A Polymer Asymmetric Mach–Zehnder Interferometer Sensor Model Based on Electrode Thermal Writing Waveguide Technology

This paper presents a novel electrode thermal writing waveguide based on a heating-induced refractive index change mechanism. The mode condition and the electrode thermal writing parameters were optimized, and the output patterns of the optical field were obtained in a series of simulations. Moreover, the effect of various adjustments on the sensing range of the nanoimprint M–Z temperature sensor was analyzed theoretically. A refractive index asymmetry Mach–Zehnder (M–Z) waveguide sensor with a tunable refractive index for a waveguide core layer was simulated with a length difference of 946.1 µm. The optimal width and height of the invert ridge waveguide were 2 μm and 2.8 μm, respectively, while the slab thickness was 1.2 μm. The sensing accuracy was calculated to range from 2.0896 × 10(4) to 5.1252 × 10(4) in the 1.51–1.54 region. The sensing fade issue can be resolved by changing the waveguide core refractive index to 0.001 via an electrode thermal writing method. Thermal writing a single M–Z waveguide arm changes its refractive index by 0.03. The sensor’s accuracy can be improved 1.5 times by the proposed method. The sensor described in this paper shows great prospects in organism temperature detection, molecular analysis, and biotechnology applications.