Subsurface Defect Detection in Ceramic Materials Using Low Coherence OpticalScatter Reflectometer

摘要

We demonstrate the use of optical gating techniques for determining the size andlocation of subsurface defects in advanced ceramic materials. Various silicon nitride based ceramic materials are probed non-destructively using an optical gated reflectometer based on a low-coherence fiber interferometer. This device is capable of depth and lateral resolutions of 10 micrometers and 4 micrometers, respectively. Experimental results indicate that the size and position of small subsurface defects can be determined as deep as 500 micrometers below the surface.