Characterization of ultrasonic transducers using a fiberoptic sensor

Area of Science:

• Acoustics
• Biomedical Engineering
• Materials Science

Background:

• Polyvinylidene fluoride (PVDF) hydrophones are standard for ultrasonic transducer characterization but have limitations.
• PVDF hydrophones cause field disturbance and spatial averaging due to their finite aperture.
• PVDF hydrophones are delicate and prone to damage, limiting their practical application.

Purpose of the Study:

• To evaluate a previously proposed fiberoptic ultrasonic sensor for measuring ultrasonic fields.
• To compare the performance of the fiberoptic sensor against a calibrated PVDF needle hydrophone.
• To assess the sensor's capability in characterizing a range of ultrasonic transducers.

Main Methods:

• Utilized a fiberoptic ultrasonic sensor to measure characteristics of six focused and unfocused transducers.
• Covered a frequency range from 2.25 MHz to 20 MHz.
• Compared fiberoptic sensor results with those from a 0.5 mm effective diameter PVDF needle hydrophone.

Main Results:

• The fiberoptic sensor demonstrated excellent agreement with the PVDF needle hydrophone.
• Temporal responses of transducers measured by the fiberoptic sensor matched PVDF hydrophone results.
• Beam profiles of transducers measured by the fiberoptic sensor showed excellent agreement with PVDF hydrophone data.

Conclusions:

• The fiberoptic ultrasonic sensor is a viable alternative to PVDF hydrophones.
• The sensor accurately measures ultrasonic transducer temporal responses and beam profiles.
• Fiberoptic sensing offers a promising approach for overcoming limitations of conventional hydrophones in ultrasonic field measurements.