Tailoring Optical Fibers With Application-Specific Physical Properties for Sensing Systems

2016 ◽  
Author(s):  
P.D. Dragic ◽  
C. Ryan ◽  
C.J. Kucera ◽  
M. Cavillon ◽  
M. Tuggle ◽  
...  
Keyword(s):  
Physical Properties ◽  
Optical Fibers ◽  
Sensing Systems ◽  
Application Specific

scholarly journals Mid-Infrared Waveguides: A Perspective

2016 ◽  
Vol 70 (10) ◽  
pp. 1625-1638 ◽  
Author(s):  
Thomas Schädle ◽  
Boris Mizaikoff
Keyword(s):  
Optical Fibers ◽  
First Generation ◽  
Classification Scheme ◽  
State Of The Art ◽  
Third Generation ◽  
Future Trends ◽  
Mid Infrared ◽  
Mir Spectroscopy ◽  
Sensing Systems ◽  
Infrared Waveguides

Significant advancements in waveguide technology in the mid-infrared (MIR) regime during recent decades have assisted in establishing MIR spectroscopic and sensing technologies as a routine tool among nondestructive analytical methods. In this review, the evolution of MIR waveguides along with state-of-the-art technologies facilitating next-generation MIR chem/bio sensors will be discussed introducing a classification scheme defining three “generations” of MIR waveguides: (1) conventional internal reflection elements as “first generation” waveguides; (2) MIR-transparent optical fibers as “second generation” waveguides; and most recently introduced(3) thin-film structures as “third generation” waveguides. Selected application examples for these each waveguide category along with future trends will highlight utility and perspectives for waveguide-based MIR spectroscopy and sensing systems.

scholarly journals Optical Sensing of Nitrogen, Phosphorus and Potassium: A Spectrophotometrical Approach Toward Smart Nutrient Deployment

Chemosensors ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 51 ◽  
Author(s):  
Monteiro-Silva ◽  
Jorge ◽  
Martins
Keyword(s):  
Optical Fibers ◽  
Regression Models ◽  
Sensing Systems ◽  
Vis Spectroscopy ◽  
Artificial Intelligence Algorithm ◽  
Phosphorus And Potassium ◽  
Micro Irrigation ◽  
Self Learning ◽  
Nitrogen Phosphorus ◽  
Nutrient Solutions

The feasibility of a compact, modular sensing system able to quantify the presence of nitrogen, phosphorus and potassium (NPK) in nutrient-containing fertilizer water was investigated. Direct UV-Vis spectroscopy combined with optical fibers were employed to design modular compact sensing systems able to record absorption spectra of nutrient solutions resulting from local producer samples. N, P, and K spectral interference was studied by mixtures of commercial fertilizer solutions to simulate real conditions in hydroponic productions. This study demonstrates that the use of bands for the quantification of nitrogen with linear or logarithmic regression models does not produce analytical grade calibrations. Furthermore, multivariate regression models, i.e., Partial Least Squares (PLS), which consider specimens interference, perform poorly for low absorbance nutrients. The high interference present in the spectra has proven to be solved by an innovative self-learning artificial intelligence algorithm that is able to find interference modes among a spectral database to produce consistent predictions. By correctly modeling the existing interferences, analytical grade quantification of N, P, and K has proven feasible. The results of this work open the possibility of real-time NPK monitoring in Micro-Irrigation Systems.

Low-Cost Sensing with Plastic Optical Fibers—From Turbidity and Refractive Index to Chemical Sensing

Proceedings ◽  
2019 ◽  
Vol 15 (1) ◽  
pp. 12
Author(s):  
Filipa Sequeira ◽  
Daniel Duarte ◽  
Rogério Nogueira ◽  
Lúcia Bilro
Keyword(s):  
Refractive Index ◽  
Quality Assessment ◽  
Optical Fibers ◽  
Chemical Sensing ◽  
Low Cost ◽  
Research Groups ◽  
Water Contaminants ◽  
Sensing Systems ◽  
Site Monitoring ◽  
Plastic Optical Fibers

This manuscript presents low-cost sensing systems for the monitoring of liquids, namely water and beverages quality assessment, with remote and in-site monitoring capabilities. The collaboration with several research groups allowed the development of smart optical platforms and low-cost sensors based on plastic optical fibers for the measurement of turbidity, color, refractive index and water contaminants.

scholarly journals Laser-Based Trace Gas Detection inside Hollow-Core Fibers: A Review

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3983
Author(s):  
Michal Nikodem
Keyword(s):  
Optical Fibers ◽  
Gas Sensing ◽  
Photonic Band Gap ◽  
Gas Detection ◽  
Trace Gas ◽  
Hollow Core ◽  
Trace Gas Detection ◽  
Optical Wave ◽  
Sensing Systems ◽  
Photonic Band

Thanks to the guidance of an optical wave in air, hollow-core fibers may serve as sampling cells in an optical spectroscopic system. This paper reviews applications of hollow-core optical fibers to laser-based gas sensing. Three types of hollow-core fibers are discussed: Hollow capillary waveguides, photonic band-gap fibers, and negative curvature fibers. Their advantages and drawbacks when used for laser-based trace gas detection are analyzed. Various examples of experimental sensing systems demonstrated in the literature over the past 20 years are discussed.

scholarly journals Locating Graves with Geophysics

2021 ◽  
Author(s):  
Ian Moffat
Keyword(s):  
Physical Properties ◽  
Survey Methodology ◽  
Successful Outcome ◽  
Density Data ◽  
Non Invasive ◽  
Geophysical Techniques ◽  
Comprehensive Survey ◽  
Survey Strategy ◽  
Ultrahigh Density ◽  
Application Specific

The detection and mapping of unmarked graves is a significant focus of many archaeological and forensic investigations however traditional methods such as probing, forensic botany, cadaver dogs or dowsing are often ineffective, slow to cover large areas or excessively invasive. Geophysics offers an appealing alternative suitable for the rapid non invasive investigation of large areas. Unfortunately graves are a challenging target with no diagnostic geophysical response and so the use of a rigorous application-specific methodology is essential for a successful outcome. The most important inclusions in a successful survey methodology include ultrahigh density data, the use of multiple geophysical techniques to validate results based on several physical properties, excellent quality positioning and intensive site recording. Regardless of the methodology applied, geophysics should not be considered a panacea for locating all graves on all sites but should be used as an integral part of a comprehensive survey strategy.

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