STTR Phase I: Gabor-domain optical coherence microscopy for detection of defects in manufacturing

This Small Business Technology Transfer Phase I project will explore the applicability of a Gabor-domain optical coherence microscopy (GD-OCM) instrument to qualify materials during manufacturing processes. State-of-the-art interferometric instruments yield excellent resolution in depth, discriminating between different layers within a volume; optical microscopy offers high lateral resolution, but cannot characterize the features that are beneath the surface of the sample. GD-OCM offers the potential of combining the advantages of these two technologies - interferometry and microscopy - to produce unparalleled three-dimensional resolution throughout the volume of the sample. The primary objective of this effort will be the demonstration of a robust and accurate GD-OCM instrument for use in subsurface imaging and detection of defects in manufactured materials. During the project, this instrument will also be tested on various materials, including multilayered, in order to demonstrate its effectiveness and versatility in the acquisition of near-real-time information for use in guiding the optimization of manufacturing parameters for optimal and repeatable outcomes. The research will address the need for a rapid and robust scanning mechanism, compactly integrated within the optical microscope, to sample three-dimensional volumes and quantify undesired defects and imperfections introduced during the manufacturing of materials. The broader impact/commercial potential of this project is to effectively provide information about product quality during the manufacturing process of materials, including layered materials, through a robust and reliable instrument to be used in industrial environments. An industrial-class high-resolution GD-OCM system will enable manufacturers of materials (e.g. polymers, layered glass, reinforced composites, and advanced textiles) to optimize the fabrication parameters, improving the yield of their products. The application of GD-OCM has proven to be especially valuable to manufacturers of optical materials, such as spherical gradient refractive index (S-GRIN) polymers and layered optical structures -- including beaded and prismatic retroreflective films -- that are otherwise impossible to characterize nondestructively. GD-OCM will also enable new advances in a wide variety of scientific fields by offering the capability to image and optically section material samples without destroying them. This will offer new insight into the study of materials needed to advance tissue engineering and agricultural disease management, in addition to high-performance films and layered materials for other applications.