Dispersion tolerant optical system and method

Abstract

An optical communication system and method of use are described. The system comprises an optical source adapted to receive a digitally encoded data signal comprising sequences of data at a data rate (B) and comprising two signal levels representing a first state and a second state of the data signal, the optical source being adapted to produce an optical signal substantially frequency modulated with frequency excursion Δν comprising a first instantaneous frequency (ν 0 ) associated to the first state and a second instantaneous frequency (ν 1 ) associated to the second state; an optical converter adapted to receive the substantially frequency modulated optical signal, the optical converter having an optical transfer function varying with frequency and including at least one pass band, the at least one pass band having a peak transmittance and at least a low-transmittance region.

We claim: 
     
         1 . An optical communication system for transmitting digital optical signals comprising:
 an optical source adapted to receive a digitally encoded data signal comprising sequences of data and comprising two signal levels representing a first state and a second state of the data signal, the optical source being adapted to produce an optical signal substantially frequency modulated with frequency excursion Δν comprising a first instantaneous frequency (ν 0 ) associated to the first state and a second instantaneous frequency (ν 1 ) associated to the second state;   an optical converter adapted to receive the substantially frequency modulated optical signal, the optical converter having an optical transfer function varying with frequency and including a high-transmittance region and a low-transmittance region,   the first instantaneous frequency (ν 0 ) of the frequency modulated optical signal being spectrally aligned within the low-transmittance region of the optical transfer function of the optical converter; and   the second instantaneous frequency ν 1  of the frequency modulated optical signal is spectrally aligned with a positive slope portion of the high-transmittance region of the optical transfer function of the optical converter,   thereby converting the substantially frequency modulated signal into a substantially amplitude modulated signal.