Photonic signal transmitting device

Abstract

A photonic signal transmitting device comprising a first waveguide with a first core having a refractive index n1, and a second waveguide with a second core having an average refractive index n2>n1. The second core is formed with a transitional region having a refractive index that increases progressively, and the transitional region of the second core being in contact with the first core, either within or at the peripheral surface of the first core, whereby the refractive index in the device increases progressively from n1 to n2 with progression through the first to the second core. A contribution to the increase in refractive index from n1 to n2 may effectively be made by tapering the cross-sectional dimensions of the transitional region of the second core.

Dependencies are inferred from the claim text.