Abstract: Methods are provided for authenticating a value article that includes a luminescent material. An exciting light source, an optical filter, a photodetector, a signal manipulation circuit, and an amplifier are provided. The luminescent material is exposed to light produced by the exciting light source. Radiation including light from the exciting light source and emitted radiation from the luminescent material is filtered using the optical filter to produce filtered radiation. The filtered radiation is detected using the photodetector to produce a detected radiation signal. The detected radiation signal is electronically manipulated using the signal manipulation circuit to reduce an effect of light from the exciting light source on an authentication determination based upon the detected radiation signal. The detected radiation signal is amplified with the amplifier after electronic manipulation to produce an amplified electronic signal.

Abstract: Methods are provided for authenticating a value article that includes a luminescent material. An exciting light source, an optical filter, a photodetector, a signal manipulation circuit, and an amplifier are provided. The luminescent material is exposed to light produced by the exciting light source. Radiation including light from the exciting light source and emitted radiation from the luminescent material is filtered using the optical filter to produce filtered radiation. The filtered radiation is detected using the photodetector to produce a detected radiation signal. The detected radiation signal is electronically manipulated using the signal manipulation circuit to reduce an effect of light from the exciting light source on an authentication determination based upon the detected radiation signal. The detected radiation signal is amplified with the amplifier after electronic manipulation to produce an amplified electronic signal.

Abstract: Embodiments include methods and apparatus for identifying a thermographic phosphor (e.g., Er:YIG) incorporated on or within an article. The method and apparatus embodiments include an excitation energy generator selectively exposing the article to excitation energy in an absorption band of the thermographic phosphor. An emitted radiation detector detects first emission characteristics of first emitted radiation from the article within an emission band of the thermographic phosphor when the article has a first temperature, and detects second emission characteristics of second emitted radiation from the article within the emission band when the article has a second temperature that is different from the first temperature. A temperature adjustment element is configured to adjust the temperature of the article. Embodiments further include a processing system determining whether the first emission characteristics are sufficiently different from the second emission characteristics.