Microsphere-chain waveguides: Focusing and transport properties
Abstract
It is shown that the focusing properties of polystyrene microsphere-chain waveguides (MCWs) formed by sufficiently large spheres (D ≥ 20λ, where D is the sphere diameter and λ is the wavelength of light) scale with the sphere diameter as predicted by geometrical optics. However, this scaling behavior does not hold for mesoscale MCWs with D ≤ 10λ resulting in a periodical focusing with gradually reducing beam waists and in extremely small propagation losses. The observed effects are related to properties of nanojet-induced and periodically focused modes in such structures. The results can be used for developing focusing microprobes, laser scalpels, and polarization filters.
- Publication:
-
Applied Physics Letters
- Pub Date:
- July 2014
- DOI:
- 10.1063/1.4890595
- Bibcode:
- 2014ApPhL.105b1112A