Strain sensing based on a microbottle resonator with cleaned-up spectrum.

In this Letter, a microbottle-resonator-based strain sensor with individual mode distribution and recognizable resonance spectrum was proposed and demonstrated. A cleaned-up spectrum was achieved by inscribing horizontal microgroove scars close to the bottle center. The inscribing parameters of these grooves were designed according to the field distribution of the modes, and the obtained spectrum showed excellent consistency with theoretical analysis. The shift in the resonance peak with increasing stretching force was investigated, and the corresponding strain sensitivities were 0.085 pm/μϵ for transverse electric polarization and 0.136 pm/μϵ for transverse magnetic polarization, which could be further increased by using materials with smaller elastic moduli.