Attenuation is the loss of optical power as light travels down a fiber. It is measured in decibels (dB/km). Over a set distance, a fiber with a lower attenuation will allow more power to reach its receiver than a fiber with higher attenuation.
While low-loss optical systems are always desirable, it is possible to lose a large portion of the, initial signal power without significant problems. A loss of 50% of initial power is equal to a 3.0 dB loss. Any time fibers are joined together there will be some loss. Losses for fusion splicing and for mechanical splicing are typically 0.2 dB or less.
Attenuation can be caused by several factors, but is generally placed in one of two categories: intrinsic or extrinsic.
June 11, 2011