Wavepacket Self-imaging and Giant Recombinations via Stable Bloch-Zener Oscillations in Photonic Lattices with Local ${\cal PT}$-Symmetry

摘要

We propose a family of {\it local} $\cal{PT}$-symmetric photonic latticeswith transverse index gradient $\omega$, where the emergence of {\it stable}Bloch-Zener oscillations are controlled by the degree of non-Hermiticity$\gamma$ of the lattice. In the exact $\cal{PT}$-symmetric phase we identify acondition between $\omega$ and $\gamma$ for which a wavepacket self -imagingtogether with a cascade of splittings and giant recombinations occurs atvarious propagation distances. The giant wavepacket recombination is furtherenhanced by introducing local impurities.