Efficient multiplexing and demultiplexing of free-space orbital angular momentum using a photonic integrated circuit

We present a silicon photonic integrated circuit for multiplexing and demultiplexing beams with orbital angular momentum into single-mode waveguides using a circular grating coupler fed by a star coupler. Experiments verify generation and sorting of nine azimuthally polarized OAM modes. © 2011 Optical Society of America OCIS codes: 060.2330 Fiber optics communications, 130.3120 Integrated optics devices.