Our long term goal is to develop a phantom for use in calibrating and measuring resolution of confocal microscopes using fiber optic technology. Modern microscopy is increasingly quantitative. Size of the observed objects is critical in a number of areas. Resolution is also a necessary parameter in many measurements, and that now includes resolution along the vertical dimension (axial depth into the sample) direction as well as lateral (in the image plane). Calibration of intensity completes the set of quantities needed to make it possible to compare measurements between microscopes or across time. In the reflectance mode this will be done by using different ranges of index differences. Glasses with fluorescent dopants can provide a calibratory for the confocal microscope (CFM) used in a fluorescent mode (now the most common mode in biologial studies). In this mode the calibratory can also be used to measure registration of the images obtained in two wavelength. This proposal is for the development of a calibration standard tool for all these quantities. We will use TaperVision expertise in fiberoptics technology to achieve the necessary dimensions and tolerances for such a measurement tool. The phase I proposal is to evaluate the feasibility of generating such a calibrating target in the right parameters and to show that intensity calibration and fluorescent mode devices can also be constructed using the same basic technology. POTENTIAL COMMERCIAL APPLICATION: The calibrator will be used by developers and users of CFM's to verify performance and to obtain measurements. There are currently 5000 CFM's on the market and their number and applications are expected to rise sharply.