System and method for rapidly achieving optimum dispersion in optical transmission systems

A method for monitoring dispersion, said method comprising:

• providing an optical sample of at least one selected wavelength channel;
• providing a radio frequency (RF) carrier at a frequency that differs from the baud of the at least one selected wavelength channel by about 100 kHz;
• coupling the optical sample through an erbium doped fiber amplifier (EDFA);
• coupling the optical sample through a receive photodetector;
• amplifying the output signal of the photodetector;
• adjusting the amplified output signal;
• coupling the adjusted amplified output signal to one input of a microwave mixer;
• coupling the RF carrier signal to the other input of the microwave mixer;
• mixing the output signal of the mixer with the RF carrier frequency to obtain an alternating current (a.c.) signal component;
• terminating the output of the mixer and a.c. coupling the output to a low frequency (LF) amplifier;
• coupling the a.c. signal component through an active bandpass filter;
• coupling the a.c. signal component to an average detector;
• coupling the resulting direct current (d.c.) signal through an A/D converter;
• and
• communicating the d.c. signal to a data-processing unit.