual experimental conditions. Such a development of “in situ subnano spectroscopy” will facilitate a comprehensive understanding of subnano and SAC science.

Download Full-text

Towards Distributed Measurements of Electric Fields Using Optical Fibers: Proposal and Proof-Of-Concept Experiment

Sensors ◽

10.3390/s20164461 ◽

2020 ◽

Vol 20 (16) ◽

pp. 4461 ◽

Cited By ~ 1

Author(s):

Regina Magalhães ◽

João Pereira ◽

Oleksandr Tarasenko ◽

Sonia Martin-Lopez ◽

Miguel González-Herráez ◽

...

Keyword(s):

Optical Fiber ◽

Electric Fields ◽

Optical Fibers ◽

Electromagnetic Interference ◽

Time Domain Reflectometry ◽

Second Order ◽

Third Order ◽

Electrical Fields ◽

Silica Fibers ◽

Highly Sensitive

Nowadays there is an increasing demand for the cost-effective monitoring of potential threats to the integrity of high-voltage networks and electric power infrastructures. Optical fiber sensors are a particularly interesting solution for applications in these environments, due to their low cost and positive intrinsic features, including small size and weight, dielectric properties, and invulnerability to electromagnetic interference (EMI). However, due precisely to their intrinsic EMI-immune nature, the development of a distributed optical fiber sensing solution for the detection of partial discharges and external electrical fields is in principle very challenging. Here, we propose a method to exploit the third-order and second-order nonlinear effects in silica fibers, as a means to achieve highly sensitive distributed measurements of external electrical fields in real time. By monitoring the electric-field-induced variations in the refractive index using a highly sensitive Rayleigh-based CP-φOTDR scheme, we demonstrate the distributed detection of Kerr and Pockels electro-optic effects, and how those can assign a new sensing dimension to optical fibers, transducing external electric fields into visible minute disturbances in the guided light. The proposed sensing configuration, electro-optical time domain reflectometry, is validated both theoretically and experimentally, showing experimental second-order and third-order nonlinear coefficients, respectively, of χ(2) ~ 0.27 × 10−12 m/V and χ(3) ~ 2.5 × 10−22 m2/V2 for silica fibers.

Download Full-text

Highly Sensitive Optical Fiber Photoacoustic Sensor for in situ Detection of Dissolved Gas in Oil

IEEE Transactions on Instrumentation and Measurement ◽

10.1109/tim.2021.3102746 ◽

2021 ◽

pp. 1-1

Author(s):

Ke Chen ◽

Min Guo ◽

Beilei Yang ◽

Feng Jin ◽

Guangzhen Wang ◽

...

Keyword(s):

Optical Fiber ◽

Dissolved Gas ◽

Highly Sensitive ◽

In Situ Detection

Download Full-text

Use of Optical Fiber Sensor for Monitoring the Degradation of Ac-Dex Biopolymeric Nanoparticles

Proceedings ◽

10.3390/ecsa-6-06535 ◽

2019 ◽

Vol 42 (1) ◽

pp. 12

Author(s):

Marco César Prado Soares ◽

Gabriel Perli ◽

Matheus Kauê Gomes ◽

Carolyne Brustolin Braga ◽

Diego Luan Bertuzzi ◽

...

Keyword(s):

Optical Fiber ◽

Optical Fibers ◽

Optical Fiber Sensor ◽

Single Mode ◽

Spherical Particles ◽

Fiber Sensor ◽

Elastic Light Scattering ◽

Modified Polymer ◽

Degradation Pattern

Abstract: Acetalated dextran (Ac-Dex) is a promising pH-sensitive biocompatible and biodegradable polymer for nanomedicine applications. In this work, Ac-Dex nanoparticles were synthesized by two different solvent evaporation methods, the single nanoemulsion and the double nanoemulsion. The Ac-Dex particles were characterized by scanning electron microscopy and the synthesis of highly homogeneous spherical particles was verified. Then, an optical fiber sensor based on quasi-elastic light scattering and comprised of only single-mode optical fibers and standard telecommunication devices showed sensitivity regarding the nanoparticles concentrations and was used for monitoring their degradation over 12 h under pH and temperature conditions of cancerous tissues. The results revealed a well-controlled degradation pattern, corroborating the suitability of the modified polymer to the release of active compounds in a sustainable manner and also demonstrating the applicability of the sensor for the in situ evaluation of the degradation.

Download Full-text