Abstract: An optical communication system (10), a method (100) for parallel modulation of an optical spectrum and a method (200) for parallel demodulation of the optical spectrum of modulated optical frequencies by the system (10) are described. The optical frequencies are provided in parallel to a modulation section (14) for modulating with data bits from a data signal source (16). The data bits are associated with an optical modulator (58) that controls passage of the optical spectrum at a plurality of predetermined optical frequencies based upon the data bits. The optical frequencies of the optical spectrum, modulated by the data bits, are then transmitted via a communication section (18) to an optical receiver (20) that is coupled to a demodulation section (22) of the system (10). Modulated optical frequencies are received as a modulated optical spectrum and demodulated in parallel by an optical demodulator (92) to derive the data bits.