Patent ID: 7783197
Filing Date: 2010-08-24
Classification: H04J

Abstract:
1. A method of transmitting a WDM optical signal, comprising: modulating a plurality of optical channels that are each located at a different wavelength from one another with a respective one of a plurality of information-bearing electrical signals, wherein channel spacings between adjacent ones of the plurality of optical channels are selected such that the optical channels give rise to selected FWM terms that lie outside a channel bandwidth of the optical channels; multiplexing each of the modulated optical channels to form a WDM optical signal; and forwarding the WDM optical signal onto an optical transmission path, wherein the channel spacings between each channel i and its adjacent channel is equal to a constant frequency offset plus a frequency offset δf where B/2 is a minimum acceptable frequency separation and α i is a scaling factor that satisfies the inequality conditions |α m +α (i+j−m) −α i −α j |>1 where 1≦i+j−m≦n_m≠i≠j, n is the number of optical channels, and i and j are indices denoting any of the optical channels between channel 1 and channel n, which, along with a given one of the optical channels m, produce the selected FWM terms.