The Effect of Length and Diameter on the Signal-to-Noise Ratio of Evanescent Field Absorption Fiber-Optic Sensors

1992 ◽  
Vol 46 (7) ◽  
pp. 1129-1133 ◽  
Author(s):  
T. B. Colin ◽  
K.-H. Yang ◽  
M. A. Arnold ◽  
Gary W. Small ◽  
W. C. Stwalley
Keyword(s):  
Near Infrared ◽  
Fiber Optic ◽  
Signal To Noise Ratio ◽  
Fiber Optic Sensors ◽  
Evanescent Field ◽  
Infrared Sensor ◽  
Signal To Noise ◽  
Optimal Length ◽  
Sensor Applications ◽  
Field Sensor

This paper discusses the theoretical and experimental implications of changing the length and diameter of the evanescent field sensing region of an evanescent field sensor. Particular emphasis is placed on optimizing the intensity of the evanescent field for near-infrared sensor applications. Both theoretical and experimental results show that an optimal length and diameter must be determined experimentally for each analyte system.

Local high edge observation for the bonding line monitoring of a complex composite beam

2020 ◽  
pp. 095440622093219
Author(s):  
Monica Ciminello ◽  
Bernardino Galasso ◽  
Gianvito Apuleo ◽  
Shay Shoam ◽  
Antonio Concilio
Keyword(s):  
Strain Field ◽  
Composite Beam ◽  
Composite Structures ◽  
Longitudinal Strain ◽  
Fiber Optic ◽  
Signal To Noise Ratio ◽  
Fiber Optic Sensors ◽  
Signal To Noise ◽  
Mechanical Loads ◽  
Spatial Domains

The most part of defects in composite structures carrying attached subelements is the disbond at the interface, as the skin/stringer sections. This is sometimes due to a nonoptimal manufacturing process or sometimes due to accidental object impacts during service. It has been verified that structural discontinuities within an elastic medium under mechanical loads can cause analogous discontinuities within the strain field. Starting from this analysis, the present work investigates the effect of artificially induced kissing bond areas just at the in the skin–stiffener interface of an aeronautical complex composite beam. This research uses longitudinal strain values, acquired at the locations where distributed fiber optic sensors are installed. The applied methodology uses different strain-based features providing local high edge observation both in time and spatial domains. Their autocorrelations are, in the end, computed to improve signal-to-noise ratio. The local high edge observation algorithm is proposed that proves its capability to monitor disbond being at the same time load and baseline independent.

Component Selection for Fiber-Optic Fluorometry

1990 ◽  
Vol 44 (1) ◽  
pp. 117-122 ◽  
Author(s):  
Richard B. Thompson ◽  
Michael Levine ◽  
Lynne Kondracki
Keyword(s):  
Systematic Study ◽  
Fiber Optic ◽  
Signal To Noise Ratio ◽  
Fiber Optic Sensors ◽  
Fluorescence Sensor ◽  
Measured Signal ◽  
Optimized Design ◽  
Signal To Noise ◽  
Component Selection ◽  
Selection For

A wide variety of fiber-optic sensors based on fluorescence have been developed for important applications in the last few years. Unfortunately, no systematic study describing an optimized design has appeared. A fiber-optic fluorescence sensor testbed was constructed, and different optical designs and components were compared for sensitivity in detecting fluorescence. Different beamsplitters, launching objectives, filters, detectors, and configurations were evaluated on the basis of their measured signal-to-noise ratio in detecting 100 picomolar fluorescein. Sources of noise and background were identified, and generally applicable means for minimizing them are described.

Optimization of Silicon Nitride Y-Branch Optical Waveguide for Evanescent Field Biosensor

2014 ◽  
Vol 875-877 ◽  
pp. 1183-1188 ◽  
Author(s):  
Khor Kang Nan ◽  
M.M. Shahimin ◽  
F.R.M. Adikan
Keyword(s):  
Silicon Nitride ◽  
Optical Waveguide ◽  
Chemical Sensors ◽  
Power Loss ◽  
Signal To Noise Ratio ◽  
High Sensitivity ◽  
Evanescent Field ◽  
Signal To Noise ◽  
Field Sensor ◽  
Effective Angle

Evanescent field had been widely used in bio and chemical sensors. However in most cases, evanescent field is not maximized and thus the performance of the sensor is not optimized. It is the aim of the paper to optimize the design of 1:2 Y-branch splitter optical waveguide through simulation by using FD-BPM. Y-branch splitter without taper are simulated to optimize the power loss. Width of waveguide and effective angle are manipulated in the power loss optimization. The result shows that evanescent field is maximized at optimized thickness and width. The result suggests that Y-branch splitter with width of 25μm, effective angle of 6.24° is the best design for evanescent field sensor application with both high sensitivity and signal to noise ratio.

scholarly journals Technical Note: Determining regions of interest for CCD camera-based fiber optic luminescence dosimetry by examining signal-to-noise ratio

2011 ◽  
Vol 38 (3) ◽  
pp. 1374-1377 ◽  
Author(s):  
David M. Klein ◽  
Francois Therriault-Proulx ◽  
Louis Archambault ◽  
Tina M. Briere ◽  
Luc Beaulieu ◽  
...  
Keyword(s):  
Fiber Optic ◽  
Signal To Noise Ratio ◽  
Ccd Camera ◽  
Technical Note ◽  
Regions Of Interest ◽  
Signal To Noise ◽  
Luminescence Dosimetry ◽  
Noise Ratio

scholarly journals Evaluation of Measurement Sites for Noninvasive Blood Glucose Sensing with Near-Infrared Transmission Spectroscopy

1999 ◽  
Vol 45 (9) ◽  
pp. 1621-1627 ◽  
Author(s):  
Jason J Burmeister ◽  
Mark A Arnold
Keyword(s):  
Blood Glucose ◽  
Body Fat ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Glucose Sensing ◽  
Infrared Transmission ◽  
Signal To Noise ◽  
Lower Lip ◽  
Percentage Of Body Fat ◽  
Noise Ratio

Abstract Six putative measurement sites were evaluated for noninvasive sensing of blood glucose by first-overtone near-infrared spectroscopy. The cheek, lower lip, upper lip, nasal septum, tongue, and webbing tissue between the thumb and forefinger were examined. These sites were evaluated on the basis of their chemical and physical properties as they pertain to the noninvasive measurement of glucose. Critical features included the effective optical pathlength of aqueous material within the tissue and the percentage of body fat within the optical path. Aqueous optical paths of 5 mm are required to measure clinically relevant concentrations of glucose in the first-overtone region. All of the tested sites met this requirement. The percentage of body fat affects the signal-to-noise ratio of the measurement and must be minimized for reliable glucose sensing. The webbing tissue contains a considerable amount of fat tissue and is clearly the worse measurement site. All other sites possess substantially less fat, with the least amount of fat in tongue tissue. For this reason, the tongue provides spectra with the highest signal-to-noise ratio and is, therefore, the site of choice on the basis of spectral quality.

Bioapplications and biotechnologies of upconversion nanoparticle-based nanosensors

The Analyst ◽  
2016 ◽  
Vol 141 (12) ◽  
pp. 3601-3620 ◽  
Author(s):  
Chengli Wang ◽  
Xiaomin Li ◽  
Fan Zhang
Keyword(s):  
Optical Properties ◽  
High Resistance ◽  
Near Infrared ◽  
Signal To Noise Ratio ◽  
Upconversion Nanoparticles ◽  
Signal To Noise ◽  
Noise Ratio ◽  
Auto Fluorescence ◽  
New Generation ◽  
Narrow Emission

Upconversion nanoparticles (UCNPs), which can emit ultraviolet/visible (UV/Vis) light under near-infrared (NIR) excitation, are regarded as a new generation of nanoprobes because of their unique optical properties, including a virtually zero auto-fluorescence background for the improved signal-to-noise ratio, narrow emission bandwidths and high resistance to photo-bleaching.

Near-infrared absorption fiber-optic sensors for ultra-sensitive CO2detection

2015 ◽  
Author(s):  
Xinyuan Chong ◽  
Ki-Joong Kim ◽  
Paul R. Ohodnicki ◽  
Chih-Hung Chang ◽  
Alan X. Wang
Keyword(s):  
Infrared Absorption ◽  
Near Infrared ◽  
Fiber Optic ◽  
Fiber Optic Sensors
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