Figure 3: Experimental results.
From: Exotic looped trajectories of photons in three-slit interference
(a–d) Measured interference patterns corresponding to the various probability terms in equation (3) (indicated as a label within each panel of the bottom). In this case the illumination field fills each arrangement of slits. The first row shows scanning electron microscope images of the slits used for the measurements, the scale bar represents 500 nm. The second and third panels show, respectively, the background-subtracted interference patterns formed when 60 frames, such as those in the insets are added, for the situations in which the probabilities of looped trajectories are negligible (using y-polarized illumination), and when such probabilities are increased due to the enhancement of near fields (using x-polarized illumination). Each of the frames shown in the insets was taken with an ICCD camera using heralded single-photons as a source. The bottom show the intensity dependence of the interference pattern measured along a horizontal line on the second and third panels. The ratio of the average probabilities obtained using x-polarized illumination to those obtained using y-polarized illumination, Px/Py, is shown at the bottom. All the measurements are conducted at a wavelength λ=810 nm, and using structures with dimensions w=200 nm, h=100 μm and p=4.6 μm
