Tag: Giovanni Volpe

Detection of Hyperosmotic Stress by Raman published in Anal. Chem.

Real-time detection of hyperosmotic stress response in optically trapped single yeast cells using Raman microspectroscopy.

Real-time detection of hyperosmotic stress response in optically trapped single yeast cells using Raman microspectroscopy
Gajendra P. Singh, Caitriona M. Creely, Giovanni Volpe, Helga Grötsch & Dmitri Petrov
Analytical Chemistry 77(8), 2564–2568 (2005)
DOI: 10.1021/ac048359j

Living cells survive environmentally stressful conditions by initiating a stress response. We monitored changes in the Raman spectra of optically trapped Saccharomyces cerevisiae yeast cell under normal, heat-treated, and hyperosmotic stress conditions. It is shown that when glucose was used to exert hyperosmotic stress, two chemical substancesglycerol and ethanolcan be monitored in real time in a single cell.

Generation of Cylindrical Vector Beams published in Opt. Commun.

Generation of cylindrical vector beams with few-mode fibers excited by Laguerre–Gaussian beams.

Generation of cylindrical vector beams with few-mode fibers excited by Laguerre–Gaussian beams
Giovanni Volpe & Dmitri Petrov
Optics Communications 237(1), 89–95 (2004)
DOI: 10.1016/j.optcom.2004.03.080

We propose a novel method to efficiently produce light beams with radial, azimuthal, and hybrid polarization, through a few-mode fiber excited by a Laguerre–Gaussian beam. With different input polarization we can selectively excite different combinations of modes from the LP11 group. We propose to show how to transform the output beam into a cylindrical vector beam in free-space through various polarization transformations.