An ultraviolet-transparent ultrasound transducer for label-free high-resolution photoacoustic histological imaging

초록

Ultraviolet photoacoustic microscopy (UV-PAM) enables label-free photoacoustic (PA) histopathology by leveraging the strong optical absorption of DNA and RNA in cell nuclei. However, the resolution of conventional UV-PAM remains limited compared to hematoxylin and eosin (H&E)-stained histology images. This limitation primarily arises from systemic opto-ultrasound alignment issues in existing UV-PAM systems employing opto-ultrasound beam combiners (OUCs) or ring-shaped ultrasound transducers. In this study, we present the first ultraviolet-transparent ultrasound transducer (UV-TUT) to overcome these challenges. The UV-TUT achieves a numerical aperture of 0.38, resulting in a lateral resolution of 0.47 μm. Furthermore, we developed a UV-TUT-based PAM system and demonstrated significantly improved resolution on mouse brain tissue sections compared with conventional OUC-based UV-PAM. This work is expected to enhance the clinical utility of label-free PA histopathology by addressing the resolution limitations of current UV-PAM systems. © 2025 IEEE.

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