Optical Characterization of Dynamic CMUTs Using Zygo Optical Profilometers: An Alternative to Laser Doppler Vibrometers

Laser Doppler Vibrometers (LDVs) are the most common optical characterization equipment for CMUTs since LDVs characterize both static and dynamic CMUTs in terms of static deflection and resonance frequency, respectively. However, LDVs are not always available for the researchers of ultrasonic transducers. Zygo optical profilometer is also used as an optical characterization equipment for CMUTs but only for static CMUTs. In this study, we show that Zygo optical profilometers could be used to characterize dynamic CMUTs as well. The study shows that Zygo optical profilometers could be an alternative to LDVs performing both static and dynamic analyses of CMUTs. A circular CMUT cell fabricated by wafer bonding technique is characterized using Zygo optical profilometer. The first three resonance frequencies obtained by Zygo optical profilometer match the resonance frequencies obtained by impedance analyzer and ANSYS modal analysis. The equipment could also be used to characterize other ultrasonic transducers such as PMUTs and piezoelectric transducers.2024-0171