Abstract: A method for identifying a photoluminescent material that, after excitation with excitation light, emits emission light having different wavelengths is disclosed. The method includes irradiating the photoluminescent material with the excitation light, detecting a temporal intensity curve of at least two emission light components having different wavelengths, which components are emitted from the photoluminescent material as a result of the excitation, calculating initial intensities of the emission light components at a common time, determining at least one intensity parameter by correlating the calculated initial intensities, determining at least one decay parameter value for each of the emission light components from a time progression of their intensity and identifying the photoluminescent material using the intensity parameter(s) and the decay parameter values.

Abstract: A method for identifying a photoluminescent material that, after excitation with excitation light, emits emission light having different wavelengths is disclosed. The method includes irradiating the photoluminescent material with the excitation light, detecting a temporal intensity curve of at least two emission light components having different wavelengths, which components are emitted from the photoluminescent material as a result of the excitation, calculating initial intensities of the emission light components at a common time, determining at least one intensity parameter by correlating the calculated initial intensities, determining at least one decay parameter value for each of the emission light components from a time progression of their intensity and identifying the photoluminescent material using the intensity parameter(s) and the decay parameter values.

Abstract: An apparatus is disclosed for inspecting a surface containing a material that emits luminescent radiation in response to absorbing excitation radiation. The apparatus comprises a laser disposed in or adjacent to a housing. A sensor opening is defined in the housing and permits emission of excitation radiation generated by the laser and permits admission of the luminescent radiation emanating from the surface in response to the excitation radiation. A sensor monitors whether ambient light is being admitted between an edge of the sensor opening and the surface upon which the sensor opening is in contact. A safety circuit permits the laser to be actuated only when the sensor detects a substantially or completely light-impermeable contact between the edge of the sensor opening and the surface.