Finding of the optimal parameters of animated and stereographic rainbow diffractive images

• Veröffentlicht in: Semiconductor Physics Quantum Electronics & Optoelectronics
• Datum: 2008
• Hauptverfasser: Borisov, I.S., Girnyk, V.I., Kostyukevych, S.A., Grygoruk, V.I., Kostyukevych, K.V.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: Інститут фізики напівпровідників імені В.Є. Лашкарьова НАН України 2008
• Online Zugang: https://nasplib.isofts.kiev.ua/handle/123456789/118852
• Назва журналу: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Zitieren: Finding of the optimal parameters of animated and stereographic rainbow diffractive images / I.S. Borisov, V.I. Girnyk, S.A. Kostyukevych, V.I. Grygoruk, K.V. Kostyukevych // Semiconductor Physics Quantum Electronics & Optoelectronics. — 2008. — Т. 11, № 2. — С. 178-187. — Бібліогр.: 11 назв. — англ.

We have considered the basic aspects of the technology of animated and
 stereographic rainbow images. These images can be included in Optical Security Devices
 (OSDs) in order to increase their structure complexity and to improve their protective
 properties. The cited technology provides, on the one hand, a simple identification on the
 visual level of verification and, on the other hand, the sufficient reliability against
 counterfeits. The last property is achieved at first by the division of the elemental unit on
 elemental regions of any adjusted shape with outline of the precision that is inaccessible
 for the recreation without Electron Beam Lithography Equipment (EBLE) which is used
 for the recording of OSDs. Second, the used encoding methods also assure the certain
 reliability.
 
 In the context of the paper, the theoretical discussion based a quantitative formulation of
 the Huygens--Fresnel law of the diffraction on an elemental diffractive grating is carried
 out. For other definite Conditions of Lighting and Observation of Diffracting Light
 (CLODL), the correlation between the slope angle of diffraction grating strokes and the
 corresponding horizontal parallax angle is got; and the parameter which defines the
 channel selection (the quality of splitting into separate channels) is introduced. The rule
 for the definition of the wavelength and the intensity of light that diffracts on a given
 grating under certain CLODL is derived as well. This fact allows one to create the
 software utility that models the behavior of anigrams or stereograms.
 An algorithm of the synthesis of anigrams and stereograms as parts of OSDs using the
 technology of a composite “figure” elemental unit (that is composed from parts of any
 shape) and applying the halftone encoding by the period, filling, and achromaticity or all
 these parameters at once is elaborated, and its software implementation is constructed.
 The criteria for the choice of such anigram’s parameters as the resolution, number of
 channels, and angle distances between them are elaborated. In order to check them, the
 results of tests are summarized. The investigation of the optimal parameters of halftone
 images’ encoding finding is implemented, and the results obtained for the tough and
 flexible linkings of a channel to the subregion of an elemental unit for hatching images
 are compared.