Optical Fiber Communications 4th Edition by Gerd Keiser

تمرين 8

A continuous 40-km-long optical fiber link has a loss of 0.4 dB/km.
( a ) What is the minimum optical power level that must be launched into the fiber to maintain an optical power level of 2.0 W at the receiving end
( b ) What is the required input power if the fiber has a loss of 0.6 dB/km