Abstract

Dense-wavelength-division multiplexed multichannel systems have the potential to provide enormous aggregate capacity. Such networks may require Fabry-Perot (FP) filters to demultiplex the channels and optical amplifiers, such as erbium-doped fiber amplifiers, to compensate for splitting or transmission losses.¹ Although these amplifiers provide gain, they also introduce amplified spontaneous emission (ASE) noise which beats with itself and all the channels passing through the filter.² In this paper, relevant noise sources are identified when utilizing a FP filter demultiplexer. Using Lorentzian approximations, simple expressions which contain easily measurable parameters are derived for both the signal-to-noise ratio (SNR) and power penalty. The optical filter must be amply wide to transmit the selected signal but sufficiently narrow to limit the ASE-related noise. The power penalty from rejected channels is weakly related to the ASE and decreases rapidly as the spacing increases.

© 1992 Optical Society of America