Color-changing refractive index sensor based on Fano-resonant filtering of optical modes in a porous dielectric Fabry-Pérot microcavity
Abstract
Refractometry is a ubiquitous technique for process control and substance identification in the chemical and biomedical fields. Herein, we present an all-dielectric, wafer-scalable, and compact Fabry-Pérot microcavity (FPMC) device for refractive index (RI) sensing. The FPMC consists of a highly porous SiO2 microcavity capped with a thin, quasi-periodically patterned TiO2 hole array partial reflector that enables rapid, nanoliter-scale analyte transport to and from the sensor. Liquid (alcohols) or condensed-vapor (water from human breath) infiltration resulted in spectral redshifts up to 100 nm, highly apparent visible color change, rapid recovery (2 outcoupling layer effectively filter higher-order Fabry-Pérot cavity modes and thereby confer an easily identifiable red-to-green color transition during analyte infiltration.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Sep 09, 2020
- Source ID
- 10.1364/oe.403506
Entities
People
- Helen Stute
- Michael Gordon
- N. Isaac Zakaria
- Pavel Shapturenka
- Steven P. DenBaars
Organizations
- Army Research Office
- Solid State Lighting and Energy Electronics Center, University of California Santa Barbara