We demonstrated an effective magnetic field for light using an on-chip Ramsey-type interferometer. A superposition of ground and excited photonic states in waveguides allows for non-reciprocal phase shifts, which we achieved using electro-optic modulation of the silicon waveguides.
Just as wavelength-division multiplexing revolutionized telecommunications, multiplexing using the spatial modes of light promises to offer significant capacity boosts to optical waveguides. We demonstrated selective excitation of higher-order modes in silicon waveguides, allowing multi-dimensional bandwidth scaling.
Some of our work, in collaboration with Prof. Keren Bergman at Columbia University, is on network applications of our silicon devices such as high speed data transmission and switching using non-blocking filters.