title: Tunable liquid microlens arrays in electrode-less configuration and their accurate characterization by interference microscopy.
abstract: A special class of tunable liquid microlenses is presented here. The microlenses are generated by an electrowetting effect under an electrode-less configuration and they exhibit two different regimes that are named here as separated lens regime (SLR) and wave-like lens regime (WLR). The lens effect is induced by the pyroelectricity of polar dielectric crystals, as was proved in principle in a previous work by the same authors (S. Grilli et al., Opt. Express 16, 8084, 2008). Compared to that work, the improvements to the experimental set-up and procedure allow to reveal the two lens regimes which exhibit different optical properties. A digital holography technique is used to reconstruct the transmitted wavefront during focusing and a focal length variation in the millimetre range is observed. The tunability of such microlenses could be of great interest to the field of micro-optics thanks to the possibility to achieve focus tuning without moving parts and thus favouring the miniaturization of the optical systems.
authors.affiliation: Istituto Nazionale di Ottica Applicata (CNR-INOA) & Istituto di Cibernetica del CNR E. Caianiello,Via Campi Flegrei 34 - 80078 Pozzuoli (NA), Italy.
authors.forename: L
authors.initials: L
authors.lastname: Miccio
authors.forename: A
authors.initials: A
authors.lastname: Finizio
authors.forename: S
authors.initials: S
authors.lastname: Grilli
authors.forename: V
authors.initials: V
authors.lastname: Vespini
authors.forename: M
authors.initials: M
authors.lastname: Paturzo
authors.forename: S
authors.initials: S
authors.lastname: De Nicola
authors.forename: Pietro
authors.initials: P
authors.lastname: Ferraro
mesh_terms: D017076:Computer-Aided Design; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006696:Holography / Q000295:instrumentation*; D007909:Lenses; D008859:Microscopy, Polarization / Q000379:methods*; D008904:Miniaturization; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012996:Solutions
chemical_list: D012996:Solutions