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Fiber Optics
Preface
Fiber optics is an emerging form of technology that uses miniature fiber of glass or plastic to transmit light. The light source and method of delivery can be modified to transmit computer data, such as images and sound, or simply luminous light. In recent years, the development of fiber optic technology has increased greatly. Many of these improvements, along with an justification of the technology and social implications will be discussed within this essay.
Introduction
Figure1 Fiber Structure
Fiber optics is a method used to transmit information by means of light pulses along very fine fiber of glass or plastic. Plastic is not commonly used due to it's incapability for extreme pureness. Optical fiber comprise of a glass core, approximately fifty micrometers in diameter, surrounded by a glass "optical cladding" giving an outside diameter of about 120 micrometers. See Figure1 for an overview of an optical fiber.
Total Internal Reflection
Optical fiber depend on Total Internal Reflection (TIR) to achieve reliable results through minimal light loss. If TIR did not occur, light loss would quickly result in signal loss and optical fiber would have the capability to carry signals only a few feet rather than many miles. The angle eA in Figure2 is called the Acceptance Angle. Any light entering the fiber at less than this angle will meet the cladding at an angle greater than eC. If light meets the inner surface of the cladding (the core-cladding interface) at greater than or equal to eC, TIR occurs. All the energy in the ray of light is thus reflected back into the core and none escapes into the cladding. The ray then crosses to the other side of the core, and because the fiber is more or less straight, the ray will meet the cladding at an angle which causes TIR to again occur. This pattern continues until the ray meets the end of the fiber.
History
Figure2 Propagation of Light in a Fiber
The development of fiber...