Long distance distributed fiber optic sensing (DFOS) and WDM communications over repeated fiber spans using all-raman amplification and coding schemes

A long-distance distributed fiber optic sensing (DFOS) and wavelength division multiplexed (WDM) telecommunications system comprising:

• an optical fiber sensor including a plurality of optical fiber cable spans, each individual one of the plurality of optical fiber cable spans including at least one Raman pump;
• a DFOS interrogator system in optical communication with the optical fiber sensor, the DFOS interrogator system including a code sequence generator that generates a coded interrogation sequence, the DFOS interrogator system configured to generate the coded interrogation sequence and introduce the generated coded interrogation sequence into the optical fiber sensor and receive scattered sensing data in response to the introduced generated coded interrogation sequence;
• an analyzer configured to analyze the scattered sensing data received by the DFOS interrogator system;
• a WDM transmitter configured to generate and introduce non-sensory WDM telecommunications signals into the optical fiber sensor;
• a wavelength selective switch (WSS) in optical communications with the DFOS interrogator system, the WDM transmitter, and the optical fiber sensor, the WSS interposed between the DFOS interrogator system and the optical fiber sensor and the WSS interposed between the WDM transmitter and the optical fiber sensor;
• and
• an optical circulator interposed between the WSS and the optical fiber sensor;
• wherein the DFOS coded interrogation sequence and the non-sensory telecommunications signals are simultaneously introduced into the optical fiber sensor;
• wherein one or more of the plurality of optical fiber cable spans exhibit both forward and backward Raman amplification;
• and
• wherein the one or more of the plurality of optical fiber cable spans that exhibit both forward and backward Raman amplification include at least two Raman pumps, one for the forward Raman amplification and another one for the backward Raman amplification.