A WDM bidirectional self-healing optical ring network is provided in which
an outer ring network and an inner ring network can both handle N optical
signals. The network includes a node; an optical add/drop multiplexer
having a 1.times.N demultiplexer and a 1.times.N multiplexer; a pair of
optical switching devices each connected to an optical fiber link
intervening between the optical add/drop multiplexer and another node on
the both ends of the optical add/drop multiplexer; and, a pair of
circulators each connected between the optical add/drop multiplexer and a
particular optical switching device in the optical switching device pair,
each circulator having three ports, two of the three ports being
connected to a corresponding optical switching device and remaining one
port being connected to the optical add/drop multiplexer.