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Topic: Optical power

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Optical power margin - Wikipedia, the free encyclopedia Optical power margin: In an optical communications link, the difference between (a) the optical power that is launched by a given transmitter into the fiber, less transmission losses from all causes, and (b) the minimum optical power that is required by the receiver for a specified level of performance. Note 2: The amount of optical power launched into a given fiber by a given transmitter depends on the nature of its active optical source (LED or laser diode) and the type of fiber, including such parameters as core diameter and numerical aperture. At least several dB of optical power margin should be included in the optical power budget. www.wikipedia.org /wiki/Optical_power_margin

Definition: optical power budget optical power budget: In a fiber-optic communication link, the allocation of available optical power (launched into a given fiber by a given source) among various loss-producing mechanisms such as launch coupling loss, fiber attenuation, splice losses, and connector losses, in order to ensure that adequate signal strength (optical power) is available at the receiver. Note 2: The amount of optical power launched into a given fiber by a given transmitter depends on the nature of its active optical source (LED or laser diode) and the type of fiber, including such parameters as core diameter and numerical aperture. Manufacturers sometimes specify an optical power budget only for a fiber that is optimum for their equipment--or specify only that their equipment will operate over a given distance, without mentioning the fiber characteristics. www.atis.org /tg2k/_optical_power_budget.html   (260 words)

Optical transmitter power measurement and control - Patent 4991229 About 10% of the power in the optical signal is reflected as shown by light ray C. Light ray D represents an optical signal having a concentration of energy at a second wavelength.lambda..sub.2 generated by an external optical source through another mirror not shown. The transmitter output power control and fault indication system shown comprises a controller 20, an optical detector and low pass filter 30, a WDM 40, a transmitter 50 and a temperature sensor 60. An optical signal, for example, in the form of a light beam having a concentration of energy at a particular wavelength.lambda..sub.1 is transmitted from transmitter 12 onto mirror 14. www.freepatentsonline.com /4991229.html   (260 words)

Wavelength power equalization by attenuation in an optical switch - US Patent 6697547 In conventional implementation, the unattenuated beam B is reflected by the reflectors of a switch such that maximum optical power is transmitted and the beam B is positioned to enter the output fiber in a substantially centered manner. Optical power information received by the detector 136 is supplied to the control circuitry 36 where it is used to determine reflector orientation. In an optical switch the optical power of an optical beam can be depicted as a three-dimensional curve 1100 with the magnitude of optical power on one axis (shown here as the log of optical power along the Z-axis), and reflector parameters or beam position on the other two axes (the X- and Y-axes). www.patentstorm.us /patents/6697547.html   (260 words)

Optical power meter - Patent 5127724 An optical power meter is used to measure the optical power of optical energy passing along an optical fibre (11). The output of the pre-amp 2 then passes to a log-lin converter 3 which linearises the output voltage from the pre-amp (which is directly proportional to the intensity of the optical input) such that the output visual indication is linear with the input optical power (measured in dBm). Conveniently, the driver is calibrated using a known relationship between the amplified electrical signal and the optical power. www.freepatentsonline.com /5127724.html   (260 words)

Lightwave - All-optical switches: the evolution of optical functionality The decrease in optical power doubles at amplifiers 2 and 3, causing a significant decrease in power at the receiver in node F. As a result, a loss-of-service alarm and protection switch may occur. Since optical multicast inherently involves the distribution of the optical power among several client nodes, a power penalty is incurred. For example, the new wavelength between nodes D and G causes an increase in optical power at the input to amplifier 1, resulting in 3-dB less gain to the connected channel. lw.pennnet.com /Articles/Article_Display.cfm?Section=Articles&Subsection=Display&ARTICLE_ID=125387   (2741 words)

IT Architect Managing Fiber Cabling December 4, 2002 To begin an optical power loss measurement (sometimes characterized as "attenuation" or "insertion loss"), connect a light source to an optical power meter with a reference or "launch" cable. The power budget graphs the factors along the length of the cable that contribute to optical power loss. Power meters designed for certification can also automatically perform the necessary types of measurements, test multiple fibers at once, and perform opposite-direction tests by simply reversing the connections on the meters, or by changing cables in a patch panel. www.itarchitect.com /article/NMG20021203S0009   (1496 words)

Optical Fibre The optical power budget must be greater then the all of the cable plant losses (such as attenuation, losses due to splices and connectors, etc.) for the installation to work properly. Receive sensitivity and transmitter power are used to calculate the optical power budget available for the cable. Sensitivity is the counterpart to power for transmitters. homepage.ntlworld.com /alan.smith25/optical_fibre.htm   (2634 words)

Optical Link Loss Budget According to the table, 12% of the optical power actually reaches the receiver, so 88% of the light output by the transmitter was lost somewhere along the way. The only time that transmitter optical output power and receiver optical sensitivity need to be specified is when the transmitter and receiver are bought separately. The next factor involves the losses due to optical connectors that may be in the optical path. www.fiber-optics.info /articles/loss-budget.htm   (750 words)

Glossary of Eye and Vision Terms Corrected with additional optical power, which may be supplied by a plus lens (spectacle or contact) or by excessive use of the eye's own focusing ability (accommodation). Increase in optical power by the eye in order to maintain a clear image (focus) as objects are moved closer. Type of refractive surgery in which the cornea is reshaped to change its optical power. www.eyeglossary.net   (750 words)

optical fiber An optical fiber (or fibre in British English) is a transparent thin fiber for transmitting light. The optical fiber can be used as a medium for telecommunication and networking because it is flexible and can be bundled as cables. This has greatly reduced the cost of optical networking, particularly over undersea spans where the cost reliability of amplifiers is one of the key factors determining the performance of the whole cable system. www.fact-library.com /optical_fiber.html   (750 words)

Fotec's Textbook - Chapter 7 The optical power margin of the link is determined by two factors, the sensitivity of the receiver, which is determined in the bit error rate curve above and the output power of the transmitter into the fiber. This receiver power depends on two basic factors: how much power is launched into the fiber by the transmitter and how much is lost by attenuation in the optical fiber cable that connects the transmitter and receiver. The power from the transmitter coupled into the optical fiber determines the transmitted power. www.gemini-inc.com /appnotes/optical/fotext/fobook7.htm   (750 words)

Optical Link Loss Budgets The optical power characteristics of the client side interfaces for the single-mode and multimode transponder modules are shown in Table 4-2. Typically, in point-to-point topologies, the OSC optical power budget is the distance limiting factor, while in ring topologies, the data channel optical power budget is the distance limiting factor. Signal power loss or gain is never a fixed amount of power, but a portion of power, such as one-half or one-quarter. www.cisco.com /univercd/cc/td/doc/product/mels/15540/1_11a/design/man_loss.htm   (750 words)

AEFOS - Glossary - O Optical output is the amount of optical power which can be coupled into a given optical fibre. An optical amplifier increases the power of an optical signal without converting any of the signals from optical to electrical energy and then back to optical. The two most common optical amplifiers are those made from doped fibre, such as the EDFA or erbium doped fibre amplifier, which amplify with a laser pump diode and a section of erbium doped fibre, and semiconductor laser amplifiers. www.aefos.com /html/glossary/o.htm   (750 words)

Method of setting power for a reproducing beam to be applied to a magneto-optical disc, and method of reproducing data from a magneto-optical disc - US Patent 6552980 The power determined from the data is supplied to the optical pickup 13, which applies a reproducing laser beam of the intensity represented by that data, to the magneto-optical disc 1. In the method and apparatus according to the invention, power optimal for a reproducing beam to be applied at a position on a magneto-optical disc is obtained by curvilinear approximation based on the powers calculated by calibration performed at least two points on the radius of the disc. The power control section 19 controls the output of the optical pickup 13, i.e., the intensity of a laser beam the optical pickup 13 emits. www.patentstorm.us /patents/6552980.html   (750 words)

Light Source and Power Meter Testing, by Ed Hall When calculating the power budget for a new link it is necessary to allow a margin above the minimum light level required by the receiver to allow for the changes that occur during the life of the link, including equipment aging and optical path changes. The difference between the Light Source output and the received power level at the far end is the loss through the optical path, and is often referred to as the link loss or the insertion loss of the path, or simply as the attenuation. The difference in light level between what the optical transmitter puts out to the minimum level of light required by the optical receiver to work correctly is called the optical power budget. homepages.ihug.co.nz /~edhall/fiber/lspm.htm   (621 words)

Bluebell Opticom Ltd - broadcast fibre optic solutions fibre optics glossary The ratio (expressed in units of dB) of optical power reflected by a component or an assembly to the optical power incident on a component or assembly that is introduced into a link or system. Pertaining to a device that responds to optical power, emits or modifies optical radiation, or utilises radiation for its internal operation. A method of characterising a fibre wherein an optical pulse is transmitted through the fibre and the resulting backscatter and reflections are measured as a function of time. www.bluebellcomms.co.uk /glossaryO.html   (386 words)

Fiber Optic Technology -- former Fiberoptic Products News This combined a higher minimum optical output power and relaxed EOL receiver sensitivity of -21 dBm in order to meet the optical power budget defined by the LR-2 specification. The higher output power is achieved using an LN modulator + CW laser combination, with which it is easier to achieve high output power compared with ILM (due to the fact that there is no carrier saturation in the LN modulator).. The significant reduction in power consumption for short reach applications can be attributed to the change in LD module (LDM) type from cooled to un-cooled, a move from those with thermo-electric coolers (TECs), to those without. www.fpnmag.com /scripts/ShowPR.asp?PUBCODE=025&ACCT=0005131&ISSUE=0304&RELTYPE=pr&PRODCODE=0000&PRODLETT=A   (2039 words)

Optimization of FTTH Passive Optical Networks NexCor Optical Fiber is a full spectrum fiber, 100 percent compatible with other standard single-mode fibers, that enables simplification of PON deployment by increasing the SBS power limitation and reduction of the cost per subscriber through longer reach, larger coverage and utilization of simpler electronic equipment. SBS occurs when a high power optical signal, such as that required for analog video transmission, generates variations in the fiber’s optical properties and scatters optical signals in the reverse direction. The power launched at either the CO/HE or the CPE has to be enough to compensate for all losses introduced by all components, splices and the fiber itself, with enough margin to reach the other receiver at an acceptable level. www.corningcablesystems.com /web/access/asg.nsf/ehtml/passive   (1799 words)

d7600_ae.doc The optical link shall be tested with either a power meter, at a minimum, or OTDR to ensure the link budget (overall path loss) plus an added 3dB of optical safety margin does not exceed the optical power budget as submitted in article 2.05. All optical connectors on cable shall be cleaned in compliance to optical connector manufactures specifications and covered with dust caps until connection to the fiber optic module. All optical fiber cables shall be properly installed and terminated with the mating optical connectors as submitted in article 2.07 (A). www.ifs.com /EtherNav/d7600_ae.doc   (540 words)

ns.optical User-defined optical components, including transmitters, receivers, amplifiers and dispersion compensators, are modelled to calculate the power, dispersion and noise characteristics of every optical path and fibre. Optical Power: Transmitter power, receiver sensitivity, loss-loss and amplifier gain. NetScene Optical will find the best topology for the optical elements from the equipment and parameter data specified by the user, as well as find the optimal routes for the light waves through the network. www.nexxys.com /netcene_optical.htm   (540 words)

Fised attenuators for singlemode and multimode optical fiber The connectorized plug-in optical attenuators are very easy to use and install and it is possible to avoid the problems caused by a power margin, for example in very short links, where the receivers can become overload. In many optical fiber applications it is necessary to reduce the optical power level in the cable. Fised attenuators for singlemode and multimode optical fiber www.telnet-ri.es /ingles/atenua_fijo.html   (540 words)

DWDM in Metropolitan Area Networks Optical power budgets, or link loss budgets, are a critical part of planning an optical network. Because optical power loss (or gain) is measured in a logarithmic value, decibels (dBs), the combined effect of all contributing elements can be calculated using simple addition. The goal in calculating optical loss is to ensure that the total loss does not exceed the span budget. www.cisco.com /univercd/cc/td/doc/product/mels/dwdm/dwdm_app.htm   (540 words)

Novel laser design cuts optical power penalties: News from Zarlink Semiconductor This degradation - called the power penalty - is measured in optical decibels. Zarlink large-aperture VCSEL achieves dramatic reduction in power penalty A key challenge in designing 10Gbit/s VCSELs is to increase the density of information-carrying photons passing through the aperture of the laser. In an optical transmitter-receiver link, factors such as noise, attenuation, dispersion and jitter combine to degrade the quality of the light signal as it travels along the fibre. www.electronicstalk.com /news/mif/mif119.html   (540 words)

NTT Network Innovation Laboratories: Optical soliton transmission system Optical solitons in optical fiber are maintained by the balance of the nonlinear optical index and the group velocity dispersion of the fiber. In addition, we have shown that the use of the DM soliton improves the power margin and the dispersion tolerance of long distance transmission systems. As enabling technologies for these transmission systems, we are studying generation and transmission techniques for ultra short optical pulses ; fiber gratings for the dispersion compensation and equalization ; and the application of ultra fast optical pulses to optical signal processing. www.onlab.ntt.co.jp /en/pt/soliton   (540 words)

EETimes.com - In-P HBTs fill high- speed, low power optical tranceiver requirements A basic receive/transmit system for optical fiber communication shows the critical locations where the highest data rate circuits and components are required. In 1998, we demonstrated a fully integrated 7.5 Gbit/sec optical receiver ASIC that monolithically integrated all the critical components, including a photo diode, the amplifier stage, clock and data recovery circuit (CDR), demultiplexer, and word-synchronization logic. Optical transceiver modules require both digital and analog circuits — sometimes on the same chip. www.eetimes.com /story/OEG20020510S0073   (540 words)

EEE Links Vol. 1, No. 2, Page 2 The test is similar to the component optical power output and receiver sensitivity threshold test, except that all the components on the bus are interrogated and tested using their remote terminal addresses from the test connector. Dedicated busses are used to reduce overall optical power losses and message traffic for a particular network by minimizing the number of remote terminals in the network. The reduction in fiber optic connector losses by use of a PC polished, multi-cable 38999 connector is important because the overall system optical power margin increases as connection losses are reduced. nepp.nasa.gov /eeelinks/vol_01/no_02/eee1-2b.html   (540 words)

LDM80 Series : Signal Powered Fiber Optic Modem The LDM80 optical transmitter may be used with a wide range of fiber sizes. Signal powered fiber optic modem, 25 pin female RS-232 connector, ST fiber optic connector Signal powered fiber optic modem, 25 pin male RS-232 connector, ST fiber optic connector www.omega.com /ppt/pptsc.asp?ref=LDM80   (322 words)

M7i Internet Router Hardware Guide The optical power budget must allow for the sum of component attenuation, power penalties (including those from dispersion), and a safety margin for unexpected losses. A functional optical data link depends on modulated light reaching the receiver with enough power to be correctly demodulated. An efficient optical data link must have enough light to exceed the minimum power that the receiver requires to operate within its specifications. www.juniper.net /techpubs/hardware/m7i/m7i-hwguide/prepare-fiber-attenuation-dispersion.html   (298 words)

RS422 Converter, Fiber Optic Converter - Telebyte - Model 272A The optical power budget for the Model 272A is 12 dB. Power to operate the Model 272A is supplied by a small, wall mounted, 9 Volt AC transformer and line cord. In normal applications the distance between a pair of Model 272A's will be at least 2KM (6,600 ft). www.telebytedatacom.com /catalog/products/272.htm   (205 words)

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