Unique property of microsphere resonator arrays is connected with a possibility to pre-select size-matched cavities with the standard deviation of spheres' diameters ~10-4. In such practically indistinguishable classical "photonic atoms" the individual whispering gallery modes (WGMs) can be strongly coupled leading to applications in slow-light devices, filters, array-resonator LEDs, and sensors. Along with the WGM-based coupling effects such arrays have very interesting nonresonant properties due to periodical focusing of light. The focused beams with subwavelength dimensions termed "nanoscale photonic jets" and corresponding quasi-periodic "nanojet-induced modes" can be obtained in such structures. In this presentation we review the technology, optical properties, and applications of microsphere resonator arrays.

Vasily Astratov is an associate professor in the Department of Physics and Optical Science at the University of North Carolina-Charlotte, joining the faculty in 2002. He received his Ph.D. degree from the A.F. Ioffe Physical-Technical Institute, St. Petersburg, Russia, in 1986. In 1993-1997 he headed a research group at the Ioffe Institute where he pioneered studies of opal photonic crystals. In 1997-2001 he has been a postdoctoral scholar at the University of Sheffield, UK, working on microcavities, photonic crystals, and opals. He is a topical editor for the journal Optics Express since 2005. He has served as a technical committee member for CLEO/QELS 2006-07, ICTON 2007-09, and OECC/ ACOFT 08. He has been a member of the international DFG panel on photonic crystals in Germany in 2000-05 and a member of the NSF panels on photonic devices and technology in 2004-08. He is a recipient of a number of awards including Senior Visiting EPSRC Fellow Award in the UK in 2006 and Award of the Exchange Program adopted between Royal Society and Russian Academy of Sciences in 1996. He is a co-author of over 100 publications cited over 2000 times. His current research is devoted to synthesis, optical characterization, and modeling of mesoscale photonics structures.