Jitney - Low cost optical link.
Jumper Cable - Single fiber optics cable with connectors on both ends.
Kevlar - See Aramid yarn.
Kilo Hertz (KHz) - 1,000 Hz.
Kilometer - 1,000 meters or 3,281 feet. The kilometer is a unit of measurement in fiber optic communications.
KPSI - A unit of tensile strength expressed in 1,000's of pounds per square inch.
LAN - Local Area Network. This is a geographically limited data communications network. It is often referred to as premises data communications network. Its extent is usually limited to the office building, campus or manufacturing plant - several 1,000 feet.
Large core fiber - Usually this refers to fiber optic cable with a core of 200 mm or more. However, sometimes it is applied to 100/140-fiber optic cable.
Laser - An acronym for Light (by) Amplification (by) Stimulated Emission (of ) Radiation. This is a device, which artificially generates coherent light within a narrow range of wavelengths. Lasers can be made to operate in a number of different ways. In one mechanism the molecules of some material are put at higher energy levels. When light is then incident upon the material the molecules make transitions to lower energy levels. The correspondingly released energy is realized as coherent light. Lasers are used as the transmitting source for fiber optic cables when transmission distances are long. Laser light denotes light generated by a laser.
Lateral displacement loss - The loss of power that results from lateral displacement from optimum alignment between 2 fiber optic cables or between a fiber optic cable and an active device.
Launch angle - This term is used in 4 different contexts. First, it often refers to the beam divergence of a light source. Secondly, it refers to as the beam divergence from any emitting surface such as an LED, laser, prism or fiber optic cable end. Thirdly, it refers to the angle at which a light beam emerges from a surface. Fourthly, in a fiber bundle it refers to the angle between the input radiation vector (the chief ray of input light) and the axis of the fiber bundle. In this case if the ends of the fiber optic cables are perpendicular to the axis of the fiber optic cable then the launch angle is equal to the incidence angle when the ray is external and the refraction angle when initially inside the fiber.
Launching fiber - A fiber optic cable used in conjunction with a source to excite the modes of another fiber optic cable in a particular way. Launching fiber optic cables are most often used in test systems to improve the precision of measurements.
Launch Numerical Aperture (LAN) - The numerical aperture of an optical system, which is used to couple (launch) power into a fiber optic cable. LNA may differ from the stated NA of final focusing element if, for example, that element is underfilled or the focus is other than that for which the element is specified. LNA is one of the parameters that determine the initial distribution of power among the modes of a fiber optic cable.
Law of Reflection - Angle of incidence = Angle of reflection.
LD - Laser diode.
LED - Light Emitting Diode.
Light - In the laser and optical communication fields is that portion of the electromagnetic spectrum that can be handled by the basic optical techniques used for the visible spectrum extending from the near ultraviolet region of approximately 0.3 mm through the visible region into the mid-infrared region of approximately 30 mm.
Light Emitting Diode - LED. A semiconductor diode that spontaneously emits light from the pn junction when forward current is applied.
Light piping - Use of fiber optic cables to illuminate.
Light source - Source of light, which is usually modulated and terminated over a fiber optic cable. It is typically an LED or LD.
Lightguide cable - A fiber optic cable or fiber bundle which includes a cable jacket and strength members.
Lightwaves - Electromagnetic waves in the region of optical frequencies. The term light was originally restricted to radiation visible with the human eye, with wavelengths between 400 and 700 nm. However, it has become customary to refer to radiation in the spectral regions adjacent to visible light (in the near infrared from 700 to 2,000 nm) as light in order to emphasize the physical and technical characteristics they have in common with light.
Link - A fiber optic cable with connectors attached to a transmitter (source) and receiver (detector).
LLDPE - Linear low density polyethylene jacketing.
Local Area Network - See LAN.
Loose tube - A protective tube loosely surrounding a fiber optic cable often filled with a water blocking gel.
Loss - Attenuation of optical signal. It is usually measured in dB.
Loss budget - An accounting of overall attenuation in a system.
Low NA - Numerical Aperture around 0.30.
LUCINA™ - Graded indexes CYTOP fiber optic cable (GI-COF) manufactured by Asahi Glass Co.
LUMINOUS® - Trademark of plastic fiber optic cable manufactured by Asahi Chemical.
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