ISE Magazine, August 2018
AU G U S T 2 0 1 8 WWW ISEMAG COM 1 2 1 FIBER EXPERT legacy G 652 with its high attenuation in the E band with the new G 652D fiber Losses will be determined as a ratio in length of the amount of fiber of each type in the span Unless you have an OTDR with a 1383 nm laser you will not be able to accurately measure the fibers attenuation See Figure 1 Fiber optic system manufacturers identify the distance requirements at various data rates to address how to select and integrate optical components to achieve the desired signal quality over the length of the span Service providers should always calculate a loss budget to identify the attenuation requirements for the span and its individual components and work with their transmission equipment vendor for the optimum solution Be sure to consider these options when greater attenuation is required Increase the lasers optical power Increase the receivers photo detectors sensitivity Select the optimum fiber type and wavelength Minimize physical plants losses caused by connections splices splitters and optical switches Incorporate optical amplifiers Summary Today as transmission rates increase the use of new transmission bands will require new OSP testing to assure attenuation measurements are accurate In FTTH FTTB CWDM and long haul applications new wavelengths have been specified but can have high attenuation if not tested to the expected operating wavelengths Remember that as data rates increase so do the effects of optical dispersion That topic will be addressed in next months article While youre attending ISE EXPO 2018 be sure to meet with your test equipment manufacturers to discuss these new challenges and to look at migration options for your future testing requirements n Figure 1 ITU Specified Bands Courtesy OFS Optics
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