Abstract: The present invention provides a bidirectional wavelength division multiplexed optical communication system having bidirectional optical service channels. The bidirectional WDM optical communication system includes a bidirectional optical waveguide configured to carry a bidirectional optical communication signal comprising counterpropagating WDM optical signals. Each WDM optical signal includes plural optical channels and an optical service channel. A bidirectional optical add-drop multiplexer optically communicates with the waveguide. A first optical service channel selector optically communicates with the first bidirectional optical add-drop multiplexer input/output port.

Abstract: The present invention provides a bidirectional wavelength division multiplexed optical communication network useful in numerous network configurations. The network includes a bidirectional optical waveguide carrying counter-propagating wavelength division multiplexed optical signals each including plural channels. Several optical nodes are positioned along the bidirectional optical waveguide, each of which includes an optically-amplified bidirectional optical add-drop multiplexer. Each bidirectional optical add-drop multiplexer includes channel selectors for selecting at least one optical channel from each of the counter-propagating WDM optical signals. Each optical node further includes at least one optical transmitter for supplying an optical channel to be added by the bidirectional optical add-drop multiplexer to the bidirectional optical waveguide and at least one optical receiver for receiving an optical channel dropped from the bidirectional optical waveguide by the bidirectional add-drop multiplexer.

Abstract: The present invention provides bidirectional add-drop multiplexers for bidirectional wavelength division multiplexed optical communication systems. In a first configuration, the bidirectional add-drop multiplexer includes six three-port optical circulators. The bidirectional add-drop multiplexer is placed at any point along a bidirectional transmission waveguide configured to carry two counter-propagating wavelength division multiplexed optical signals. The bidirectional waveguide places the west-east wavelength division multiplexed optical signal into the first port of the first circulator where it is routed to the first port of the second optical circulator. A channel selector is positioned between the second and third optical circulators for add/dropping optical channels. The through channels and any added channels exit through the first port of the fourth circulator as a counter-propagating east-west WDM optical signal enters the first port.