Overtone vibrations of OH groups in fused silica optical fibers

1982 ◽  
Vol 76 (4) ◽  
pp. 1712-1722 ◽  
Author(s):  
J. Stone ◽  
G. E. Walrafen
Keyword(s):  
Optical Fibers ◽  
Fused Silica ◽  
Oh Groups

Mechanical Properties of SiO2 vs. SiO2-TiO2 Bulk Glasses and Fibers

1991 ◽  
Vol 244 ◽  
Author(s):  
Suresh T. Gulati
Keyword(s):  
Mechanical Properties ◽  
Optical Fibers ◽  
Mechanical Performance ◽  
Fatigue Behavior ◽  
Deformation Mode ◽  
Strength Distribution ◽  
Fused Silica ◽  
Space Applications ◽  
Silica Glasses ◽  
Silica And Titania

ABSTRACTThe mechanical properties of silica and titania-doped silica glasses, in bulk and fiber forms, are presented. These include the elastic properties (E and ν), strength distribution (in tension and bending), fatigue behavior (dynamic and static loading) and fracture toughness. Following a brief review of above properties for fused silica and ULE™ glasses (Coming Codes 7940 and 7971), used primarily for space applications, the mechanical properties data for silica and titania-doped silica-clad optical fibers are presented. The enhancement of mechanical performance of titania-doped silica clad fiber is also discussed.The effect of titania doping on fundamental properties like stress-free activation energy, crack tip pH, and deformation mode of Si-O-Si bond is discussed. In addition, the crack velocity data obtained from DCDC specimens of homogeneous silica and titania-doped silica glasses are compared in an attempt to understand the role titania plays in improving the fatigue resistance of optical fibers.

A Step-Index Multimode Fiber-Optic Microbend Displacement Sensor Wavelength Dependent Loss

2019 ◽  
pp. 47-60
Author(s):  
Sami D. Alaruri
Keyword(s):  
Optical Fibers ◽  
Fiber Optic ◽  
Transmission Loss ◽  
Wavelength Dependence ◽  
Fiber Optic Sensors ◽  
Fused Silica ◽  
Displacement Sensor ◽  
Sensor Output ◽  
Core Diameter ◽  
Step Index

In this chapter, the wavelength dependence of bend loss in a step-index multimode optical fiber (100 µm core diameter; fused silica) was investigated for fiber bend radii ranging between 2.0 and 4.5 mm using six laser excitation wavelengths, namely, 337.1, 470, 590, 632.8, 750, and 810 nm. The results obtained from fitting the bend loss measurements to Kao's model and utilizing MATLAB® indicate that bend loss is wavelength dependent and transmission loss in multimode optical fibers increases with the decrease in the fiber bend radius. Furthermore, the response of a microbend fiber-optic displacement sensor was characterized at 337.1, 470, 632.8, 750, and 810 nm. Measurements obtained from the microbend sensor indicate that the sensor output power is linear with the applied displacement and the sensor output is wavelength dependent. Lastly, references for industrial and biomedical applications of microbend fiber-optic sensors are provided. Finally, a brief description for the transmission loss mechanisms in optical fibers is given.

Activation Energy for Strength Degradation of Fused Silica Optical Fibers

1998 ◽  
Vol 531 ◽  
Author(s):  
Yunn-Shin Shiue ◽  
M. John Matthewson
Keyword(s):  
Activation Energy ◽  
Optical Fibers ◽  
Pure Water ◽  
Strength Degradation ◽  
Fused Silica ◽  
Static Fatigue ◽  
Buffer Solution ◽  
Silica Fibers ◽  
Apparent Activation Energies ◽  
Stress Dependent

AbstractThe strength degradation behavior of fused silica optical fiber is well known to be sensitive to the temperature and an apparent activation energy can be determined. In addition, it has been observed that the activation energy also depends on the applied stress and the nature of the environment. However, no consistent model for this behavior has emerged. We propose a chemical kinetics model which accounts for the temperature dependence of the dissociation of water which predicts that degradation should be faster in pH 7 buffer than in pure water. Static fatigue of fused silica fibers in both water and pH 7 buffer solution has been carefully studied as a function of temperature to test the model. The apparent activation energies are stress dependent, and, while the dependency is not clear, different environments give different dependencies. These observations support the proposed model.

Thermal Radiative Properties of a Semitransparent Fiber Coated With a Thin Absorbing Film

2006 ◽  
Vol 129 (6) ◽  
pp. 763-767 ◽  
Author(s):  
Weixue Tian ◽  
Wei Huang ◽  
Wilson K. S. Chiu
Keyword(s):  
Thin Film ◽  
Optical Fibers ◽  
Fiber Surface ◽  
Chemical Vapor ◽  
Fused Silica ◽  
Radiative Properties ◽  
Thermal Radiative Properties ◽  
Proposed Model ◽  
Transport Analysis ◽  
Fiber Radius

This study presents the hemispherical model to predict the hemispherical total thermal radiative properties of a fiber coated with a thin film. The fiber is composed of semi-transparent media, such as fused silica. The film is made of strong absorbing media with thickness on the order of tens of nanometers. The film is assumed to be “locally flat” at the point of incidence for radiative transfer analysis because the thickness of the film is much less than the fiber radius. Wave optics is employed to calculate the reflectance and transmittance of the thin film while the ray tracing method is used for radiative transport analysis of the fiber. Effects of film and fiber substrate optical properties, film thickness and temperature on predicted thermal radiative properties are investigated. One of the applications of the proposed model is for studying the chemical vapor deposition of hermetic coatings on optical fibers, in which the thermal radiative properties of the fiber–film system heavily influence the fiber surface temperature and chemical reaction rate.

Biomimetic model of a sponge-spicular optical fiber—mechanical properties and structure

2001 ◽  
Vol 16 (5) ◽  
pp. 1420-1428 ◽  
Author(s):  
M. Sarikaya ◽  
H. Fong ◽  
N. Sunderland ◽  
B. D. Flinn ◽  
G. Mayer ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Optical Fibers ◽  
Circular Cross Section ◽  
Fused Silica ◽  
Atomic Force ◽  
Commercial Glass ◽  
Bend Tests ◽  
Point Bend ◽  
Thick Layers

Nanomechanical properties, nanohardness and elastic modulus, of an Antarctic sponge Rosella racovitzea were determined by using a vertical indentation system attached to an atomic force microscope. The Rosella spicules, known to have optical waveguide properties, are 10–20 cm long with a circular cross section of diameter 200–600 μm. The spicules are composed of 2–10-μm-thick layers of siliceous material that has no detectable crystallinity. Measurements through the thickness of the spicules indicated uniform properties regardless of layering. Both the elastic modulus and nanohardness values of the spicules are about half of that of either fused silica or commercial glass optical fibers. The fracture strength and fracture energy of the spicules, determined by 3-point bend tests, are several times those of silica rods of similar diameter. These sponge spicules are highly flexible and tough possibly because of their layered structure and hydrated nature of the silica. The spicules offer bioinspired lessons for potential biomimetic design of optical fibers with long-term durability that could potentially be fabricated at room temperature in aqueous solutions.

Real-Time Investigation of Thermal Poling Process in Optic Fiber

2013 ◽  
Vol 321-324 ◽  
pp. 453-459
Author(s):  
Jian He ◽  
Zhe Chen ◽  
Yun Han Luo
Keyword(s):  
Real Time ◽  
Optical Fibers ◽  
Processing Parameters ◽  
Test System ◽  
Fused Silica ◽  
Thermal Poling ◽  
Poling Process ◽  
High Voltage Breakdown ◽  
Time Test ◽  
Poling Voltage

Thermal poling could make centrosymmetric fused silica optical fibers generate second-order nonlinearity effect and linear electooptic effect. In order to investigate the influence of thermal poling parameters on linear electooptic effect, a real-time test system, which mainly consists of an all polarization maintaining fiber Mach-Zehnder interferometer, has been utilized to monitor the whole thermal poling process in fibers. The processing parameters in thermal poling, such as applied poling voltage, poling duration and temperature, have been measured in real time. Based on those measurements, their influence on the linear electrooptic effect has been discussed. Experiment results show that the linear electrooptic coefficient would increase when a stronger electric field is applied on fibers. Considering the anti-high-voltage breakdown capability of fibers, a DC voltage from 3KV to 4KV is suitable for polarization in thermal poling. When using 3KV, the optimum poling duration is about 16 minutes and the best temperature for thermal poling is around 190°C. Keywords: electro-optic effect, poled fiber, thermal poling, real time test system, fiber optic interferometer

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