Consider a plane wave with free space wave length of 1550nm

Consider a plane wave, with free- space wave length of 1550nm, propagating in a lossy medium. What is the highest extinction coefficient that can be tolerated, in order to keep the propagation loss below 1 dB/cm?

Solution

= 4k/_0; k=extinction coefficient

10Log₁₀ = 1 dB

=10^0.1 = 1.26

₀ = 1550 nm = 1550 x 10^-7 cm

k= _0./4 = 1550 x 10^-7 x 1.26 / 4 x 3.14 = 1.55 x 10^-5