Apparatus and method for characterizing pulsed optical signals

A method for characterizing a detected signal in a communication system, the method comprising the steps of:

• a) deriving two analogous signals from the detected signal;
• b) subjecting one of the two analogous signals to a controllably variable time delay;
• c) recombining the two analogous signals to obtain an interference signal;
• and
• d) processing the interference signal to determine at least one of a predefined set of parameters related to the detected signal, wherein the processing step comprises mapping the interference signal as a function of the variable time delay, deriving oscillatory component of said function, and obtaining amplitude profile of the oscillatory component versus the variable time delay.

A method for characterizing a pulsed optical signal, comprising the steps of:

• a) splitting the optical signal into two beams;
• b) applying a controllably variable time delay to one of the two beams;
• c) recombining the two beams to obtain a diamond diagram resulting from the coherent interference effect;
• d) using a maximum opening of the optical diamond diagram to determine performance clearance between a zero-bit and a one-bit of the optical signal.