We have measured the photonic bandstructure of GaAs photonic-crystalwaveguides with high energy and momentum resolution using near-fieldscanning optical microscopy. Intriguingly, we observe additional bandsthat are not predicted by eigenmode solvers, as was recentlydemonstrated by Huisman et al. [Phys. Rev. B 86, 155154 (2012)]. Westudy the presence of these additional bands by performing measurementsof these bands while varying the incident light power, revealing anon-linear power dependence. Here, we demonstrate experimentally andtheoretically that the observed additional bands are caused by awaveguide-specific near- field tip effect not previously reported, whichcan significantly phase-modulate the detected field.

http://arxiv.org/abs/1410.1285

A. Singh, G. Ctistis, S. R. Huisman, J. P. Korterik, A. P. Mosk, J. L. Herek, P.W.H. Pinkse

2015

01/2015

J. Appl. Phys.

117

033104: 1-XX

Near-Field optical microscopy, Photonic crystal waveguide