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Thursday, April 29, 2010

Fiber optic network

Fiber optic network

Optical fiber can be used as a medium for telecommunication and networking because it is flexible and can be bundled as cables. It is especially advantageous for long-distance communications, because light propagates through the fiber with little attenuation compared to electrical cables. This allows long distances to be spanned with few repeaters. Additionally, the per-channel light signals propagating in the fiber have been modulated at rates as high as 111 gigabits per second by NTT although 10 or 40 Gb/s is typical in deployed systems. Each fiber can carry many independent channels, each using a different wavelength of light (wavelength-division multiplexing (WDM)). The net data rate (data rate without overhead bytes) per fiber is the per-channel data rate reduced by the FEC overhead, multiplied by the number of channels (usually up to eighty in commercial dense WDM systems as of 2008). The current laboratory fiber optic data rate record, held by Bell Labs in Villarceaux, France, is multiplexing 155 channels, each carrying 100 Gb/s over a 7000 km fiber.[19] Nippon Telegraph and Telephone Corporation have also managed 69.1 Tb/s over a single 240km fibre (multiplexing 432 channels, equating to 171 Gb/s per channel). Bell Labs also broke a 100 Petabit per second kilometer barrier

Fiber optic cable

Fiber optic cable
Light is kept in the core of the optical fiber by total internal reflection. This causes the fiber to act as a waveguide. Fibers which support many propagation paths or transverse modes are called multi-mode fibers (MMF), while those which can only support a single mode are called single-mode fibers (SMF). Multi-mode fibers generally have a larger core diameter, and are used for short-distance communication links and for applications where high power must be transmitted. Single-mode fibers are used for most communication links longer than 550 meters (1,800 ft).
Joining lengths of optical fiber is more complex than joining electrical wire or cable. The ends of the fibers must be carefully cleaved, and then spliced together either mechanically or by fusing them together with an electric arc. Special connectors are used to make removable connections.
Cable jetting
Data cable
Fiber Bragg grating
Glass transition
Gradient-index optics
Leaky mode
Light Peak
Optical communication
Optical fiber connector
Physics of glass
Small form-factor pluggable transceiver
Strength of glass
Submarine communications cables
Transparency and translucency
vector soliton
fiber laser

Fiber cable

Fiber cable
An optical fiber is made up of the core(carrying the light pulses), the cladding (reflecting the light pulses back into the core) and the buffer coating (protecting the core and cladding from moisture, damage etc.). Together, all of this creates a fiber optic which can carry up to 10 million messages at any time using light pulses. Fiber optics is the overlap of applied science and engineering concerned with the design and application of optical fibers. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher bandwidths (data rates) than other forms of communications. Fibers are used instead of metal wires because signals travel along them with less loss, and they are also immune to electromagnetic interference. Fibers are also used for illumination, and are wrapped in bundles so they can be used to carry images, thus allowing viewing in tight spaces. Specially designed fibers are used for a variety of other applications, including sensors and fiber lasers.

Fiber optic patch cable

Fiber optic patch cable
OFC: Optical fiber, conductive
OFN: Optical fiber, nonconductive
OFCG: Optical fiber, conductive, general use
OFNG: Optical fiber, nonconductive, general use
OFCP: Optical fiber, conductive, plenum
OFNP: Optical fiber, nonconductive, plenum
OFCR: Optical fiber, conductive, riser
OFNR: Optical fiber, nonconductive, riser
OPGW: Optical fiber composite overhead ground wire

Fiber patch cables

fiber patch cables
An optical fiber cable is a cable containing one or more optical fibers. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed. Patch cords
The buffer or jacket on patchcords is often color-coded to indicate the type of fiber used. The strain relief "boot" that protects the fiber from bending at a connector is color-coded to indicate the type of connection. Connectors with a plastic shell (such as SC connectors) typically use a color-coded shell. Standard color codings for jackets and boots (or connector shells) are shown below:

Host Apparel Garment

Apparel Garment host
American Apparel is the largest clothing manufacturer in the United States.[4] It is a vertically integrated clothing manufacturer, wholesaler, and retailer that also performs its own design, advertising, and marketing. It is best-known for making basic cotton knitwear such as T-shirts and underwear, but in recent years it has expanded - to include leggings, leotards, tank tops, vintage clothing, dresses, pants, denim, bedding and accessories for men, women, children, babies and dogs.