The Fiber Optics Illustrated Dictionary - Part 41 fills a gap in the literature by providing instructors, hobbyists, and top-level engineers with an accessible, current reference. From the author of the best-selling Telecommunications Illustrated Dictionary, this comprehensive reference includes fundamental physics, basic technical information for fiber splicing, installation, maintenance, and repair, and follow-up information for communications and other professionals using fiber optic components. Well-balanced, well-researched, and extensively cross-referenced, it also includes hundreds of photographs, charts, and diagrams that clarify the more complex ideas and put simpler ideas into their applications context | Fiber Optics Illustrated Dictionary GAC See Global Area Coverage. gadolinium A light silvery crystallizing ferromagnetic rare earth metal isolated from yttrium in the late 1800s. Gadolinium has been used in the production of phosphors in color cathode-ray tubes CRTs and for making gadolinium yttrium garnets used in microwave technologies. See europium yttrium. gaff The spike that is attached to a utility pole climber s iron. See boomer. gage Performance indicator. See gauge. Gaia Global Astrometric Interferometer for Astrophysics. See interferometer. gain Increase in power of a transmission usually indicated in decibels dB when applied to audio gain. Gain is sometimes intentionally created by using various means to boost a signal. Unfortunately doing so typically also increases noise and interference in analog systems. Gain is descriptive of an antenna s capability to increase its effective radiated signal relative to a reference like an isotropic antenna or a center-fed half-wave dipole antenna. galena A bluish-gray lead sulphide mineral commonly used as a sensitive radio wave detector in crystal detectors in the early 1900s. Sometimes the galena was thinly coated with other materials to improve its properties. gallium arsenide GaAs. A semiconductor substance used to produce electronic components such as computer chips and solar panels when combined with germanium . It is sometimes used in place of silicon for high speed devices. It withstands heat and radiation well making it suitable for orbiting satellite applications. If used alone the bandgap of GaAs is too high for use as semiconductor lasers so the material is impregnated doped with other chemical elements and as such is the main active material used to fabricate semiconductor diode lasers emitting pulsed light in the infrared frequency spectrum. GaAs lasers can be used at room temperature and cooler temperatures and in general emit higher wavelengths at higher temperatures. GaAs lasers emit a wider more .
