K. Inoue et M. Jinno, SIGNAL IMPROVEMENT EFFECT IN O E-E/O CONVERSION USING AN ELECTROABSORPTION (EA) MODULATOR/, IEEE photonics technology letters, 9(1), 1997, pp. 109-111
O/E-E/O conversion using an electro-absorption (EA) modulator is descr
ibed from the viewpoint of noise transfer characteristics, where input
optical signals are converted to electrical signals and the EA modula
tor is driven by the inversely amplified electrical signals. A thresho
ld property in the EA modulation characteristic suppresses signal fluc
tuation in the input ''on''-state, provided that the ''on''-level volt
age supplied to the modulator exceeds a threshold. Experiments in whic
h amplifier ASE light was intentionally imposed on the signal light sh
owed improvement in allowable ASE level, and confirmed the noise suppr
ession effect.