Super-resolution photoacoustic imaging through a scattering wall

Area of Science:

• Optics
• Acoustics
• Biomedical Imaging

Background:

• Imaging through scattering media is challenging due to light distortion.
• Wavefront shaping offers potential for compensating scattering effects.
• Focusing light without direct access behind scattering walls is crucial for practical applications.

Purpose of the Study:

• To develop a method for focusing light through scattering media using photoacoustic feedback.
• To achieve sub-acoustic optical focusing for enhanced imaging resolution.
• To demonstrate improved signal-to-noise ratio and resolution in imaging behind scattering materials.

Main Methods:

• Utilizing photoacoustic feedback for wavefront optimization.
• Combining spatially non-uniform ultrasound transducer sensitivity with evolutionary optical mode competition.
• Employing an evolutionary algorithm to optimize the optical field for a high-intensity focus.

Main Results:

• Demonstrated the formation of a single, high-intensity optical focus significantly smaller than the acoustic focus.
• Achieved sub-acoustic optical focusing, not limited by absorber size.
• Showcased imaging behind scattering media with up to 10x improvement in signal-to-noise ratio and 5-6x sub-acoustic resolution.

Conclusions:

• Photoacoustic feedback is an effective method for wavefront optimization in scattering media.
• The developed technique enables high-resolution, high-contrast imaging through scattering barriers.
• This approach holds promise for various applications requiring non-invasive imaging through turbid environments.