Conrad L. Young’s Wired Broadband and Related Industry Glossary of Terms with Acronyms As of 15 February 2012 Open Access This document is distributed under the terms of the Creative Commons Attribution Noncommercial License which permits any noncommercial
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- Other Laser-active Dopants in YAG
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Properties of Nd:YAGNd:YAG is a four-level gain medium (except for the 946-nm transition as discussed below), offering substantial laser gain even for moderate excitation levels and pump intensities. The gain bandwidth is relatively small, but this allows for a high gain efficiency and thus low threshold pump power. Nd:YAG lasers can be diode pumped or lamp pumped. Lamp pumping is possible due to the broadband pump absorption mainly in the 800-nm region and the four-level characteristics. 
Energy level structure and common pump and laser transitions of the trivalent neodymium ion in Nd3+:YAG The most common Nd:YAG emission wavelength is 1064 nm. Starting with that wavelength, outputs at 532, 355 and 266 nm can be generated by frequency doubling, frequency tripling and frequency quadrupling, respectively. Other emission lines are at 946, 1123, 1319, 1338 and 1444 nm. When used at the 946-nm transition, Nd:YAG is a quasi-three-level gain medium, requiring significantly higher pump intensities. Nd:YAG is usually used in monocrystalline form, fabricated with the Czochralski growth method, but there is also ceramic (polycrystalline) Nd:YAG available in high quality and in large sizes. For both monocrystalline and ceramic Nd:YAG, absorption and scattering losses within the length of a laser crystal are normally negligible, even for relatively long crystals. Typical neodymium doping concentrations are of the order of 1 at. %. High doping concentrations can be advantageous e.g. because they reduce the pump absorption length, but too high concentrations lead to quenching of the upper-state lifetime via upconversion processes. Also, the density of dissipated power can become too high in high-power lasers. Note that the neodymium doping density does not necessarily have to be the same in all parts; there are composite laser crystals with doped and undoped parts, or with parts having different doping densities. Other Laser-active Dopants in YAGIn addition to Nd:YAG, there are several YAG gain media with other laser-active dopants:
Neodymium- or ytterbium-doped YAG lasers in the 1-μm region in conjunction with frequency doublers are often the basis of green lasers, particularly when high powers are required. (Encylopedia of Laser Physics and Technology) Bibliography
Yagi Antenna A directional antenna array usually consisting of one driven one-half wavelength dipole section, one parasitically excited reflector, and one or more parasitically excited directors mounted in a single plane. (Arris Glossary of Terms) Z: Zener Diode A silicon semiconductor device used as a voltage regulator because of its ability to maintain an almost constant voltage with a wide range of currents. Named after Clarence Melvin Zener (1905-1993), American physicist. Read more: http://www.answers.com/topic/zener-diode#ixzz1K34w3alz (Answers dot com) 
Zener Diode Symbol courtesy of Blogspot Zero Cells A phenomenon common to local market cable television ratings. The Nielsen household meter indicates viewing, but the corresponding diary data shows no record of viewing. Zero-dispersion Slope In single-mode fiber, the rate of change of dispersion with respect to wavelength, at the fiber’s zero-dispersion wavelength. (FiberOpticsInfo)
In a single-mode optical fiber, the wavelength at which material dispersion and waveguide dispersion cancel one another. The wavelength of maximum bandwidth in the fiber. Also called zero-dispersion point. (FiberOpticsInfo) Zero Span A common feature of RF Spectrum Analyzers that allows users to view an incoming signal with a power vs. time display instead of power vs. frequency. (NationalInstruments, NI Developer Zone) Zigbee A specification for wireless personal area networks (WPANs) operating at 868 MHz, 902-928 MHz, and 2.4 GHz. A WPAN is a personal area network (a network for interconnecting an individual's devices) in which the device connections are wireless. Using ZigBee, devices in a WPAN can communicate at speeds of up to 250 Kbps while physically separated by distances of up to 50 meters in typical circumstances and greater distances in an ideal environment. ZigBee is based on the 802.15 specification approved by the Institute of Electrical and Electronics Engineers Standards Association (IEEE-SA). ZigBee provides for high data throughput in applications where the duty cycle is low. This makes ZigBee ideal for home, business, and industrial automation where control devices and sensors are commonly used. Such devices operate at low power levels, and this, in conjunction with their low duty cycle (typically 0.1 percent or less), translates into long battery life. Applications well suited to ZigBee include heating, ventilation, and air conditioning (HVAC), lighting systems, intrusion detection, fire sensing, and the detection and notification of unusual occurrences. ZigBee is compatible with most topologies including peer-to-peer, star network, and mesh networks, and can handle up to 255 devices in a single WPAN. (Search Mobile Computing) Zipcord A two-fiber cable consisting of two single fiber cables having conjoined jackets. A zipcord cable can be easily divided by slitting and pulling the conjoined jackets apart. (FiberOpticsInfo) 
Zipcord Diagram courtesy of Fiber Optics Info dot com, http://www.fiber-optics.info/fiber_optic_glossary/z
BibliographyAmerican National Standards Institute (ANSI) ANSI C63.4, 2003-2009 Methods of Measurement of Radio-Noise Emissions from Low-Voltage Electrical and Electronic Equipment in the Range of 9 kHz to 40 GHz ANSI/SCTE 01 2006 - Specification for “F” Port, Female, Outdoor ANSI/SCTE 02 2006 - Specification for “F” Port, Female, Indoor ANSI/SCTE 81 2007 - Surge Withstand Test Procedure ANSI/SCTE 96 2008 - Cable Telecommunications Testing Guidelines ANSI/SCTE 119 2006 - Measurement Procedure for Noise Power Ratio
http://www.cablelabs.com/news/acronyms/ http://www.cablelabs.com/news/glossary/
IEEE C62.41-1991, IEEE Recommended Practice for Surge Voltages in Low-Voltage AC Power Circuits IEEE Standard 802.3-2008, Carrier sense multiple access with Collision Detection (CSMA/CD) Access Method and Physical Layer Specifications (Includes the EPON standard). See also subsequent corrigenda. IEEE Standard 802.3av-2009, IEEE Standard for Information Technology-Part 3: Amendment 1: Physical Layer Specifications and Management Parameters for 10Gb/s Passive Optical Networks, October 2009 ITU ITU-T G.652d, Characteristics of a Single-Mode Optical Fibre Cable ITU-T G.984, Gigabit-capable passive optical networks (GPON) ITU-T G.987, 10-Gigabit-capable passive optical network (XG-PON) systems ITU-T G.652, Characteristics of a single-mode optical fibre cable ITU-T G.657, Characteristics of a bend-loss insensitive single-mode optical fibre and cable for the access network Multimedia over Coax Alliance (MoCA), http://www.mocalliance.org Society of Cable Telecommunications Engineers (SCTE) http://www.scte.org/standards/Standards_Available.aspx SCTE 174 2010 Radio Frequency over Glass Fiber-to-the-Home Specification
47CFR15.109: 2005 Radio Frequency Devices, Unintentional Radiators, Radiated Emission Limits 47CFR76.605 (12) 2004, Code of Federal Regulations, Multichannel Video and Cable Television Service, Technical Standards 47CFR76.609 (h): 1993 Code of Federal Regulations, Multichannel Video and Cable Television Service, Measurements 47CFR76.614: 2000 Code of Federal Regulations, Multichannel Video and Cable Television Service, Cable Television System regular monitoring
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