In recent years the application of nano-porous templates, such as anodic alumina and PTFE, in the production of cylindrical nanostructures has been vast. In our work we used porous alumina membranes to produce luminescent nanowires from polystyrene and silica. The silica wires were fabricated by infiltration of a TEOS derived sol-gel into 200 nm diameter porous alumina membranes with vacuum assistance followed by annealing at 400 °C. Polystyrene luminescent, magnetic nanowires have been fabricated using a similar technique. The wires were studied by optical, confocal and transmission electron microscopy. Silica nanowires demonstrated a broad luminescence spectrum due to interstitial carbon defect emission. Polystyrene nanowires have demonstrated strong emission and interesting magnetic behaviour. Both polystyrene and silica maghemite loaded nanowires show alignment to an external magnetic field. We believe that these silica and polystyrene nanowires might find potential applications in photonics, bio-sensing and biological imaging.
In this paper we describe a novel technique for the fabrication of aluminosilicate microfibres and microtubes which are
shown to act as optical cylindrical microresonators. The alumosilicate microfibres and microtubes were fabricated by
using vacuum-assisted wetting and filtration of silica gel through a microchannel glass matrix. The microfibres and
microtubes were studied using Scanning Electron Microscopy (SEM), micro-photoluminescence spectroscopy and
fluorescence lifetime imaging confocal microscopy. In the emission spectra of the micro-resonators we find very narrow
periodic peaks corresponding to the whispering gallery modes of two orthogonal polarizations with quality factors up to
3200. A strong enhancement in photoluminescence decay rates at high excitation power demonstrates the occurrence of
amplified spontaneous emission from a single microtube. These microtubes show a large evanescent field extending
many microns beyond the tube radius. Potential applications for these novel microresonators will be in the area of optical
microsensors for a single molecule detection of biological and chemical species, including anti-terrorism and defense
sectors.
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.