Fiber Loop Mirrors Composed of Two Dispersion Shifted Fibers and a Single Mode Fiber

Four wave mixing (FWM) process in a fiber loop mirror constructed from two dispersion shifted fibers (DSF) along with a single mode fiber (SMF) in between them is theoretically investigated. It is shown that this loop inherently separates the idler wave from the input pump and signal waves. Meanwhile the presence of SMF results in a higher signal to idler conversion efficiency for signals close to the pump.