Thermally tunable polarization by nanoparticle plasmonic resonance in photonic crystal fibers

A photonic crystal fiber selectively filled with silver nanoparticles dispersed in polydimethylsiloxane has been numerically studied via finite elements analysis. These nanoparticles possess a localized surface plasmon resonance in the visible region which depends on the refractive index of the surrounding medium. The refractive index of polydimethylsiloxane can be thermally tuned leading to the design of polarization tunable filters. Filters found with this setup show anisotropic attenuation of the x-polarization fundamental mode around alfax = 1200dB/cm remarkably higher than the y-polarization mode. Moreover, high fiber birefringence and birefringence reversal is observed in the spectral region of the plasmon.Authors are grateful for financial support from Programa RETOS of the Spanish Ministerio de Economía y Competitividad ( TEC2013-47342-C2), the regional R&D Program SINFOTON of the Comunidad de Madrid ( SINFOTON S2013/MIT-2790) and European COST Action ( IC1208