Title :
Improvement of Intensity-Modulated Signal With Feed-Forward Control
Author :
Kunigita, Naoya ; Kawahara, Hiroki ; Inoue, Kyo
Author_Institution :
KDDI, Tokyo, Japan
Abstract :
In fiber transmission systems, optical signals can be degraded by noise light such as amplified spontaneous emission from optical amplifiers and coherent crosstalk light leaking from other channels due to imperfections in switches and/or filters in photonic network nodes. In this paper, we propose a feed-forward control circuit that mitigates such signal degradation in intensity-modulated signals. Our scheme is an optical/electrical hybrid circuit consisting of an optical coupler, photo-detector, and Mach-Zehnder intensity modulator (MZ-mod). The transmissivity of the MZ-mod is used to suppress fluctuations in the ??on?? signal state. In addition, the proposed circuit also improves the extinction ratio by adjusting the operating conditions.
Keywords :
amplitude shift keying; feedforward amplifiers; fluctuations; intensity modulation; optical control; optical crosstalk; optical fibre amplifiers; optical fibre couplers; optical fibre networks; optical modulation; optical noise; photodetectors; superradiance; MZ-mod; Mach-Zehnder intensity modulator; amplified spontaneous emission; coherent crosstalk light leaking; extinction ratio; feed-forward control circuit; fiber transmission systems; filters; fluctuation suppression; intensity-modulated signal; noise light; on signal state; operating conditions; optical amplifiers; optical coupler; optical signals; optical/electrical hybrid circuit; photodetector; photonic network nodes; signal degradation; switches; transmissivity; Erbium; Fluctuations; Noise; Optical amplifiers; Optical attenuators; Optical crosstalk; Optical filters; Amplified spontaneous emission (ASE); feed-forward control; in-band crosstalk; on-off keying (OOK);
Journal_Title :
Lightwave Technology, Journal of
DOI :
10.1109/JLT.2012.2206559
