Patent ID: 8472626

Claim:
A system for the optical transmission of a binary code comprising a transmitter and a receiver and a reception line extending between said transmitter and said receiver, said transmitter comprising: generation means (SPU) arranged to generate an electromagnetic signal having physical quantities; transmission modification means (AT 1 , DP, MP 1 ) arranged to modify at least one physical quantity characterising the electromagnetic signal according to the binary code so as to generate a modified transmission signal; a transmission line (CQ) being arranged to transmit the modified transmission signal to the receiver; the receiver comprising: reception modification means (AT 2 , MP 2 , OL 2 ) arranged to modify the modified transmission signal so as to generate a modified reception signal; detection means (F 2 , D 1 , D 2 ) arranged to detect the values of the physical quantities characterising the modified reception signal, wherein the transmission modification means are arranged to modify at least a first physical quantity and a second physical quantity of the electromagnetic signal, in which the first physical quantity is an intensity of spectral components of the electromagnetic signal and the second physical quantity is a relative phase of the spectral components, so as to generate the modified transmission signal, the modified transmission signal being chosen randomly from at least a first type of modified transmission signal and a second type of modified transmission signal, in which, for the first type of modified transmission signal, the first physical quantity is constant, and the second physical quantity depends on a bit value of the binary code such that the first type of modified transmission signal comprises encoding states that differ only by the second physical quantity, and for the second type of modified transmission signal the second physical quantity is constant and the first physical quantity depends on a bit value of the binary code such that the second type of modified transmission signal comprises encoding states that differ only by the first physical quantity, and in that the detection means are arranged to determine a value of the first physical quantity and a value of the second physical quantity.