An alternative optical switch using Mach Zehnder interferometer and two ring resonators

In this paper, we present an experimental investigation of all-optical switch using a symmetric Mach-Zehnder interferometer (MZI) combined with double fiber ring resonators. Here, we replace the ordinary-fiber ring resonator on one arm of MZI by a 980 nm-laser pumped erbium-doped fiber (EDF) ring resonator to form an EDFA. When adjusting the EDF pump power up we note increasing in switching power. Experimental results indicate that using MZI with double EDF ring, switching power is lowered significantly to nanowatt level in comparison with that of MZI with a single EDF ring of milliwatt level.