SIMULATION OF ASE NOISE ACCUMULATION IN A WAVELENGTH ADD-DROP MULTIPLEXER CASCADE

This letter presents a computer simulation of a cascade of wavelength add-drop multiplexers (WADM's) each consisting of optical amplifiers, a multiplexer/demultiplexer pair, gain equalizing attenuators and 2 x 2 optical switches. It is shown that one of the eight wavelengths can propagate through more than 50 equidistant WADM's in a wavelength-divi sion multiplexed (WDM) optical network before its optical signal-to-no ise ratio (SNR) drops below acceptable levels, These simulations indic ate that a national scale transparent WDM network is feasible.