High-sensitivity strain sensor with micron-scale imitation dumbbell structure based on differential temperature self-compensation

A micron-sized dumbbell-like -MZI structure has been developed using hydroxide flame melt taper and arc fusion discharge, with the dumbbell rod region prepared by melt taper drawing and the dumbbell sheet region prepared by arc fusion discharge. This structure has a sensitive light intensity response in the sensing field due to a double-order mode-field coupled excitation region. The geometrical parameters of the dumbbell-like system are optimized theoretically, and the feasibility of the microstructure to achieve high strain sensing sensitivity is analyzed. Experimental results show that the microstructure has a high strain sensing sensitivity of ∼ 0.074 dB/µε and a consistent temperature sensing sensitivity over the entire monitoring wavelength range. Therefore, a light intensity-dependent temperature self-compensation calculation is proposed to achieve a uniform light intensity-strain response for each characteristic peak in the monitored wavelength domain. Since the device has a significant advantage in light intensity modulation and is not affected by polarization light perturbations, it can be used as an alternative light intensity modulation device in optical communication networks and laser research. It can also be used as a probe for medical diagnostic testing based on its enhanced evanescent field properties.