Optical power launched into fiber at transmitter end is 150 µW. The

power at the end of 10 km length of the link working in first window is - 38.2 dBm.

Another system of same length working in second window is 47.5 µW. Same length

system working in third window has 50 % of launched power. Calculate fiber

attenuation for each case and mention wavelength of operation.