Filtering of radially polarized beams by microsphere-chain waveguides

It is shown that microsphere-chain waveguides have strong polarization-dependent attenuation properties that can be used for developing passive filters of radially polarized beams. By using numerical modeling, it is demonstrated that the principle of operation of such devices is based on filtering periodically focused modes in chains of dielectric spheres occurring for a narrow range of indices of refraction 1.7<n<1.8. It is shown that for 10- and 20-sphere long chains a degree of radial polarization in excess of 0.8 and 0.9, respectively, can be obtained that allows developing novel polarization components with the light focusing capability.