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Speaker: Professor John Love, Department of Quantum Science, College of Physical Sciences, Australian National University
Date: 8 July 2009
Time: 2pm
Venue: Mountbatten Seminar Room
Abstract:
In the optical frequency domain, metals can be regarded as dielectric materials, albeit with an imaginary part to the refractive index that represents the opacity and is normally much larger than the real part. The guidance provided by a metal-clad, dielectric-core fibre is more easily understood in terms of the respective dielectric constants rather than the refractive index.
Because of the large variation between metal and silica dielectric constants, Maxwell’s equations are employed to determine modal propagation characteristics and their solution is generally numerically intensive. An exact, explicit analytical solution is available for a surface plasmons propagating along a planar dielectric-metal interface.
Simple perturbation solutions are possible when only a small fraction of modal power propagates within the metal. Examples will be presented for the cases of (i) a tapered, metal-clad, single-mode fibre for scanning near-field optical microscopy application, and (ii) multimode propagation inside a hollow, multimode metal-coated capillary for laser light delivery.
Biography:
Professor John Love has researched various theoretical aspects of guided wave phenomena in fibres, waveguides and a range of light processing devices at ANU over the last 36 years. He is also Convenor for Optics and Photonics courses in the recently established Centre for Teaching and Learning in the College of Physical Sciences at ANU.