Optical sensors have many applications in R&D, national defense and commercial markets such as medical diagnostics and process control. But because of the breadth of applications for optical sensors, the challenges to the design and functioning of an optical sensor for a particular application requires knowledge of optical, material, and environmental properties that affect sensor performance. SENSORS addresses all aspects of optical sensors from source and detection technologies, sensor configurations, and processing approaches to applications. These optical sensors range from micro-probes to large devices used for standoff monitoring of industrial and environmental species.