Detection scheme of coherence-multiplexed sensor signals using an optical loop with a frequency shifter: sensitivity enhancement

A sensitivity enhancing scheme in a coherence-multiplexed sensor system using an optical loop with a frequency shifter is described. In order to enhance sensitivities of the multiplexed sensors, an erbium-doped fiber amplifier is introduced into the optical loop, which compensates for loop loss. The sensitivities can be experimentally enhanced by optical amplification in the fiber amplifier and, consequently, we can successfully multiplex four sensors.<>