BIDIMENSIONAL PLANAR MICROOPTICS FOR OPTOCHEMICAL ABSORBENCY SENSING

A new approach for developing optochemical absorbance sensors is prese nted. The method is based on a planar micro-optic circuit in which an optochemically active membrane that responds to selective compounds is deposited in the device, yielding a part of the guiding planar struct ure. In this way the optical field is confined in the direction transv erse to the substrate and controlled in the lateral direction by means of planar micro-optics components. High sensitivity of the device can be easily obtained because of the relatively long light paths through the membrane, and the response time is low because the analyte has to diffuse through a several-micrometer-thin membrane. Experimental resu lts of measurements of the concentration of potassium are also present ed to verify the possibilities of these devices as specific absorbance sensors. (C) 1998 Optical Society of America.