Frequency measurement of piezoelectric resonator using laser light

We have previously proposed a piezoelectric sensor configuration using an optical-access method. However, optical measurement of die resonance frequency is rather difficult In this paper, we discuss an optical measurement method that uses the refraction index deviation caused by piezoelectric vibration. In the corresponding detection configuration, a resonator sample is inserted in the optical path of a Mach-Zender interferometer, The resonance frequency can be accurately measured using a long optical fiber. This detection configuration is applicable to the measurement of a resonator array, Resonance frequencies of die array were optically measured simultaneously and with high accuracy.