Theory of backscattering effects in waveguides.

Associated with a signal transmitted down a waveguide are multiple back and forth scatterings. These produce a delayed decaying interference trailing a sharp signal pulse. An analytical description of this phenomenon enables an estimate of its effect on an optical waveguide's information-carrying capacity. For the example of a signal-to-interference ratio of 100 in a 1-km fiber of 20-dB attenuation, a bit rate limitation occurs when the fractional backscattered power captured per unit length exceeds 1.3 dB/km.