Photo-induced ultrasound microscopy for photo-acoustic imaging of non-absorbing specimens

: Tcarenkova E, Koho SV, Hanninen PE

: Costa MFM

: International Conference on Applications of Optics and Photonics

Publisher: SPIE-INT SOC OPTICAL ENGINEERING, PO BOX 10, BELLINGHAM, WA 98227-0010 USA

: 2017

: Third International Conference on Applications of Optics and Photonics

: THIRD INTERNATIONAL CONFERENCE ON APPLICATIONS OF OPTICS AND PHOTONICS

: PROC SPIE

: UNSP 104532O

: Proceedings of SPIE

: 10453

: 6

: 978-1-5106-1384-3

: 0277-786X

DOI: https://doi.org/10.1117/12.2276315

Photo-Acoustic Microscopy (PAM) has raised high interest in in-vivo imaging due to its ability to preserve the near-diffraction limited spatial resolution of optical microscopes, whilst extending the penetration depth to the mm-range. Another advantage of PAM is that it is a label-free technique - any substance that absorbs PAM excitation laser light can be viewed. However, not all sample structures desired to be observed absorb sufficiently to provide contrast for imaging. This work describes a novel imaging method that makes it possible to visualize optically transparent samples that lack intrinsic photo-acoustic contrast, without the addition of contrast agents. A thin, strongly light absorbing layer next to sample is used to generate a strong ultrasonic signal. This signal, when recorded from opposite side, contains ultrasonic transmission information of the sample and thus the method can be used to obtain an ultrasound transmission image on any PAM.