Method of applying time offset chromatic dispersion, dispersive optical apparatus, and an optical fiber transmission system using the apparatus

Dispersive optical apparatus including:

• a color-splitting system for receiving a light beam, the light beam constituting a composite beam to be processed and being constituted by light including a plurality of spectrum components modulated by a plurality of unit signals respectively corresponding to the components, the components being superposed in the beam, the system being capable of responding by yielding an incoming split beam propagating in a longitudinal direction of the beam, the split beam being constituted by a plurality of incoming pencils formed by the components and respectively corresponding to the components, the pencils being juxtaposed transversely in the beam, the light of each of the pencils being modulated by said corresponding unit signal;
• a stair-shaped mirror having steps constituted by a plurality of reflective areas that are offset from one another in the longitudinal direction, and that respectively correspond to the incoming pencils, one of the areas constituting a reference area, each reflective area being disposed so as to receive and to reflect the corresponding incoming pencil while constraining the light of the pencil to travel along a path having an optical path length and a propagation time that correspond to the area so as to yield an outgoing pencil corresponding to the incoming pencil and to the area, the light of the outgoing pencil being modulated by a unit signal having a delay equal to the propagation time relative to the unit signal which modulated the light of the incoming pencil, a time offset corresponding to the area, to the incoming pencil, and to the outgoing pencil being constituted by the difference between that propagation time and the propagation time corresponding to the reference area, the set of outgoing pencils constituting an outgoing split beam in which the pencils are juxtaposed transversely;
• and
• a color-recombining system for receiving the outgoing split beam and for yielding a processed composite beam in which said components are superposed once more.