Near infrared radio-luminescence of O2 loaded radiation hardened silica optical fibers: A candidate dosimeter for harsh environments

2014 ◽  
Vol 105 (18) ◽  
pp. 183508 ◽  
Author(s):  
D. Di Francesca ◽  
S. Girard ◽  
S. Agnello ◽  
C. Marcandella ◽  
P. Paillet ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Near Infrared ◽  
Harsh Environments ◽  
Radiation Hardened

In situ near infrared evanescent wave examination of surfactant adsorption on silica optical fibers

1994 ◽  
Vol 2 (3) ◽  
pp. 187-197 ◽  
Author(s):  
A.K. Liao ◽  
W.M. Cross ◽  
R.M. Winter ◽  
J.J. Kellar
Keyword(s):  
Optical Fibers ◽  
Evanescent Wave ◽  
Near Infrared ◽  
Surfactant Adsorption

Expanded Beam Fiber Optic Connectors Increase Optical Link Margin

2015 ◽  
Vol 2015 (1) ◽  
pp. 000609-000615 ◽  
Author(s):  
John Mazurowski
Keyword(s):  
Optical Fibers ◽  
High Speed ◽  
Fiber Optic ◽  
Physical Contact ◽  
Harsh Environments ◽  
Multimode Fiber ◽  
Optical Signals ◽  
Optical Link ◽  
Link Margin ◽  
Temperature Ranges

Present fiber optic connections need to align two or more optical fibers to accuracies of microns (multimode fiber) and tenths of a micron (single more fiber). For connections in rugged applications, consisting of wide temperature ranges, substantial vibration, or in the presence of contaminants, the alignment of normal physical contact connections becomes even more difficult. New expanded beam connectors make fiber optic connections more durable, and help stabilize the transmission of high speed optical signals between systems, boxes, boards, and devices in these harsh environments.

Radiation Effects on Aluminosilicate Optical Fibers: Spectral Investigations From the Ultraviolet to Near‐Infrared Domains

2018 ◽  
Vol 216 (3) ◽  
pp. 1800485 ◽  
Author(s):  
Antonino Alessi ◽  
Angela Guttilla ◽  
Sylvain Girard ◽  
Simonpietro Agnello ◽  
Marco Cannas ◽  
...  
Keyword(s):  
Optical Fibers ◽  
Radiation Effects ◽  
Near Infrared

Near-Infrared Raman Spectrometer Systems for Human Tissue Studies

1997 ◽  
Vol 51 (2) ◽  
pp. 201-208 ◽  
Author(s):  
James F. Brennan ◽  
Yang Wang ◽  
Ramachandra R. Dasari ◽  
Michael S. Feld
Keyword(s):  
Optical Fibers ◽  
Background Subtraction ◽  
System Performance ◽  
Near Infrared ◽  
Clinical Use ◽  
Human Tissues ◽  
Laboratory Measurements ◽  
Spectroscopy Studies ◽  
Clinical Systems ◽  
Large Background

We have built two types of instruments for near-infrared Raman spectroscopy studies of human tissues, one for laboratory measurements and one for clinical use. The laboratory systems are designed to collect the highest quality spectra possible and allow different excitation/collection wavelengths to be studied. The clinical systems are designed to collect spectra via optical fibers within a few seconds and to be mobile and hospital-compatible. These systems are capable of detecting weak near-infrared Raman bands hidden in large background signals. Calibration and background subtraction procedures are described, and system performance is evaluated.

Spatial heterogeneity of quadriceps muscle deoxygenation kinetics during cycle exercise

2007 ◽  
Vol 103 (6) ◽  
pp. 2049-2056 ◽  
Author(s):  
Shunsaku Koga ◽  
David C. Poole ◽  
Leonard F. Ferreira ◽  
Brian J. Whipp ◽  
Narihiko Kondo ◽  
...  
Keyword(s):  
Spatial Heterogeneity ◽  
Optical Fibers ◽  
Near Infrared ◽  
Quadriceps Muscle ◽  
Primary Component ◽  
Phase 2 ◽  
Cycle Exercise ◽  
Muscle Deoxygenation ◽  
Spatially Inhomogeneous ◽  
Exercise Onset

To test the hypothesis that, during exercise, substantial heterogeneity of muscle hemoglobin and myoglobin deoxygenation [deoxy(Hb + Mb)] dynamics exists and to determine whether such heterogeneity is associated with the speed of pulmonary O2 uptake (pV̇o2) kinetics, we adapted multi-optical fibers near-infrared spectroscopy (NIRS) to characterize the spatial distribution of muscle deoxygenation kinetics at exercise onset. Seven subjects performed cycle exercise transitions from unloaded to moderate [<gas exchange threshold (GET)] and heavy (>GET) work rates and the relative changes in deoxy(Hb + Mb), at 10 sites in the quadriceps, were sampled by NIRS. At exercise onset, the time delays in muscle deoxy(Hb + Mb) were spatially inhomogeneous [intersite coefficient of variation (CV), 3∼56% for <GET, 2∼21% for >GET]. The primary component kinetics (time constant) of muscle deoxy(Hb + Mb) reflecting increased O2 extraction were also spatially inhomogeneous (intersite CV, 6∼48% for <GET, 7∼47% for >GET) and faster (P < 0.05) than those of phase 2 pV̇o2. However, the degree of dynamic intersite heterogeneity in muscle deoxygenation did not correlate significantly with phase 2 pV̇o2 kinetics. In conclusion, the dynamics of quadriceps microvascular oxygenation demonstrates substantial spatial heterogeneity that must arise from disparities in the relative kinetics of V̇o2 and O2 delivery increase across the regions sampled.

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