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Showing posts with label Interview questions for optical technicians. Show all posts
Showing posts with label Interview questions for optical technicians. Show all posts

Sunday, 9 November 2014

Test Equipment used in Optical fiber maintenance

Testing Parameters in Optical Network

Following are the testing parameters used in optical network.

Trans optical power
•Receive optical power
•OSNR
•Dispersion (Read about dispersion here)
•Wavelength
•Wavelength deviation
•Fiber loss (Read about Fiber loss here)
•Connector loss
•Splicing loss

Optical Power Meter (OPM)


•OPM measure the average optical power out of an optical fiber.
•Power meters are calibrated at the typical wavelengths used in fiber optics, 850, 1300 and 1550 nm.
•Some meter uses Auto wavelengths Recognition feature.



Optical Light Source(OLS)


•OLS along with Optical Power Meter is used to make measurements of optical loss or attenuation in fibers and connectors.
•It should be compatible with the type of fiber in use (singlemode or multimode with the proper core diameter) and the wavelength.
•Sources may be either LED's or LASERS.
•Sometimes optical power meters are combined with an Optical Light Source (OLS) or Visual Fault Locator (VFL).




OTDR


•Optical Time Domain Reflectometer (OTDR) is used for estimating the fiber’s length and overall attenuation, including splice and mated-connector losses and to locate faults, such as breaks.
•OTDR functions by injecting a series of optical pulses into the fiber under test, using LASER.
•It requires access to only one end of the fiber.

Fiber Trace at OTDR





Optical Spectrum Analyzer (OSA)


•Optical signal monitoring on live channels.
•Able to analyze
–Optical Power
–Optical wavelength
–OSNR of each wavelength
–Spectral width of optical source



Visual Fault Locator


•Visual Fault Locator is used to inject the visible light to visually trace fiber.
•It covers the range where OTDRs are not useful.
•This is used for buffered fiber and even jacketed single fiber cable if the jacket is not opaque to the visible light.