Patent ID: 6441933
Filing Date: 2002-08-27
Classification: H04B,H04J

Abstract:
A signal monitoring apparatus for wavelength division multiplexed (WDM) optical telecommunication networks, comprising:absolute wavelength reference generating means for generating an optical output of a laser stabilized on an absolute wavelength reference, wavelength reference generating means for generating a wavelength reference set having a constant frequency spacing from a wide band optical signal defining a wavelength range, tunable filtering means for receiving the optical output of the laser or one wavelength reference among the wavelength reference set of the constant frequency spacing, or a WDM channel signal which is used in optical telecommunication networks, and control means for counting a gap between the optical output of the laser and the WDM channel signal with a certain frequency value, measuring the optical power of the WDM channel and controlling the wavelength and the optical power of the WDM channel, in which the optical output of the laser passes the tunable filter means.