Vol. 39, Issue 3, pp. 445-458 (2009)

Abstract

The paper presents an analysis of self-imaging phenomena in gradient multimode interference (MMI) structures produced by K⁺–Na⁺ ion exchange in glass. This investigation concerned curved MMI structures with various geometries – for the linear, concave function described by an exponential function, and the convex structure connected with a cosine course. The relations derived characterizing the relative shortening of the length of propagation for N-fold images have been confirmed by numerical simulations using the beam propagation method (BPM) of symmetrically excited gradient splitters 1×2.