Patent ID: 6583899
Filing Date: 2003-06-24
Classification: H04B

Abstract:
A method of shutting-down an optical communication system having spans of optical transmission fiber interspersed serially between optical transformation sites and a plurality of amplifier sites containing first direction bound and second direction bound optical amplifiers, the optical transformation sites being selected from a group comprising a transmitter, an add/drop multiplexer, an opto-electronic regenerator, and a receiver, comprising the steps of:detecting a drop in signal power of a first direction bound optical signal below a threshold at an input to a first direction bound optical amplifier in a first amplifier site and decreasing pump power for the first direction bound optical amplifier below a predetermined safety level; decreasing pump power for a corresponding second direction bound optical amplifier in the first amplifier site below the predetermined safety level; detecting a drop in signal power of a second direction bound optical signal below the threshold at an input to a downstream second direction bound optical amplifier in a second amplifier site immediately downstream from the first amplifier site and decreasing pump power for the downstream second direction bound optical amplifier below the predetermined safety level; decreasing pump power for a corresponding first direction bound optical amplifier in the second next amplifier site below the predetermined safety level; decreasing pump power below the predetermined safety level for only all other second direction bound and first direction bound optical amplifiers positioned between the first amplifier site and a next upstream optical transformation site and between the second amplifier site and a next downstream optical transformation site; and waiting a predetermined length of time after the last decreasing step; forcing the first direction bound amplifier, the second direction bound amplifier, and the all other second direction bound and first direction bound optical amplifiers to disregard a shutdown command from a control circuit within the optical communication system.