Milione G.,Institute for Ultrafast Spectroscopy and Lasers |
Milione G.,City University of New York |
Milione G.,New York State Center for Complex Light |
Dudley A.,South African Council for Scientific and Industrial Research |
And 10 more authors.
Journal of Optics (United Kingdom) | Year: 2015
We experimentally measured the self-healing of the spatially inhomogeneous states of polarization of vector Bessel beams. Radially and azimuthally polarized vector Bessel beams were experimentally generated via a digital version of Durnin's method, using a spatial light modulator in concert with a liquid crystal q-plate. As a proof of principle, their intensities and spatially inhomogeneous states of polarization were experimentally measured using Stokes polarimetry as they propagated through two disparate obstructions. It was found, similar to their intensities, that their spatially inhomogeneous states of polarization self-healed. The self-healing can be understood via geometric optics, i.e., the interference of the unobstructed conical rays in the shadow region of the obstruction, and may have applications in, for example, optical trapping. © 2015 IOP Publishing Ltd.
News Article | November 11, 2015
The neuroscience community is saluting the creation of a "Golden Window" for deep brain imaging by researchers at The City College of New York led by biomedical engineer Lingyan Shi. This is a first for brain imaging, said Shi, a research associate in City College's Institute for Ultrafast Spectroscopy and Lasers, and the biology department. The breakthrough holds promise for the noninvasive study of the brain and breasts in greater detail than possible today. Working with Distinguished Professor of Physics Robert R. Alfano and Adrian Rodriguez-Contreras, an assistant professor of biology, Shi's team proved theoretically and experimentally that deep imaging of the brain is possible using light at wavelength 1600-1880nm (nanometer). This is dubbed the "Golden Window" for imaging. In the past, near-infrared (NIR) radiation has been employed using one and two-photon fluorescence imaging at wavelengths 650-950 nm for deep brain imaging. This is known as optical window 1. Shi, who earned a Ph.D. in biomedical engineering from CCNY's Grove School of Engineering in 2014, said the current research introduces three new optical windows in the NIR region. And she demonstrates the windows' potential for deeper brain tissue imaging due to the reduction of scattering that causes blurring. Published by the Journal of Biophotonics, her study sheds light on the development of next generation of microscopy imaging technique, in which the "Golden Window" may be utilized for high resolution deeper brain imaging. The next step in the research is in vivo imaging in mice using Golden Window wavelength light.