OPTIMIZED TRANSITION OF A GUIDE IN A CLADDING

摘要

The invention concerns an optical device comprising in a substrate of refractive index n<SUB>1</SUB>, an optical guide of index n<SUB>2</SUB>, an optical cladding of index n<SUB>3</SUB> independent of the guide and enclosing a portion of said guide in a zone of the substrate called interaction zone, said guide and said cladding being obtained by treating parts of the substrate through ion exchange technique. It further comprises a zone, called transition zone, located at the interface of the substrate and the cladding on the guide path, said zone accompanying the penetration of the guide into the substrate or into the cladding as the case may be, said zone having a refractive index which is gradually adapted over a determined minimum length so as to reduce the difference of index when the guide passes from the substrate to the cladding and/or from the cladding to the substrate. The invention also concerns a method for making said device including the following steps: a) providing a substrate wherein the device will be produced, b) introducing a first ionic species into the substrate to enable the optical cladding to be produced after step e), c) introducing a second ionic species into the substrate to enable the transition zone to be produced after step e), d) introducing a third ionic species into the substrate to enable the guide to be produced after step e), e) burying the ions introduced at steps b, c, and d) to produce the cladding, the transition zone and the guide.