title: Objective-free optical-resolution photoacoustic microscopy.
abstract: 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, a significantly improved 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 objective-free OR-PAM using a fiber optic Bessel beam generator. In this approach, no objective lens is required and, beneficially, the complexities of conventional OR-PAM systems can be greatly relieved. We have obtained photoacoustic images of a carbon fiber with a diameter of ∼6  μm, whose lateral resolution was measured to be better than 6 to 7 μm.
authors.affiliation: State University of New York, The University at Buffalo, Bio Optics and Acoustics Laboratory, Department of Biomedical Engineering, Buffalo, New York 14260, USA. chulhong@buffalo.edu
authors.forename: Chulhong
authors.initials: C
authors.lastname: Kim
authors.forename: Sungjo
authors.initials: S
authors.lastname: Park
authors.forename: Jongki
authors.initials: J
authors.lastname: Kim
authors.forename: Sungrae
authors.initials: S
authors.lastname: Lee
authors.forename: Changho
authors.initials: C
authors.lastname: Lee
authors.forename: Mansik
authors.initials: M
authors.lastname: Jeon
authors.forename: Jeehyun
authors.initials: J
authors.lastname: Kim
authors.forename: Kyunghwan
authors.initials: K
authors.lastname: Oh
mesh_terms: D002244:Carbon / Q000737:chemistry; D005336:Fiber Optic Technology / Q000295:instrumentation*; D007091:Image Processing, Computer-Assisted; D033401:Microscopy, Acoustic / Q000295:instrumentation / Q000379:methods*; D061088:Photoacoustic Techniques / Q000295:instrumentation / Q000379:methods*; D014867:Water / Q000737:chemistry
chemical_list: D014867:Water; D002244:Carbon