Biomolecules and nanostructures
The Optical Sciences group studies the interaction of light and matter. Our current focus is on detection and sensing/imaging with an emphasis on the development of integrated photonics. We are part of Twente University's Department of Science and Technology and member of the MESA+ institute.
Bessel-beam Grueneisen relaxation photoacoustic microscopy with extended depth of field(full pdf)
Junhui Shi, Lidai Wang, Cedric Noordam, Lihong V. Wang
Journal of Biomedical Optics
vol. 20 issue 11 p116002 Nov 02, 2015
The short focal depth of a Gaussian beam limits the volumetric imaging speed of optical resolution photoacoustic microscopy (OR-PAM). A Bessel beam, which is diffraction free, provides a long focal depth, but its side lobes deteriorate image quality when the Bessel beam is directly employed to excite photoacoustic (PA) signals in OR-PAM. We present a nonlinear approach based on the Grueneisen relaxation effect to suppress the side-lobe artifacts in PA imaging. This method extends the focal depth of OR-PAM and speeds up volumetric imaging. We experimentally demonstrated a 1-mm focal depth with a 7-μm lateral resolution and volumetrically imaged a carbon fiber and red blood cell samples