Introduction.

The role of optics in sensing is obviously expanding; witness the large number of papers presented at the Annual Meeting of the Optical Society of America held in October 1998. From sensing inside the human body to sensing in outer space, every Technical Group within OSA had papers that highlighted some of the new technologies being employed in sensors and some of the applications for sensing. A look at a few of the titles of some of the symposia serves to illustrate the breadth of sensing within the optics community: Optical Sensors for Combustion Diagnostics, Polymer and Molecular Systems for Optical Sensing, Multidiscriminant/Multispectral/Polarization Imaging, Novel Imaging Techniques in Biomedicine, Nonlinear and Novel Imaging Techniques. The papers in the sessions ranged from discussions of basic physics to presentations of highly engineered applications. I see this as one of the very useful roles that conferences can serve - the interchange of information between those who emphasize component development and those who develop system requirements.