Open AccessConstellation diagram analysis of DPSK signal regeneration in a saturated parametric amplifier
Author(s) -
Maria Sköld,
Yang Jiang,
H. Sunnerud,
Magnus Karlsson,
Shunri Oda,
Peter A. Andrekson
Publication year - 2008
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.16.005974
Subject(s) - optics , demodulation , signal (programming language) , phase modulation , physics , signal regeneration , modulation (music) , amplifier , phase noise , constellation diagram , optical amplifier , amplitude and phase shift keying , phase (matter) , amplitude , amplitude modulation , optical fiber , pulse amplitude modulation , frequency modulation , telecommunications , optoelectronics , acoustics , computer science , detector , laser , bit error rate , channel (broadcasting) , bandwidth (computing) , pulse (music) , quantum mechanics , programming language , cmos
The regeneration of 10 Gbit/s differential phase shift keying (DPSK) signals in a saturated fiber optic parametric amplifier (FOPA) acting as an optical intensity regenerator is investigated. The regeneration properties are investigated in amplitude and phase separately by means of coherent detection and constellation diagram analysis. A significant reduction of the amplitude fluctuations is observed and the measured signal-to-noise ratio (SNR) after DPSK demodulation is increased up to 10 dB. However, from the constellation analysis it is found that the FOPA introduces phase noise to the signal. The FOPA induced phase noise originates from pump amplitude fluctuations that are transferred to the signal through cross-phase modulation.