What characteristics of single mode fiber optics?

Answer 1

Optical Fibres are tiny cylindrical strands of glass that carry light rather than electrical energy. Fiber-optic cable is increasingly used for long-distance phone lines because it can carry large amounts of data, is not subject to crosstalk or electromagnetic noise, and cannot be tapped into without producing a noticeable drop in signal level.

* Glass and/or plastic cables connect to a light source and the light is carried from the source through the cable by a reflected inner lining. The diameter of the cables vary in milimeters and if bent sharply can break the integrity of the cable and diminish the light source. The cables can be cut to various lengths and the tips where the light comes out does not get hot. * Fiber Optic Fibers have been around for more then forty years, and since then they have become more cost effective and stronger. Plastic fibers are made with chemicals, the CORE is Polymethyl Methacrylate polymer (PMMA), and the CLAD is a thin layer of Fluorine polymer. The Core carries the light down the Fiber while the Clad is the reflective surface the light bounces off of! The diagram below shows what happens to light as it enters and travels through the fiber. Light enters through one end of the fiber and is "Reflected" to the other end, if the angle of the light is to great the light will not enter the fiber correctly and refraction will be lost. Skewed fiber is when the ends are not cut parallel to the 90-degree axis of the fiber. Light is also lost if the ends are not polished; to polish the ends of fiber you can use a 600 grit wet-dry sandpaper and finish with a 3m polishing film or a 1500 or greater sandpaper. The fiber has a 17% Clad which doesn't carry light, so the transmission of a one foot piece of fiber is in the area of 60-65%. * If light enters one end of a fiber, it will travel through the fiber with very low loss, even if the fiber is curved. The principle that makes this transmission of light work depends on the total of internal reflection. The light traveling inside the fiber center, or core, strikes the outside surface at an angle greater than the critical angle, so that all the light is reflected toward the inside of the fiber without loss. This allows the light to be transmitted over long distances by being reflected inward thousands of times. To keep the light from loosing its power and to avoid losses through the scattering of light by impurities on the surface of the fiber, the optical fiber core is covered or (clad) with a glass (or plastic) layer of a much lower refractive index; the reflections occur at the interface of the glass fiber and the cladding. * Tiny cylindrical strands of glass that carry light rather than electrical energy. Fiber-optic cable is increasingly used for long-distance phone lines because it can carry large amounts of data, is not subject to crosstalk or electromagnetic noise, and cannot be tapped into without producing a noticeable drop in signal level.

Answer 2

Singlemode fiber shrinks the core down so small that the light can only travel in one ray. This increases the bandwidth to almost infinity - but it's practically limited to about 100,000 gigahertz - that's still a lot!