Abstract

This paper investigates the non-Hermitian skin effect (NHSE) in dynamically modulated one-dimensional photonic lattices. We explore how periodic temporal modulation of the refractive index induces non-reciprocal hopping amplitudes, leading to the accumulation of a macroscopic number of eigenstates at the lattice boundary. Through a combination of theoretical analysis and numerical simulations, we demonstrate the emergence of the NHSE and its profound impact on light confinement and amplification. We further investigate the role of modulation parameters, such as frequency and amplitude, on the strength of the skin effect and the localization length of the confined modes. Our results reveal that the dynamically modulated photonic lattices provide a versatile platform for manipulating light propagation and offer novel opportunities for designing advanced photonic devices with tailored functionalities, including unidirectional waveguides, enhanced sensors, and compact optical amplifiers. Finally, we delve into the topological underpinnings of the observed phenomena, linking the NHSE to non-trivial winding numbers in the complex energy spectrum.