Patent ID: 7079772

Claim:
An optical signal generator, comprising: an optical source adapted to generate an optical signal including a plurality of carrier signals at respective generated carrier frequencies that are adjustable by corresponding frequency control signals, each carrier signal being associated with a respective target carrier frequency; a multi-channel optical filter having a filter input port connected to the optical source and having a plurality of filter output ports, each filter output port being associated with a respective optical channel having a pass band surrounding a different respective channel center frequency; for each target carrier frequency, a first detection unit and a second detection unit respectively associated with said target carrier frequency, each connected to a different one of the filter output ports, and each adapted to output an indication of a characteristic of said target carrier frequency in the optical signal present at the filter output port to which it is connected, wherein the filter output port connected to one of the first detection unit and the second detection unit respectively associated with a first target carrier frequency is connected to one of the first detection unit and the second detection unit respectively associated with a second target carrier frequency different from the first target carrier frequency; and a control unit connected to the first detection unit and the second detection unit respectively associated with each target carrier frequency and to the optical source, said control unit being operable to generate the frequency control signal corresponding to each particular carrier signal as a function of the output of the first detection unit and the second detection unit respectively associated with the target carrier frequency that is associated with said particular carrier signal, thereby to align the generated carrier frequency of said particular carrier signal with the target carrier frequency associated with said particular carrier signal.