title: Characterization of microstructures fabricated by two-photon polymerization using coherent anti-stokes Raman scattering microscopy.
abstract: We demonstrate the possibility to image microstructures fabricated by two-photon polymerization (TPP) using coherent anti-Stokes Raman scattering (CARS) microscopy. The imaging contrast based on chemical selectivity attained by CARS microscopy is used to gather qualitative information on TPP. Upon the basis of detailed knowledge of the characteristic signatures of the photoresist Raman spectrum, quantitative relationships between laser writing conditions and polymer cross-linking are demonstrated. The increase in degree of polymer conversion as a function of laser average power follows a sigmoidal profile which is interpreted in terms of a simple model based on the polymerization mechanism of the photoresist.
authors.affiliation: Technology and Applications Center, Newport Corporation, Irvine, California 92606, USA. tommaso.baldacchini@newport.com
authors.forename: Tommaso
authors.initials: T
authors.lastname: Baldacchini
authors.forename: Maxwell
authors.initials: M
authors.lastname: Zimmerley
authors.forename: Chun-Hung
authors.initials: CH
authors.lastname: Kuo
authors.forename: Eric O
authors.initials: EO
authors.lastname: Potma
authors.forename: Ruben
authors.initials: R
authors.lastname: Zadoyan