Patent ID: 8009983

Claim:
A repeater for an optical communication system configured to transmit test signals and to monitor corresponding reflected test signals from both inbound and outbound directions, the repeater comprising: a first amplifier having an input and an output, and for amplifying optical signals; a second amplifier having an input and an output, and for amplifying optical signals; a first high loss loop back (HLLB) path for coupling the output of the first amplifier to the input of the second amplifier, wherein the first HLLB path is configured to pass at least one test signal in a wavelength range and configured to reject wavelengths outside of the wavelength range; a second HLLB path for coupling the output of the second amplifier to the input of the first amplifier, wherein the second HLLB path is configured to pass at least one test signal in a wavelength range and configured to reject wavelengths outside of the wavelength range; and a third HLLB path for coupling the output of the first amplifier to the output of the second amplifier, wherein the third HLLB path is configured to pass a plurality of wavelengths from the output of the first amplifier to the output of the second amplifier, wherein the wavelengths passed by the third HLLB path include wavelengths in the wavelength range and at least one reflected test signal outside of the wavelength range.