Schulz, J.J.SchulzJörg, C.C.JörgFreymann, Georg vonGeorg vonFreymann2022-10-072022-10-072022https://publica.fraunhofer.de/handle/publica/42741510.1364/OE.4479212-s2.0-8512629463435299400We experimentally demonstrate that the next-nearest-neighbor-coupling (NNN-coupling) in an array of waveguides can naturally be negative. To do so, dielectric zig-zag shaped waveguide arrays are fabricated with direct laser writing (DLW). By changing the angle of the zig-zag shape it is possible to tune between positive and negative ratios of nearest and next-nearest-neighbor coupling, which also allows to reduce the impact of the NNN-coupling to zero at the correct respective angle. We confirm the existence of negative NNN-couplings experimentally and show the improved accuracy of a refined tight-binding model. Our results are also of importance for other discrete systems in which the tight-binding model is often used.enjournal article