Large area laser scanning optical resolution photoacoustic microscopy using a fibre optic sensor

Area of Science:

• Biomedical Optics
• Photoacoustic Imaging
• Microscopy

Background:

• Photoacoustic microscopy offers high resolution for biological tissue imaging.
• Traditional systems often require mechanical scanning, limiting imaging speed and area.
• Developing advanced sensors is crucial for improving photoacoustic microscopy capabilities.

Purpose of the Study:

• To introduce a novel laser scanning optical resolution photoacoustic microscopy (LS OR-PAM) system.
• To present a stationary fiber optic sensor for enhanced photoacoustic imaging.
• To demonstrate the system's capability for in vivo microvasculature imaging and functional analysis.

Main Methods:

• A stationary fiber optic sensor with an optically resonant interferometric polymer cavity was developed.
• The system utilizes laser scanning for image acquisition.
• In vivo imaging was performed on a mouse ear model.

Main Results:

• The sensor achieved a low noise equivalent pressure (68.7 Pa) and a broad bandwidth (up to 80 MHz).
• A near omnidirectional response allowed imaging of large areas (>1cm²) without mechanical scanning.
• The system demonstrated a lateral resolution of 8 µm and axial resolution of 21 µm.
• In vivo 3D structural and functional images of mouse ear microvasculature, including blood oxygen saturation, were obtained.

Conclusions:

• The developed stationary fiber optic sensor significantly enhances LS OR-PAM systems.
• The system enables fast, large-area, high-resolution in vivo imaging of microvasculature.
• This technology holds potential for advanced functional and structural studies of biological tissues.