Medical research

How injured nerves stop themselves from healing

Three main causes for the inability of injured nerves of the central nervous system, or CNS, to regenerate have been known to date: the insufficient activation of a regeneration program in injured nerve cells that stimulates ...

Inflammatory disorders

Sensor tracks cortisol levels in real time

Skoltech researchers have developed a prototype of a fluorescence-based sensor for continuous detection of cortisol concentrations in real time, which can help monitor various health conditions. The paper was published in ...

Neuroscience

MicroLED neural probe for neuroscience

Associate Professor Hiroto Sekiguchi and Ph.D. candidate Hiroki Yasunaga in the Department of Electrical and Electronic Information Engineering at Toyohashi University of Technology have developed a MicroLED neural probe ...

Neuroscience

Optical stimulation causes marmosets to move their forelimbs

RIKEN neuroscientists have succeeded in getting marmosets to move their forelimbs when they shine laser light on the motor cortex—the brain region responsible for planning, conducting and controlling voluntary movements. ...

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Optical fiber

An optical fiber (or fibre) is a glass or plastic fiber that carries light along its length. 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.

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 metres (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.

This text uses material from Wikipedia, licensed under CC BY-SA