Schlieren visualization of ultrasonic wave fields with high spatial resolution

Area of Science:

• Acousto-optics
• Optical physics
• Ultrasound imaging

Background:

• Acousto-optic interaction is a proven method for visualizing ultrasonic wave fields in transparent liquids.
• High-resolution visualization of pulsed ultrasonic waveforms requires specific pulsed light sources and sensitive optical imaging sensors.

Purpose of the Study:

• To present the technical requirements for high-resolution visualization of ultrasound wave fields.
• To introduce a new, inexpensive Schlieren optical system for pulsed wave field visualization.
• To demonstrate the system's capability for quantitative visualization of ultrasonic wavelengths and amplitude variations.

Main Methods:

• Development and testing of a novel Schlieren optical system.
• Utilizing pulsed light sources and sensitive optical imaging sensors.
• Conducting experiments at 2 MHz and 10 MHz with single transducers and linear arrays.

Main Results:

• The designed Schlieren system is capable of high-resolution, gray-scaled visualization of ultrasound wave fields, including amplitude zero crossings.
• Quantitative visualization of ultrasonic wavelengths and their changes in media with varying sound velocities is achieved.
• The system effectively displays beamforming characteristics of commercial medical ultrasound scanners.

Conclusions:

• The developed Schlieren optical system offers an inexpensive yet effective solution for high-resolution visualization of MHz-range pulsed ultrasound.
• The system enables detailed experimental investigation of wave propagation, including reflection, refraction, and diffraction.
• This technology advances transducer testing, design, and the study of ultrasound-tissue interactions.