Series-coupled fiber double-ring in Mach-Zehnder interferometer for temperature sensing

摘要

We theoretically investigate the properties of the series-coupled fiber double-ring resonator in a Mach-Zehnder interferometer as highly sensitive temperature sensor. By comparison of phase difference between two arms, we acquired suitable phase difference of 0.5π between two arms in a Mach-Zehnder interferometer for sharpest asymmetric line shape around the resonance wavelength. We also analyze the effect of parameters on the sensitivity and the detection limit by measuring the intensity change at a fixed wavelength. For the 30dB signal-to-noise ratio system, the sensitivity and the detection limit can achieve 720.8/°C and 4.16×10~(-6) °C, respectively. These results indicate that this structure is suitable for highly sensitive, compact and stable sensors.