Optical Fiber Characteristics

Glasses for Light Transmission Fiber Optics 17.3.2.2.1. Optical Fiber Characteristics. 

H. Bauch, V. Paquet, W. Siefert, Preparation of Optical Fiber Performs by Plasma-Impulse-CVD, Proc. SPIE, Vol. 584, Optical Fiber Characteristics and Standards,... 

UE 910 Standardfor Safety, Test Methodfor Fire and Smoke Characteristics of Electrical and Optical Fiber Cables used in Air Handling Spaces, Underwriters Laboratories, Inc. Northbrook, lU., 1985. 

FPN) The characteristics of various atmospheric mixtures of gases, vapors, and dusts depend on the specific material involved. Optical fiber cables and fiber optic devices approved for hazardous (classified) locations shall be installed in accordance with Sections 504-20 and 770-52. 

Okazaki S., Nakagawa H., Asakura S., Tomiuchi Y., Tsuji N., Murayama H., Washiya M., Sensing characteristics of an optical fiber sensor for hydrogen leak, Sensors Actuators B 2003 93 141-147. 

In the passive mode, the optical device measures the variation in fluorescence characteristics (intensity, lifetime, polarization) of an intrinsically fluorescent analyte. The optical device can have different optical configurations involving in most cases an optical fiber (passive optode) (Figure 10.44). 

Instrumentation and methods currently available provide limited means for realtime measurements of the continuous wave (CW) and transient characteristics of luminescent substances. The measurement, in real time, of the spatial distribution of a parameter of interests, for instance, in cells and in tissue cannot be attained with present technology. Optical fibers are used to monitor the response of a sensor in limited regions in space. 

Sensors are usually attached chemically or physically to other materials here referred as the carrier, like polymers, antibodies, and optical fibers in order to facilitate the sensing process. These carriers generally affect the luminescent characteristics of the sensor molecules. The modification of the luminescent characteristics of the sensor is caused by the creation of more than one microphase or microenvironment for the sensor. Each molecule in its particular microenvironment may return to the ground state following a different set of processes or mechanisms. Alternatively, the nonra-diative decay rate of each microphase may be different for each sensor molecule. Depending on the characteristics of the carrier and the sensor, the number of microphases may be one, two, three, or an infinite number. 

Platinum and palladium porphyrins in silicon rubber resins are typical oxygen sensors and carriers, respectively. An analysis of the characteristics of these types of polymer films to sense oxygen is given in Ref. 34. For the sake of simplicity the luminescence decay of most phosphorescence sensors may be fitted to a double exponential function. The first component gives the excited state lifetime of the sensor phosphorescence while the second component, with a zero lifetime, yields the excitation backscatter seen by the detector. The excitation backscatter is usually about three orders of magnitude more intense in small optical fibers (100 than the sensor luminescence. The use of interference filters reduce the excitation substantially but does not eliminate it. The sine and cosine Fourier transforms of/(f) yield the following results ... 

The primary reason for interest in fiber optic sensors, in most cases, stems from the fundamental differences between the use of optical fiber and a metal wire for signal transmission.(2) These differences give fiber optic sensors the following advantageous characteristics. 

Figure 12.8. Transmission characteristics of some commonly used optical fibers, (a) glass fiber (b) gradient-index fiber (c) plastic-clad silica fiber (d) plastic fiber. (Reproduced with permission from the Ealing Corporation.)...

Table 6.29 Comparison of Transmission Characteristics for Copper Wire and Optical Fiber...

The great value of the unique characteristics of fluorinated polymers in the development of modern industries has ensured an increasing technological interest since the discovery of the first fluoropolymer, poly(chlorotrifluoro-ethylene) in 1934. Hence, their fields of applications are numerous paints and coatings [10] (for metals [11], wood and leather [12], stone and optical fibers [13, 14]), textile finishings [15], novel elastomers [5, 6, 8], high performance resins, membranes [16, 17], functional materials (for photoresists and optical fibers), biomaterials [18], and thermostable polymers for aerospace. 

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