Raman amplifier system and method with integrated optical time domain reflectometer

An optical subsystem, configured in a Raman amplifier, optical subsystem comprising:

• a transmitter optically connected to a switch;
• a receiver;
• circuitry coupled to the transmitter and the receiver;
• and
• a circulator with a first port optically connected to the switch, a second port optically connected to a fiber, and a third port optically connected to the receiver,
• wherein the circuitry is configured to selectively operate as an Optical Time Domain Reflectometer (OTDR) and a telemetry channel based on configuration of the switch, transmitter, and the circuitry.

A Raman amplifier method, with an integrated Optical Time Domain Reflectometer (OTDR) in a Raman amplifier, the Raman amplifier method comprising:

• providing one or more Raman pumps, wherein the one or more Raman pumps are configured as a Raman amplifier;
• providing a subsystem comprising a transmitter, a receiver, and circuitry, wherein the subsystem is configured to selectively operate as an OTDR and a telemetry channel based on configuration of a switch optically coupled to the transmitter and configuration of the circuitry, and wherein the transmitter has a wavelength that does not interfere with the one or more Raman pumps, but which experiences gain due to the one or more Raman pumps;
• and
• using the circuitry with the telemetry channel to measure gain due to Raman amplification in a fiber based on measurements one or more Raman pumps on and off to provide an estimate of Raman gain and to provide a data channel to an adjacent Raman amplifier module.