This project will demonstrate a new class of optical devices that will form the heart of a low cost, versatile, field usable environmental monitoring system to be developed in Phase II. Specifically, Physical Optics Corporation will fabricate and test a solid state filter tailored to precisely match the spectral characteristics of target compound(s), either gaseous or liquid, in the near infrared region of the electromagnetic spectrum. The filter will be easy to mass produce, small, and quite durable, and it will be capable of having its optical spectrum modulated in a straightforward, cost effective, way. The use of such novel devices will allow the near infrared `overtone` optical absorbance bands of many gases of environmental and industrial importance, including so called `greenhouse effect gases` and primary air pollutants, to be monitored remotely with rugged, compact systems either in situ or remotely via optical fibers. These detectors will have the extremely high specificity and sensitivity of systems based on modulation/correlation spectroscopy but without the need for expensive wavelength tunable laser diodes or bulky `reference cells` filled with target compounds. Chemical detectors based on tailored modulatable solid state filters will be of great commercial value in remote monitoring of environmental contaminants, chemical process control, oil exploration, mine safety, and other applications where high sensitivity detection of target compounds must be accomplished under less than ideal conditions. Tailored filters can also be used for a wide variety of other applications, from instrument calibration to custom illumination.
