Abstract: An authenticating pattern 20 for valuable objects is fabricated as an integrated structure of a substrate layer 21 and a transparent overcoat layer 22 with a viewable interface therebetween containing a light diffracting structure 10. Unique parameters are randomly defined in the light diffracting structure by anisotropic process steps not under full control of the producer during the manufacturing of the diffracting structure to prevent copying or creating an exact replica thereof. The resultant uniquely colored authenticating pattern can be verified by simple observation with the naked eye which is a prerequisite for ubiquitous verification.

Abstract: An authenticating pattern 20 for valuable objects is fabricated as an integrated structure of a substrate layer 21 and a transparent overcoat layer 22 with a viewable interface therebetween containing a light diffracting structure 10. Unique parameters are randomly defined in the light diffracting structure by anisotropic process steps not under full control of the producer during the manufacturing of the diffracting structure to prevent copying or creating an exact replica thereof. The resultant uniquely coloured authenticating pattern can be verified by simple observation with the naked eye which is a prerequisite for ubiquitous verification.

Abstract: A light diffracting structure 10 in an authenticating pattern 20 especially for an authentication label 30 is used for authenticating and protecting against forgery various valuable objects. The light diffracting structure 10 has unique parameters generating a uniquely colored pattern. The unique parameters are randomly defined by anisotropic process steps during the manufacturing of the diffracting structure and are not under full control of the producer. This prevents copying or creating an exact replica thereof. The authenticating pattern 20 comprises an integrated structure of a substrate layer 21 and a transparent overcoat layer 22 and the viewable interface therebetween includes the light diffracting structure 10. The uniquely colored authenticating pattern can be verified by simple observation with the naked eye which is a prerequisite for ubiquitous verification.

Abstract: In an optical storage system where an information bearing surface moves relative to a read/write head the latter includes a transparent body in which light beams sent to and from the surface are guided by multiple internal reflections. Beam shaping and focussing is effected by optical elements integrated in the surface of the body at the locations where the internal reflections occur. A distortion free imaging system is obtained with two series-arranged aspheric reflection surfaces which focus the beam on the information bearing surface. The separation of the input and the reflected beam paths is achieved with a polarizing beam splitter and an associated quarter-wave layer. For readout of a magneto-optic information bearing surface a nonperfect polarizing beam splitter is used in connection with a differential detection scheme to increase the signal to noise/ratio.

Abstract: The local state of polarization of a light wave field is determined by measuring the radiation transmitted by one or several polarizers with three different azimuth angles. A modified TV camera is used having its usually provided tri-color filters replaced by polarization filters whose azimuth angles differ from each other by 60.degree. respectively. On a connected color monitor, the local polarization state can be concluded from the local brightness, the hue, and the saturation. The polarization camera can preferably be used for ellipsometric measurings, in an interferometric system for surface topography, and in interferometric holography. The display of the polarization state of the color monitor can be supplemented by electronic means, e.g. emphasizing points having the same state of polarization.