No wonder Fios has been rated 1 by industry leaders time and again. Shop for Verizon Fios and see if fiber internet is available in your area. Get Fios. Speeds up to Mbps download and Mbps upload available in select areas. Broadband is the transmission of wide bandwidth data over a high speed internet connection.
The maximum amount of data transmitted over an internet connection in a given amount of time. Fiber optics Definition Fiber optics is the technology used to transmit information as pulses of light through strands of fiber made of glass or plastic over long distances. Fiber-optic cables A fiber-optic cable contains anywhere from a few to hundreds of optical fibers within a plastic casing. More protection is provided by the "cable" which has the fibers and strength members inside an outer protective covering called a "jacket".
Also see FOA Lecture 60 How Fiber Works video Fiber Trivia Although glass optical fibers are made of a material that everyone assumes is fragile, it's ultra pure glass is actually quite flexible and 3 times stronger than steel and 6 times stronger than titanium according to the largest manufacturer of optical fiber, Corning.
Most glass fibers are microns in outside diameter - a micron is one one-millionth of a meter and microns is 0. Multimode fiber has light traveling in the core in many rays, called modes. It has a larger core almost always 50 or Multimode is generally used with LED sources at wavelengths of and nm see below! Singlemode fiber has a much smaller core, only about 9 microns, so that the light travels in only one ray mode. It is used for telephony and CATV with laser sources at and nm because it has lower loss and virtually infinite bandwidth.
Fiber is filled with jargon that is traditional and often obtuse in meaning. Plastic Optical Fiber POF is large core about 1mm fiber, usually step index, that is used for short, low speed networks. Fiber types. The right part of the drawing shows the index profile of the fiber.
The index profile shows the relative index of refraction of the material used in making the fiber. Total Internal Reflection The index of refraction of glass or any optical material is a measure of the speed of light in the material and changes in index of refraction are what causes light to bend - as shown in this photo of a plastic rod in a pond: Beyond a certain angle, the refraction will cause light to be reflected from the surface.
Optical fiber uses this reflection to "trap" fiber in the core of the fiber by choosing core and cladding materials with the proper index of refraction that will cause all the light to be reflected if the angle of the light is below a certain angle.
We call that "total internal reflection. At higher angles a ray of light will be refracted but not enough so it is lost in the cladding of the fiber. Below that angle, it will be reflected back into the core of the fiber and transmitted to the end of the fiber. The angle of total internal reflection defines the "numerical aperture" NA of the fiber, a standard fiber specification.
More about total internal reflection in optical fiber. Step Index Multimode Fiber Step index multimode fiber was the first fiber design. Graded Index Multimode Fiber Graded index multimode fiber uses variations in the composition of the glass in the core to compensate for the different path lengths of the modes.
Graded index GI fiber is made with a range of materials in the core which are chosen to minimize modal dispersion caused by different path lengths of different modes being transmitted down the fiber. The core index profile is curved - a parabola to be exact - with lower index glass on the outside of the core.
The lower index glass transmits the higher angle light rays called high order modes faster than the lower index glass near the center of the core. The index profile of the core of multimode GI fiber is not continuous, which is hard if not impossible to manufacture, but is in steps, from hundreds of steps to thousands depending on the fiber design and manufacturing process.
As a mode of light goes through each step, it is bent slightly until it is reflected back toward the core of the fiber. It can range from a single fiber to many hundreds. Improve this answer.
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