Observation of edge-to-edge topological transport in a photonic lattice

The edge-to-edge topological transport of the one-dimensional odd-sized Su-Schrieffer-Heeger model plays a crucial role in robust energy transfer and information processing. However, it has not been verified experimentally. Here we report on an experimental demonstration of this topological transport in a one-dimensional photonic lattice of coupled waveguides. When slowly varying the spacings of the adjacent waveguides, the robust topological transport of light from the leftmost to the rightmost channels has been successfully observed. Moreover, the transport speed and efficiency of light are enhanced considerably by introducing the exponential-type modulations of the coupling strengths. The experimental results agree well with analytical calculations and numerical simulations. This transport of light observed may serve as the basis for photonic devices of unconventional functions.