An optical communication system and method for starting up and shutting down
the
system to ensure safety during repair of a fiber break are disclosed. A technique
for shutting down an optical communication system having spans of optical transmission
fiber interspersed serially between optical transformation sites and a plurality
of amplifier sites includes shutting down both amplifiers on either side of a fiber
disruption and both amplifiers in the same amplifier sites serving transmission
in an opposite direction, followed by deactivation of all amplifiers within the
same optical line between optical transformation sites. During startup, amplifiers
enter an operating mode to ignore a system shutdown signal, an amplifier at a terminal
site is forced on, and then successive amplifiers step through an intermediate
safe power level before reaching full operating power.