Optical Supervisory Channel for High Span Loss Optical Communication Systems

An optical supervisory channel includes a transmit path that propagates optical supervisory signals to a high span loss optical fiber span having an optical loss that is greater than 35 dB. A wavelength division multiplexer adds the optical supervisory signals to the high span loss optical fiber span. A second wavelength division multiplexer extracts the optical supervisory signals from the high span loss optical fiber span. A receive path propagates the optical supervisory signals away from the high span loss optical fiber span. The optical supervisory channel also includes a means for reducing a bit error rate of the optical supervisory channel.