Sorting linearly polarized photons with a single scatterer

This paper was published in OPTICS LETTERS and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://dx.doi.org/10.1364/OL.39.001394. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under lawIntuitively, light impinging on a spatially mirror-symmetric object will be scattered equally into mirror-symmetric directions. This intuition can fail at the nanoscale if the polarization of the incoming light is properly tailored, as long as mirror symmetry is broken in the axes perpendicular to both the incident wave vector and the remaining mirror-symmetric direction. The unidirectional excitation of plasmonic modes using circularly polarized light has been recently demonstrated. Here, we generalize this concept and show that linearly polarized photons impinging on a single spatially symmetric scatterer created in a silicon waveguide are guided into a certain direction of the waveguide depending exclusively on their polarization angle and the structure asymmetry. Our work broadens the scope of polarization-induced directionality beyond plasmonics, with applications in polarization (de)multiplexing, unidirectional coupling, directional switching, radiation polarization control, and polarization-encoded quantum information processing in photonic integrated circuitsThis work has received financial support from the Spanish government (contracts Consolider EMET CSD2008-00066 and TEC2011-28664-C02-02) and GV (grant ACOMP/2013/013). F. J. R.-F. acknowledges support from grant FPI of GV. D. Puerto acknowledges support from grant Juan de la Cierva (JCI-2010-07479).Rodríguez Fortuño, FJ.; Puerto García, D.; Griol Barres, A.; Bellieres, LC.; Martí Sendra, J.; Martínez Abietar, AJ. (2014). Sorting linearly polarized photons with a single scatterer. Optics Letters. 39(6):1394-1397. doi:10.1364/OL.39.001394S1394139739