title: Near-infrared optical-resolution photoacoustic microscopy.
abstract: Compared with visible light (380-700 nm), near-infrared light (700-1400 nm) undergoes weaker optical attenuation in biological tissue; thus, it can penetrate deeper. Herein, we demonstrate near-infrared optical-resolution photoacoustic microscopy (NIR-OR-PAM) with 1046 nm illumination. A penetration depth of 3.2 mm was achieved in chicken breast tissue ex vivo using optical fluence within the American National Standards Institute (ANSI) limit (100  mJ/cm2). Beyond ∼0.6  mm deep in chicken breast tissue, NIR-OR-PAM has shown finer resolution than the visible counterpart with 570 nm illumination. The deep imaging capability of NIR-OR-PAM was validated in both a mouse ear and a mouse brain. NIR-OR-PAM of possible lipid contrast was explored as well.
authors.affiliation: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA.
authors.forename: Pengfei
authors.initials: P
authors.lastname: Hai
authors.affiliation: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA.
authors.forename: Junjie
authors.initials: J
authors.lastname: Yao
authors.affiliation: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA.
authors.forename: Konstantin I
authors.initials: KI
authors.lastname: Maslov
authors.affiliation: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: Optical Imaging Laboratory, Department of Biomedical Engineering, Washington University in St. Louis, One Brookings Drive, St. Louis, Missouri 63130, USA.
authors.forename: Lihong V
authors.initials: LV
authors.lastname: Wang
mesh_terms: D000818:Animals; D001921:Brain / Q000033:anatomy & histology / Q000098:blood supply; D002645:Chickens; D003952:Diagnostic Imaging / Q000295:instrumentation; D004423:Ear / Q000033:anatomy & histology / Q000098:blood supply; D006801:Humans; D007259:Infrared Rays; D053844:Lasers, Solid-State; D051379:Mice; D008853:Microscopy / Q000295:instrumentation*; D055620:Optical Phenomena; D061088:Photoacoustic Techniques / Q000295:instrumentation*