Dispersin tolerant optical system and method thereof

摘要

According to an aspect, the present invention relates to an optical communication system for transmitting digital optical signals comprising a data generator adapted to generate a digitally encoded data signal comprising sequences of data at a data rate and comprising two signal levels representing a first state and a second state of the data signal; an optical source adapted to receive the data signal and to produce an optical signal substantially frequency modulated with frequency excursion ”½ comprising a first instantaneous frequency (von) associated to the first state and a second instantaneous frequency (½ 1 ) associated to the second state; an optical converter that receives the substantially frequency modulated (FM) optical signal and has an optical transfer function varying with frequency and including at least one pass band with at least a peak transmittance and at least a low-transmittance region, wherein the first frequency of the FM optical signal is spectrally aligned with the low-transmittance region of the optical transfer function of the optical converter so as to convert the substantially FM signal into a substantially amplitude modulated (AM) signal and the at least one pass band has a FWHM comprised between 70% and 200% of the data rate of the FM optical signal According to a second aspect, the present invention relates to an optical communication system including an electrical signal path between a data generator and an optical source emitting a substantially FM optical signal with frequency excursion ”½, the electrical signal path being adapted to receive the data signal generated by the data generator and to input the data signal into the optical source and having a low-pass transfer function with a cut-off frequency f c not larger than about 2.2(”½).