Optical-resolution photoacoustic microscopy (OR-PAM) becomes a premier microscopic imaging tool in biomedicine because it provides agent-free optical absorption information in tissues. By tightly focusing light to a spot, the fine lateral resolution can be achieved in OR-PAM. The focal spot size is typically determined by the numerical aperture of the used objective lens. Here, we demonstrate focus-free OR-PAM using a Bessel beam generator. In this approach, no objective lens is required. We have photoacoustically imaged a carbon fiber with a diameter of ~6 μm, and the measured lateral resolution was ~6-7 μm. Beneficially, the complexities of the existing OR-PAM systems can be greatly relieved.

Date Published: 4 March 2013
PDF: 6 pages
Proc. SPIE 8581, Photons Plus Ultrasound: Imaging and Sensing 2013, 85812F (4 March 2013); doi: 10.1117/12.2003303

Published in SPIE Proceedings Vol. 8581:
Photons Plus Ultrasound: Imaging and Sensing 2013
Alexander A. Oraevsky; Lihong V. Wang, Editor(s)