Abstract: A method of optical communication includes providing a plurality of optical signals each associated with a distinct channel of a composite optical signal. A unique pilot tone signature is superimposed on each channel. The spectral composition of each signature includes a plurality of frequencies. In one embodiment, binary frequency shift keying at a frequency fm is used to shift between instantaneous frequencies f1 and f2 wherein f2+?f=f1??f=fc. Choosing ? ? ? f f m ? 1.1602 produces a spectrum having a plurality of dominant components at least some of which have substantially the same amplitude. A method of detecting the presence of a selected pilot tone signature having a plurality n of dominant spectral components F1 . . . Fn includes generating a power spectrum P0(f). Sk(f) is calculated as a product of a plurality of frequency shifted versions of P0(f), where k?{1 . . . n}. The existence of a dominant spectral component at Fk indicates the presence of the selected pilot tone signature.

Abstract: A method of optical communication includes providing a plurality of optical signals each associated with a distinct channel of a composite optical signal. A unique pilot tone signature is superimposed on each channel. The spectral composition of each signature includes a plurality of frequencies. In one embodiment, binary frequency shift keying at a frequency fm is used to shift between instantaneous frequencies f1 and f2 wherein f2+?f=f1??f=fc. Choosing ? ? ? f f m ? 1.1602 produces a spectrum having a plurality of dominant components at least some of which have substantially the same amplitude. A method of detecting the presence of a selected pilot tone signature having a plurality n of dominant spectral components F1 . . . Fn includes generating a power spectrum P0(f). Sk(f) is calculated as a product of a plurality of frequency shifted versions of P0(f), where k?{1 . . . n}. The existence of a dominant spectral component at Fk indicates the presence of the selected pilot tone signature.

Abstract: A method of optical communication includes providing a plurality of optical signals each associated with a distinct channel of a composite optical signal. A unique pilot tone signature is superimposed on each channel. The spectral composition of each signature includes a plurality of frequencies. In one embodiment, binary frequency shift keying at a frequency fm is used to shift between instantaneous frequencies f1 and f2 wherein f2+?f=f1??f=fc. Choosing ? ? ? f f m ? 1.1602 produces a spectrum having a plurality of dominant components at least some of which have substantially the same amplitude. A method of detecting the presence of a selected pilot tone signature having a plurality n of dominant spectral components F1 . . . Fn includes generating a power spectrum P0(f). Sk(f) is calculated as a product of a plurality of frequency shifted versions of P0(f), where k?{1 . . . n}. The existence of a dominant spectral component at Fk indicates the presence of the selected pilot tone signature.

Abstract: A method of optical communication includes providing a plurality of optical signals each associated with a distinct channel of a composite optical signal. A unique pilot tone signature is superimposed on each channel. The spectral composition of each signature includes a plurality of frequencies. In one embodiment, binary frequency shift keying at a frequency fm is used to shift between instantaneous frequencies f1 and f2 wherein f2+&Dgr;f=f1−&Dgr;f=fc. Choosing 1 Δ ⁢   ⁢ f f m ≈ 1.