In this report we evaluate a novel approach to nanoscopic optical imaging. It employs the active manipulation of optically transparent nanoparticles, which serve as coherent nano-emitters of light. By critical evaluation of all the components involved in this novel microscopic arrangement, we find that nanoparticles made out of high-refractive index materials, such as TiO2, CdS and ZnO, are the most suitable for the efficient trapping, manipulation, and generating sufficient amount of the third-harmonic light, which can be used for fluorescent imaging.
KEYWORDS: Nanoparticles, Particles, Optical imaging, Near field optics, Signal detection, Spatial resolution, Microscopy, Near field scanning optical microscopy, Diffraction, Light sources
Our ability to understand the structures and functions of living systems on a cellular and molecular level is mostly determined by the availability of imaging techniques capable of accessing a nanoscopic spatial resolution as well as providing structural information on molecular systems in vivo. While optical methods provide non-invasiveness, their spatial resolution is limited by a fundamental diffraction limit revealed more than 150 years ago by Ernst Abbe. This report addresses this grand-challenge and suggests a novel way of minimally invasive nanoscopic optical imaging inside a living cell. A powerful combination of optical tweezers, nonlinear optics and material science holds a promise of achieving unprecedented resolution of live-cell imaging, which should significantly advance our knowledge of molecular functions on a cellular level.
KEYWORDS: Particles, Multiplexing, Nanoparticles, Near field optics, Near field, Near field scanning optical microscopy, Signal detection, Optical tweezers, Metals, Microscopes
We propose a novel microscopic arrangement that allows highly multiplexed nanoscopic imaging. We use a laser-trapped microparticles to concentrate light in a nanoscopic volume in a close vicinity of a particle. By arranging these microparticles in a close-packed two-dimensional array, parallel multiplexing can be achieved both for light excitation and signal collection.
We report laser-induced phase transformations in CdS nanocrystals under radiation of high-power nanosecond laser pulses with wavelength of 532 nm and 355 nm. The observed changes in size distribution of nanocrystals as well as the changes of their crystal structure from orthorhombic to cubic are uncovered by absorption spectroscopy, high-resolution transmission electron microscopy and selected area electron diffraction.
A fluorescent study of aquatic humic substances (AHS) in ice has been performed in order to make the first step toward elaboration of a remote technique for their diagnostics in aqueous solid-phase-containing systems. The fluorescence spectra of AHS in ice samples were obtained for different temperatures ranged from 0 to 150 degree(s)C. An unusual distortion of the fluorescence band shape has been observed at low temperatures. Some conclusions on the form of presence of AHS in ice were made on the base of the spectroscopic study. Several specific experiments were carried out to characterize the crystallization process in AHS aqueous solutions.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.