Polarization synthesis and sorting with an integrated silicon nanoantenna

We demonstrate the synthesis of any arbitrary polarization state of light, spanning the full Poincare sphere, radiated by a single silicon nanoantenna with two feeding waveguides. We experimentally demonstrate the synthesis of linearly, circularly and elliptically polarized light using this method. The reciprocal scenario allows the analysis of light impinging in the nanoantenna, sorting different linear incoming polarization components into different waveguides. Although the method is universal and can be extended to any wavelength and technology, we perform our demonstrations in a CMOS compatible silicon photonics platform, potentially allowing the fast electrical modulation of the amplitude and phase of conventional silicon waveguides to achieve a tuneable polarization synthesizer/analyser.