title: Reflectance-based two-dimensional TiO2 photonic crystal liquid sensors.
abstract: We propose and experimentally demonstrate a reflectance-based photonic crystal (PC) liquid sensor. The PC is made of two-dimensional TiO2 nanopillar arrays. Such a reflectance-based structure with large functional area not only simplifies the optical guiding but also enhances the sensor signal. A linear shift of reflectance peaks is found for liquids with refractive indices varying from 1.333 to 1.390 at wavelength near 1.5 μm. Excellent agreement between measured values and the generated reflectance model at a fixed wavelength is obtained, indicating the high potential of these PC-based liquid sensors for biological and environmental applications.
authors.affiliation: DIMES-ECTM, Delft University of Technology, Delft, The Netherlands. yujian.huang@tudelft.nl
authors.forename: Yujian
authors.initials: Y
authors.lastname: Huang
authors.forename: Grégory
authors.initials: G
authors.lastname: Pandraud
authors.forename: Pasqualina M
authors.initials: PM
authors.lastname: Sarro
mesh_terms: D002241:Carbohydrates / Q000032:analysis; D049329:Nanostructures; D055620:Optical Phenomena; D017785:Photons; D014025:Titanium
chemical_list: D002241:Carbohydrates; C009495:titanium dioxide; D014025:Titanium