Techniques for high-speed scanning of free-space OCT devices

Summary form only given. We present results of OCT scans in layered materials and through coatings on wires. We show how this technique can be used to detect defects in insulators, coatings, and paints. We outline how novel, free-space, rapid-scanning techniques can be used to produce X-Z scans at speeds approaching video frame rates. We also discuss the use of our apparatus to study the birefringence produced by the subsurface region in various materials. Such birefringence can be used as a measure of internal material stresses.