AVS 52nd International Symposium
    Nanometer-Scale Science and Technology Wednesday Sessions
       Session NS-WeM

Paper NS-WeM11
Towards the Fabrication of Ultra High Throughput Optical Fiber Probes

Wednesday, November 2, 2005, 11:40 am, Room 210

Session: Nanometer Scale Imaging
Presenter: B.C. Gibson, University of Melbourne, Australia
Authors: B.C. Gibson, University of Melbourne, Australia
S.T. Huntington, University of Melbourne, Australia
J. Canning, University of Sydney, Australia
K. Lyytikainen, University of Sydney, Australia
J.D. Love, Australian National University, Australia
Correspondent: Click to Email
Scanning near field optical microscopy (SNOM) has become an important characterization tool across all major disciplines of science. The ability to "cheat" the resolution limit in optical microscopy has enabled characterization of structures on a nanometer scale. At the heart of the technique is a metal coated scanning probe, which features a sub-wavelength aperture as a source or collector of light that explores the near-field of the sample surface. The key problem with this type of SNOM probe is the excessive loss that occurs, which effectively limits the sensitivity of the microscope. The high loss arises from attenuation through the sub-wavelength aperture, which is unavoidable. In addition, the high loss stems from an interaction with the metal coating at the tapered region of the tip. Preliminary theoretical models of tapered air-silica structured fibers suggest that this interaction with the metal may be reduced with the use of these fibers, along with a new type of fiber called a Fractal Fiber (special class of air-silica fiber), instead of using standard single-mode optical fibers. Tapering of these fibers has been performed using a custom-built CO@sub 2@ laser-based fiber pulling system to produce a prototype ultra high throughput optical probe. Initial optical throughput measurements have shown improved power levels to that of conventional SNOM probes. This suggests that the fiber design and fabrication is critical to the successful advancement of SNOM probes.