WAVELENGTH DIVISION MULTIPLEXED PASSIVE OPTICAL NETWORK FOR MONITORING DISTRIBUTION OPTICAL FIBERS AND UPWARD LIGHT SOURCES, ESPECIALLY CONCERNED WITH DISCRIMINATING THE TROUBLE AND DETERIORATION OF THE UPWARD LIGHT SOURCE OF EACH SUBSCRIBER EQUIPMENT FROM THE DISCONNECTION AND DETERIORATION OF A DISTRIBUTION OPTICAL FIBER FOR CONNECTING EACH SUBSCRIBER EQUIPMENT WITH A LOCAL OFFICE

摘要

PURPOSE: A WDM(Wavelength Division Multiplexed) PON(Passive Optical Network) for monitoring distribution optical fibers and upward light sources is provided to discriminately monitor the state of a distribution optical fiber connecting a subscriber equipment with an RN(Remote Node) and the state of an upward light source located at a subscriber equipment by using a wideband luminous source and a reflecting element. CONSTITUTION: In a WDM PON for monitoring distribution optical fibers and upward light sources, a CO(Central Office)(100) comprises a wideband light source, a 1x2 distributor(14), wavelength division multiplexers(13), and reflected light receivers(12). Each subscriber equipment(30) comprises a wavelength division multiplexer and an optical signal reflecting element(70). For a high-power wideband light source, two-layered erbium-doped fiber amplifiers(51,51'), driven by a pump laser diode(53), and a band pass filter(52) are used. The band pass filter(52), located between the first and second erbium-doped fiber amplifiers(51,51'), limits the wavelength band of a wideband light source so as to be discriminated from the wavelength bands of upward/downward light sources. Moreover, as a limited wideband light source signal is amplified through the second erbium-doped fiber amplifier(51'), a high-power wideband signal can be created more efficiently.