Dr. Juan Cabanillas
Funding : Ministerio de Ciencia e Innovación. TEC2010-21830-C02-02
Duration: 2011 - 2013
Conjugated polymers have several properties which makes them highly suitable for optical sensing. Examples are high photoluminescence quantum yield in solid state, notable optical gain properties, exciton diffusion lengths exceeding 10 nm and ease of processing into waveguides and laser resonators. Exploiting ASE emission of conjugated polymers in waveguides for sensing has the advantage of increasing the sensitivity to fluorescence quenchers compared to conventional fluorescent sensors since non linear emission is dramatically reduced by their presence at the polymer surface. In this project we develop rib planar waveguides based on polyfluorene with widths comprised between 20 and 200 μm and 800 nm height. Typical analytes targeted are NO2 and amines. Capping of the polymer waveguide with monolayers of photoactive molecules is investigated as a way to fine tune the sensitivity and selectivity of the waveguide sensor.
Figure (from left to right): Topography image of 100 μm waveguide ribs. ASE emission characteristics as
a function of excitation fluence.