Question

In a 10 km long fiber, the output power is 25% of the input power. What is the loss coefficient?

Answer 1

Length of the cable is 10km;

Suppose input power is x;

So output power is 25% of x;

Output power = (25*x)/100 = 0.25x;

Loss coefficient = alpha;

Po = Pi.e^(-alpha*L);

Po/Pi = e^(-alpha*10);

log(0.25) = (-alpha*10)

loss coefficient = alpha = 0.06 dB per km