Tortora, P.Abashin, M.Märki, I.Nakagawa, W.Vaccaro, L.Salt, M.Herzig, H. P.Levy, U.Fainman, S.Fainman, Y.2013-01-172013-01-172013-01-17200510.1364/OL.30.002885https://infoscience.epfl.ch/handle/20.500.14299/87917We apply heterodyne scanning near-field optical microscopy (SNOM) to observe with subwavelength resolution the amplitude and phase of optical fields propagating in several microfabricated waveguide devices operating around the 1.55 mu m wavelength. Good agreement between the SNOM measurements and predicted optical mode propagation characteristics in standard ridge waveguides demonstrates the validity of the method. In situ observation of the subwavelength-scale distribution and propagation of optical fields in straight and 90 degrees bend photonic crystal waveguides facilitates a more detailed understanding of the optical performance characteristics of these devices and illustrates the usefulness of the technique for investigating nanostructured photonic devices.Near-field microscopyphotonic crystal waveguideObservation of amplitude and phase in ridge and photonic crystal waveguides operating at 1.55 μm by use of heterodyne scanning near-field optical microscopytext::journal::journal article::research article