Modulation effect induced by continuous waves in semiconductor optical amplifiers

Nonlinearities in SOAs have been deeply investigated both theoretically and experimentally. Moreover, many Simulative models have been proposed, so far. The most used simulative approach is based on Rate Equations, relating the carrier density to the overall optical power traveling the amplifier. Aim of this paper is to propose an enhanced general model for nonlinearities induced in SOAs employed in WDM systems, overcoming the limitations of Rate Equations based model. Our model relates the carrier density to the optical field, and it allows to evaluate the interchannel crosstalk due to nonlinear interaction between channels, as a function of the signal waveform. Besides the theoretical approach, preliminary experimental results confirm the accuracy of this model in describing the demonstrates the crosstalk due to nonlinear interaction

Enhanced optical gain clamping for upstream packet based traffic on hybrid WDM/TDM-PON using fiber Bragg grating

In this paper, we propose a method to mitigate the temporal power transients arising from Erbium doped fiber amplifiers (EDFAs) on packeted/bursty scenario. The technique, applicable on hybrid WDM/TDM-PON for extended reach, is based on a low power clamping provided by a distributed feedback (DFB) laser and a fiber Bragg grating (FBG). An improvement in the data signal Q factor was achieved keeping the clamping control signal with a low power, accompanied by a maximum reduction in the gain excursion of 1.12 dB. (C) 2010 Elsevier B.V. All rights reserved.FEDERFEFOFTOMAR-PONFCTSFRH/BD/28904/200