Arrays of evanescently coupled waveguides can be used to retrieve simultaneously the first-order correlation functions in multiple-field interferometry. Here it is shown that this remarkable property of waveguide arrays is enabled only by the existence of nonlocal interaction, i.e., non-nearest-neighbor coupling between the waveguides.
DOI:https://doi.org/10.1103/PhysRevA.92.013804
©2015 American Physical Society
(a) Cartoon illustrating the setup allowing the simultaneous retrieval of the field-correlation functions of four light fields injected in selected waveguides of a square array of coupled waveguides. The chosen numbering of the waveguides is overlaid. (b) Definition of the relevant coupling coefficients in a square array of waveguides.
Reuse & PermissionsBest condition number of the matrix as a function of the relative diagonal and vertical coupling strength.
Reuse & PermissionsHistograms of the intensity and phase of the -matrix elements (see text for details) for three different values of the diagonal coupling for a array excited in four different points (waveguides 4, 6, 20, and 22). The propagation length has been fixed to . As described in the labels, the condition number (CN) of the matrix decreases with increasing diagonal coupling.
Reuse & PermissionsHistograms of the intensity and phase of the -matrix elements (see text for details) for three different values of the diagonal coupling for a array excited in four different points (waveguides: 1, 2, 3, and 4). The propagation length has been fixed to . Also in this case, the condition number of the matrix is lower for larger diagonal coupling.
Reuse & PermissionsPhase of the output mode field for injection site 1 and observation sites 11–14. The insets represent the simulated configuration, as seen from the output facet of the array. Shaded waveguide: injection site. Black waveguide: observation site.
Reuse & PermissionsStatistical distribution of the condition number of a random matrix featuring 25 instances of interferometric four-field combination (equivalent to a waveguides beam combiner). The histogram results from 10000 random matrix realizations.
Reuse & Permissions
