title: Optical microspherical resonators for biomedical sensing.
abstract: Optical resonators play an ubiquitous role in modern optics. A particular class of optical resonators is constituted by spherical dielectric structures, where optical rays are total internal reflected. Due to minimal reflection losses and to potentially very low material absorption, these guided modes, known as whispering gallery modes, can confer the resonator an exceptionally high quality factor Q, leading to high energy density, narrow resonant-wavelength lines and a lengthy cavity ringdown. These attractive characteristics make these miniaturized optical resonators especially suited as laser cavities and resonant filters, but also as very sensitive sensors. First, a brief analysis is presented of the characteristics of microspherical resonators, of their fabrication methods, and of the light coupling techniques. Then, we attempt to overview some of the recent advances in the development of microspherical biosensors, underlining a number of important applications in the biomedical field.
authors.affiliation: MDF Lab, Istituto di Fisica Applicata Nello Carrara (IFAC CNR), Via Madonna del Piano 10, 50019 Sesto Fiorentino, Firenze, Italy. s.soria@ifac.cnr.it
authors.forename: Silvia
authors.initials: S
authors.lastname: Soria
authors.forename: Simone
authors.initials: S
authors.lastname: Berneschi
authors.forename: Massimo
authors.initials: M
authors.lastname: Brenci
authors.forename: Franco
authors.initials: F
authors.lastname: Cosi
authors.forename: Gualtiero Nunzi
authors.initials: GN
authors.lastname: Conti
authors.forename: Stefano
authors.initials: S
authors.lastname: Pelli
authors.forename: Giancarlo C
authors.initials: GC
authors.lastname: Righini