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

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

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

IOP PUBLISHING LTD

Año: 2015

1464-4258

In this work we present a new approach related to the profile reconstruction of graded-indexQ2 waveguides, based on the inversion of the Helmholtz equation for TE propagation modes frommeasuring the near field. We used the scalar approximation, but we also consider the evanescentfield as key experimental data to be acquired and analyzed. From this, it is possible to obtain abetter fitting of the real low-contrast waveguide index profile and get more importantinformation, allowing us to determine at the same time the effective index and the shape of theguidance cross section. Compared with experimental data, it could be possible, in a selfconsistentway, to enhance the accuracy of the retrieval information corresponding to thetransversal shape of these kinds of waveguides. This procedure also allows us to obtain aneffective and absolute refractive index profile instead of the relative determinations that areusually reported in the literature.