Fluorophore-doped xerogel antiresonant reflecting optical waveguides

A. Llobera, V. J. Cadarso, E. Carregal-Romero, J. Brugger, C. Domínguez, C. Fernández-Sanchez

Research output: Contribution to journalArticleResearchpeer-review

3 Citations (Scopus)


Rhodamine B and Alexa Fluor 430 fluorophores have been used as doping agents for xerogel waveguides defined over an antiresonant (ARROW) filter. This configuration has a significant level of integration, since it merges the waveguide, the light emitter and the filter in a single photonic element. Different technologies have been combined for their implementation, namely soft lithography, standard silicon-based technology and silicon bulk micromachining The spectral response of 15-mm long waveguides without fluorophore is first analyzed as a function of the waveguide width. Here, it has been observed how the xerogel used has a high transparency in the visible spectra, having only significant absorption at the wavelength where the ARROW filter is in resonance. In a second step, identical waveguides but doped with two different concentrations of Rhodamine B and Alexa Fluor 430 are studied. In addition to the effect of the filter, fluorophore-doped xerogel waveguides show losses close to-2 dB (equivalent to 2 dB of light emission). In addition, it has been observed how an increase of the fluorophore concentration within the xerogel matrix does not provide with a emission increase, but saturation or even a decrease of this magnitude due to self-absorption Finally, the total losses of the proposed waveguides are analyzed as a function of their width obtaining losses close to 5 dB for waveguide widths higher than 50 μm. 

Original languageEnglish
Pages (from-to)5026-5039
Number of pages14
JournalOptics Express
Issue number6
Publication statusPublished - 14 Mar 2011
Externally publishedYes

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