Systems and methods for actively monitoring and managing the integrity of an optical fiber communications link. The optical fiber link integrity is monitored to guard against intrusions and other security breaches. In one embodiment, a local and a remote active monitoring system are coupled by four fiber paths that provide primary and back-up transmit and receive paths between communication equipment. In one embodiment, a security light signal is transmitted using a secondary wavelength that differs from the wavelength used to transmit a user data light signal and travels in an opposite direction relative to the user data light signal. An active monitoring system monitors both administrative information contained within the security light signal and the intensity of the security light signal to manage the integrity of the fiber optic link. Methods are provided to characterize events impacting the fiber optic link integrity.