How to calculate the probability of detecting a coherent state after passing through the optical path?

Question

Computer networks

Total A = 1350, which is completely wrong ...
That is, every 0.0135 parcel will be registered. And then how?

As I understand it, you need to further calculate the losses and take them into account as in a conventional optical communication channel =\ .... Where L = 50 meters, and the second indicator is the loss in the fiber, I guess.
8) Silent horror, or I share something wrong.

Answer 1

0.5