Focusing capability of integrated chains of microspheres in the limit of geometrical optics


Conference Paper

The effects of periodical focusing of light were studied in chains of sapphire microspheres with 300 μm diameters assembled either on a substrate or inside capillary tubing. Dye-doped fluorescent microspheres were used as multimodal sources of light in experimental studies. Significant reduction of the focused spot sizes was observed for chains of spheres compared to a single sphere case. Numerical ray tracing simulations were performed for similar chains assembled inside hollow waveguides to be used as an optical delivery system with mid-infrared lasers for ultra-precise surgery. The device designs were optimized for contact conditions during laser surgery involving short optical penetration depths of light in tissue. It is shown that chains of spheres with n around 1.65-1.75 provide a two-fold improvement of the spatial resolution over single spheres. Potential applications of these microprobes include ultraprecise laser procedures in the eye and brain or piercing a cell, and coupling of multimodal beams into photonic microstructures. © 2011 SPIE.

Full Text

Duke Authors

Cited Authors

  • Darafsheh, A; Allen, KW; Fardad, A; Fried, NM; Antoszyk, AN; Ying, HS; Astratov, VN

Published Date

  • April 22, 2011

Published In

Volume / Issue

  • 7913 /

International Standard Serial Number (ISSN)

  • 0277-786X

International Standard Book Number 13 (ISBN-13)

  • 9780819484505

Digital Object Identifier (DOI)

  • 10.1117/12.876139

Citation Source

  • Scopus