Low contrast buried waveguides index profile reconstruction method considering the evanescent field

D. BIASETTI; M.R. TEJERINA; G.A. TORCHIA

JOURNAL OF OPTICS. A, PURE AND APPLIED OPTICS (PRINT)

IOP PUBLISHING LTD

Lugar: Londres; Año: 2015 vol. 17 p. 85801 - 85807

1464-4258

In this work wepresent a new approach related to the profile reconstruction of graded-indexwaveguides, based on the inversion of the Helmholtz equation for TE propagationmodes from measuring the near field. We used the scalar approximation but wealso consider the evanescent field as key experimental data to be acquired andanalyzed. From this, it is possible to obtain a better fitting of the real lowcontrast waveguides index profile, and get more important information allowingus to determine at the same time the effective index and the shape of theguidance cross-section.Comparedwith experimental data, it could be possible, in a self-consistent way, toenhance the accuracy of the retrieval  information corresponding to the transversal shape of these kinds ofwaveguides. This procedure also allows us to obtain an effective and absoluterefractive index profile, instead of the relative determinations that areusually reported in the literature.