Active polarization independent coupling to silicon photonics circuit

We have experimentally demonstrated the ability to couple an arbitrary polarization state from a fiber to the TE-mode of a single waveguide in an integrated silicon photonics circuit with an extinction ratio larger than 31 dB, measured between the output ports of the integrated photonic circuit. To achieve this we combined a 2D- grating coupler and a Mach-Zehnder Interferometer (MZI). After accounting for setup and coupling losses, for a 1 mW input into the 2D coupler, we obtain an average output power of 0.98 mW at the desired waveguide, with less than 1.2 dB variation across all input polarization states. The experiments were performed at a wavelength of 1.55 μm.