The simulation and experimental results of the temperature tuning of an -doped fiber (EDF) Mach–Zehnder interferometer (MZI) proposed for sensing applications were presented. The MZI was mechanically induced using two polypropylene long-period fiber gratings made with a pulsed laser. The proposed interferometer device showed four peaks of transmittance and multifiltering around the 1550-nm region, suitable for Telecomm systems. The numerical simulation is simple and is based on rate equations which allows for amplified spontaneous emission behavior prediction and mode propagation. The demonstrated fringe pattern makes the proposed device suitable for multiwavelength sensors based on EDFs.