Working principle of variable optical attenuator
Optical attenuators can take a number of different forms and are typically classified as fixed or variable attenuators.
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Wavelength of Optical Attenuator
Wavelength: single mode 1310um, 1550um or dual wavelength; multimode 850um or dual wavelength, equipped with dust cap. An optical attenuator, or fiber optic attenuator, is a device used to reduce the power level of an optical signal, either in free space or in an optical fiber. The basic types of optical attenuators are fixed, step-wise variable, and continuously variable.
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How to calculate a 10dB optical attenuator
A dB = 10 · log 10 (P in /P out) If you know attenuation in dB, switch to "Output values from known dB attenuation". Of course, you also need to be able to determine the attenuator value in decibels required for your application. In this example let's assume that the maximum optical input power a fiber-optic receiver can operate with is -6dBm. The tool computes resistor values in different configurations: R1 = Zo [10dB/20 + 1] / [10dB/20 – 1] R2 = Zo/2 [10dB/10 – 1] / [10dB/20] where R1 is the shunt resistor (to ground). Determine output power in dBm and milliwatts, power reduction ratio, transmittance percentage, and total system loss including insertion loss.
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Why add an optical attenuator
Optical attenuators are commonly used in, either to test power level margins by temporarily adding a calibrated amount of signal loss, or installed permanently to properly match transmitter and receiver levels. They are usually installed at the transmit end of active modules, such as OTU and OSC boards, to prevent the downstream receiver modules from being burnt due to excessively high output optical power. Transmitter power (TP) = 3dBm Receiver maximum optical input power (MP) = -6dBm Total losses (TL) = 5dB Minimum attenuation required = MP + TL – TP = -6dBm + 5dB – 3dBm = – 4 dB At a minimum, a 4 dB attenuator is required.
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What is the cable tray structure for optical fiber
Cable tray is a raceway system designed to protect and route fiber optic patch cords, multi-fiber cable assemblies and intrafacility fiber cable to and from fiber splice enclosures, fiber distribution frames and fiber optic terminal devicesCable tray is a raceway system designed to protect and route fiber optic patch cords, multi-fiber cable assemblies and intrafacility fiber cable to and from fiber splice enclosures, fiber distribution frames and fiber optic terminal devicesSplice trays are internal fiber management structures used to organize, protect, and separate optical fiber splices inside closures, terminal boxes, and distribution enclosures. While there are several specific types of listings for power cables, specifically for tray applications, there is no equivalent tray rating for optical fiber cables. According to the 2014 National Electric Code® (NEC), any listed optical fiber cable is acceptable for a tray application. A fiber optic splice tray is a component of fiber optics management that is designed to securely and efficiently store and organize fiber fusion splice and slack fibers, installed inside fiber splicing closures, enclosures, and cabinets. OCC FOTC cables will withstand aggressive pulling, impact from falling debris, and harsh temperatures.
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