Controllable optical Zitterbewegung in PT-symmetric photonic lattices

We present that parity-time-symmetric photonic lattices can support optical Zitterbewegung (ZB) motion with controllable oscillation amplitude. The nonorthogonality of the Floquet–Bloch modes imposed by the non-Hermitian nature of the dynamics substantially affects the wave oscillation dynamics. It is shown that the amplitude of this optical ZB depends on the gain parameter, thus allowing to control the ZB process. The non-reciprocal light propagation induced by the nonorthogonality of the modes can balance the spectral angular broadening of the incident beam and even the strong oscillations with slightly growing amplitude along the propagation can be observed. Robustness of the optical ZB phenomenon to the perturbations of the gain parameter is also demonstrated.