Patent ID: 7256877
Filing Date: 2007-08-14
Classification: H04B,H04J

Abstract:
1. 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.