Development of an in-fiber nanocavity towards detection of volatile organic gases

A fiber optic sensor for Volatile Organic Compounds (VOCs) detection has been developed and characterized for some organic gasses. The sensor is based on a novel vapochromic material, which is able to change its optical properties in presence of organic vapors in a reversely way. A nano Fabry Perot is constructed onto a cleaved ended optical fiber pigtail by Electrostatic Self Assembly method (ESA), doping this structure with the vapochromic material. Employing a reflection scheme, a change in the intensity modulated reflected signal at 850 nm have been registered. The response of the sensor has been evaluated for five different VOCs, and a deeper study has been made for vapors of three different alcohols. This work was supported by Spanish Ministerio de Ciencia y Tecnología and FEDER Research Grants CICYT-TIC 2003-000909 and CICYT-TEC 2004-05936-C02-01/MIC.