Transmission penalties due to EDFA gain transients in add-drop multiplexed WDM networks

Abstract

We analyze fiber transmission penalties due to erbium-doped fiber amplifier (EDFA) gain transients in a chain of 10-20 EDFA's with as many as 32 wavelength-division-multiplexed channels. Penalties are a result of increased fiber nonlinearity during channel deletion and amplified-spontaneous-emission noise during channel addition. We find that: (1) the system performance is severely degraded both in single-mode fiber and dispersion shifted fiber due to fiber nonlinearities; (2) the signal-to-noise ratio (SNR) can be reduced by up to 8 dB in a 32-channel system; and (3) a control channel to suppress EDFA-gain and SNR transients may impose an additional penalty which increases with the bit rate.