title: Generation of Aspherical Optical Lenses via Arrested Spreading and Pinching of a Cross-Linkable Liquid.
abstract: Aspherical optical lenses with spatially varying curvature are desired for capturing high quality, aberration free images in numerous optical applications. Conventionally such lenses are prepared by multistep top-down processes which are expensive, time-consuming, and prone to high failure rate. In this context, an alternate method is presented here based on arrested spreading of a sessile drop of a transparent, cross-linkable polymeric liquid on a solid substrate heated to an elevated temperature. Whereas surface tension driven flow tends to render it spherical, rapid cross-linking arrests such flow so that nonequilibrium aspherical shapes are attained. It is possible to tune also the initial state of the drop via delayed pinching of a liquid cylinder which precedes its release on the substrate. This method has led to the generation of a wide variety of optical lenses, ranging from spherical plano convex to superspherical solid immersion to exotic lenses not achieved via conventional methods.
authors.forename: Abhijit Chandra
authors.initials: AC
authors.lastname: Roy
authors.forename: Mridul
authors.initials: M
authors.lastname: Yadav
authors.affiliation: Central Electrochemical Research Institute, CECRI (CSIR) , Karaikudi, Sivaganga-630006, Tamil Nadu India.
authors.forename: Edward Peter
authors.initials: EP
authors.lastname: Arul
authors.affiliation: Department of Chemical Engineering, Manipal Institute of Technology , Manipal, 576104, Karnataka India.
authors.forename: Anubhav
authors.initials: A
authors.lastname: Khanna
authors.affiliation: INM-Leibniz Institute for New Materials and Saarland University , Campus D 2 2, 66123 Saarbrucken, Germany.
authors.forename: Animangsu
authors.initials: A
authors.lastname: Ghatak