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.

Date Published: 7 November 2007
PDF: 9 pages
Proc. SPIE 6739, Electro-Optical Remote Sensing, Detection, and Photonic Technologies and Their Applications, 67391F (7 November 2007); doi: 10.1117/12.737362

Published in SPIE Proceedings Vol. 6739:
Electro-Optical Remote Sensing, Detection, and Photonic Technologies and Their Applications
Gary W. Kamerman; Keith A. Krapels; John C. Carrano; Arturas Zukauskas; Ove K. Steinvall; Keith L. Lewis; Keith A. Krapels, Editor(s)