Bias-sensitive transparent single-element ultrasound transducers using hot-pressed PMN-PT

Abstract

Here we introduce electrostrictive hot-pressed lead magnesium niobate (PMN) with low lead titanate (PT) doping as a candidate transparent transducer material. We fabricate transparent high-frequency single-element transducers and characterize their optical, electrical, and acoustic properties. PMN-PT may offer sensitivity advantages over other transducer materials such as lithium niobate owing to its high electromechanical efficiency and bias-voltage sensitivity. The transparency of the fabricated transducer was measured ∼67% at 532 nm wavelength with a maximum electromechanical coefficient of ∼0.68 with a DC bias level of 100 V. The photoacoustic impulse response showed a center frequency of ∼27.6 MHz with a −6 dB bandwidth of ∼61% at a DC bias level of 40 V. Results demonstrate that the new transparent transducers hold promise for future optical-ultrasonic and photoacoustic imaging applications.