US 7,623,794 B2 · Wavelength division-multiplex system

Abstract

A power-down delay unit for delaying cutoff of a voltage is provided in a power supply line which supplies electrical power to an optical module of a transponder unit for each optical wavelength. The power-down delay unit assigns different delays for each wavelength. The length of the delay is a time required by an AMP unit to change from an ALC mode to an AGC mode or longer. When the power sources for supplying electrical power to the transponder units becomes faulty and outputs of several wavelengths are simultaneously going to stop, the power-down delay unit delays cutoff of the supply voltage to the optical modules by keeping supply voltage for a while to the optical modules on behalf of power sources enabling the optical modules to operate after the power sources shutdown, so that the actual optical signals gradually stop one by one.

Claims12

Dependent claims

A WDM system which multiplexes a plurality of optical signals having different wavelengths and which are respectively produced by a plurality of modules when the plurality of modules receive a supply of power from a power source, and then transmits a multiplex signal obtained by said multiplexing, the WDM system comprising:

a delay unit including capacitors that store electrical charge while the supply of power from the power source is being received by the plurality of modules,
wherein, when the supply of power from the power source is stopped, the delay unit discharges the capacitors so that the supply of power received by the plurality of modules is stopped at a plurality of different timings, respectively.

Dependencies are inferred from the claim text.

Wavelength division-multiplex system

Life of this patent

Wavelength division-multiplex system

Life of this patent

Abstract

Claims12