title: Liquid crystal dynamics in a photonic crystal cavity created by selective microfluidic infiltration.
abstract: A microfluidic double heterostructure cavity is created in a silicon planar photonic crystal waveguide by selective infiltration of a liquid crystal. The spectral evolution of the cavity resonances probed by evanescent coupling reveals that the liquid crystal evaporates, even at room temperature, despite its relatively low vapor pressure of 5 × 10(-3) Pa. We explore the infiltration and evaporation dynamics of the liquid crystal within the cavity using a Fabry-Perot model that accounts for the joint effects of liquid volume reduction and cavity length variation due to liquid evaporation. While discussing how the pattern of the infiltrated liquid can be optimized to restrict evaporation, we find that the experimental behavior is consistent with basic microfluidic relations considering the small volumes of liquids and large surface areas present in our structure.
authors.affiliation: Centre for Ultrahigh Bandwidth Devices for Optical Systems (CUDOS), Institute of Photonics and Optical Science (IPOS), School of Physics, University of Sydney, New South Wales, Australia. casas@physics.usyd.edu.au
authors.forename: A
authors.initials: A
authors.lastname: Casas Bedoya
authors.forename: S
authors.initials: S
authors.lastname: Mahmoodian
authors.forename: C
authors.initials: C
authors.lastname: Monat
authors.forename: S
authors.initials: S
authors.lastname: Tomljenovic-Hanic
authors.forename: C
authors.initials: C
authors.lastname: Grillet
authors.forename: P
authors.initials: P
authors.lastname: Domachuk
authors.forename: E C
authors.initials: EC
authors.lastname: Mägi
authors.forename: B J
authors.initials: BJ
authors.lastname: Eggleton
authors.forename: R W
authors.initials: RW
authors.lastname: van der Heijden
mesh_terms: D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D050866:Liquid Crystals / Q000737:chemistry*; D044085:Microfluidics / Q000295:instrumentation*; D017785:Photons; D012031:Refractometry / Q000295:instrumentation*; D012825:Silicon / Q000737:chemistry*; D020349:Surface Plasmon Resonance / Q000295:instrumentation*
chemical_list: D012825:Silicon