Abstract

We report on the first experimental investigation [1-2] of light propagation around defects in parity-time (PT) symmetric photonic lattices. An extended PT mesh lattice, as depicted in Fig. 1a, is realized using a setup consisting of two coupled fiber loops with different lengths (Fig. 1b) and time dependent modulation of net gain/loss. Time-multiplexing is applied to map a 1D grid of transverse positions into the temporal domain thus transferring concepts of PT symmetric systems to pulse propagation [3]. To guide bound light modes through this mesh lattice, we introduce a phase defect φ_d which occupies a single site in the periodic lattice.

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