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Basic Research of Intrinsic Tamper Indication Markings and Patterns Defined by Pulsed Laser Irradiation (Final Report)

Adams, David P.; Murphy, Ryan D.; Saiz, David J.; Yalisove, Steven M.; Bahr, David F.; Lawrence, Samantha K.; Moody, Neville R.; Neiser, Geneva; Sobczak, Catherine

Pulsed laser irradiation has been used to create complex, intrinsic markings that can be used as unique identifiers for authentication and asset protection. Markings have been made on the surface of various materials by rapidly scanning a focused laser beam across a designated area as large as several square inches. Markings include macro-scale patterns, such as barcodes, that contain encrypted information. More complex markings are comprised of macro-scale patterns and embedded, unique micro-scale features. Micro-scale features form spontaneously during scanned laser irradiation and have different shapes, spacings, color and other characteristics that are virtually impossible to recreate. The macro-scale patterns can be interrogated rapidly in the field using a digital camera, while the embedded micro-scale features are best evaluated in the laboratory using microscopy or related optical techniques. Interrogated markings are compared with archived maps of the original patterns (obtained at the time of their manufacture) to determine component authenticity. The majority of experiments have involved marking planar solids. A new instrument that marks non-planar substrates is described for future work.

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TYPE Other Report YEAR 2016
DOIOSTI

Laser Marking and Composition Analysis of 13-8 Steel and Nitronics 60 Surfaces

Murphy, Ryan D.; Saiz, David J.; Cruz-Cabrera, A.A.; Aragon, Phil R.; Rodriguez, Mark A.; Adams, David P.

Pulsed laser irradiation is used to irradiate and mark 13-8 steel and Nitronics 60 parts in order to create observable markings on the surfaces. The best optical contrast ratio between marked regions and unmarked regions is desired for digital image correlation. The contrast is optimized by using pulsed-laser irradiation and varying the laser power, pulse length, and scan speed. X-ray diffraction was used to characterize the laser-irradiated surface, and it was found that oxide formation and surface roughness are responsible for the observed contrast.

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TYPE SAND Report YEAR 2015
DOIOSTI
Results 51–73 of 73
Results 51–73 of 73