The Boeing Company
Active real-time characterization system for identifying surface contamination

Abstract:

An active real-time characterization system for identifying the presence of surface contaminants on to an outer surface of an article under test. Infrared and visible light sources controllably output a beam of coherent light directed at a particular area on the article under test, the infrared light source having an optical parametric oscillator coupled to an optical parametric amplifier. A series of cameras, including a visible light camera, a visible light second harmonic generation camera, an infrared camera, an infrared second harmonic generation camera, a sum-frequency camera and a third-order camera each include an associated filter system and are each configured to receive return beams of light at predetermined frequencies controlled by the filter system. A processor determines whether the received signals have a spectral response that is different from a baseline spectral response thereby indicating that contaminants exist on the surface of the article under test.