Surface plasmon chemical/biological sensor in integrated optics

A small and efficient chemical/biological sensor can be realized by the use of surface plasmon resonance in integrated optics. The attenuation coeffic ient of the device is modified by the presence of a sensitive material whos e index and/or thickness depends on the concentration in certain molecules that are characteristic of it. A modal analysis of the sensor structure is performed and a very simple model is proposed to assist in the structure de sign and optimization. Finally, some experimental results for gas detection are presented. (C) 1998 Elsevier Science S.A. All rights reserved.