Optical Pump Induced Thermal Sensitivity Reduction in a Minimized Er/Yb-Codoped-Fiber Mach–Zehnder Interferometer

The intensity and wavelength dependent thermal characteristics of a minimized Er/Yb-codoped-fiber Mach–Zehnder interferometer are demonstrated theoretically and experimentally. It can be used as a high sensitivity temperature sensor if no pump is introduced. However, once a pump is launched into the interferometer, its thermal sensitivity is reduced. Under pump power of 59.4 mW, 3.1 pm/°C and 10.3 pm/°C reductions of its thermal sensitivities are achieved for the resonance dips at short and longer wavelength ranges, respectively. This suggests that its thermal sensitivity can be tuned by introducing into a pump, and its thermal stability can be improved with the pump.