Reflection-mode photoacoustic microscopy with dark-field laser pulse illumination and high-numerical-aperture ultrasonic detection is designed and implemented in noninvasively imaged blood vessels in the skin in vivo. Dark-field optical illumination minimizes the interference caused by strong photoacoustic signals from superficial structures. A high-numerical-aperture acoustic lens provides high lateral resolution, 45-120 µm in this system. A broadband ultrasonic detection system provides high axial resolution, estimated to be ∼15 µm. The optical illumination and ultrasonic detection are in a coaxial confocal configuration for optimal image quality. The system is capable of imaging optical-absorption contrast as deep as 3 mm in biological tissue.
© 2005 Optical Society of America
Konstantin Maslov, Gheorghe Stoica, and Lihong V. Wang, "In vivo dark-field reflection-mode photoacoustic microscopy," Opt. Lett. 30, 625-627 (2005)