Faceted gratings for an optical security feature
| Autor: | Yoran Eli Pigeon, Qiang Song, Kevin Heggarty |
|---|---|
| Přispěvatelé: | Department of Physics, University of British Columbia (UBC), Département Optique (IMT Atlantique - OPT), IMT Atlantique Bretagne-Pays de la Loire (IMT Atlantique), Institut Mines-Télécom [Paris] (IMT)-Institut Mines-Télécom [Paris] (IMT) |
| Rok vydání: | 2020 |
| Předmět: |
Diffraction
Computer science Physics::Optics Grating Diffraction efficiency 01 natural sciences law.invention 010309 optics Optics law 0103 physical sciences Blazed grating Electrical and Electronic Engineering [SPI.NANO]Engineering Sciences [physics]/Micro and nanotechnologies/Microelectronics Engineering (miscellaneous) Lithography Diffractive optics Diode business.industry Micro optics Atomic and Molecular Physics and Optics [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism Harmonic [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic Light shaping Photo-Lithography Photolithography business [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing |
| Zdroj: | Applied Optics Applied optics Applied optics, Optical Society of America, 2020, 59 (4), pp.910. ⟨10.1364/AO.378122⟩ |
| ISSN: | 1539-4522 0003-6935 |
| DOI: | 10.1364/ao.378122 |
| Popis: | International audience; A method of optimizing and manufacturing a diffractive blazed grating array (DBA) is proposed to create a visual security feature when illuminated by a divergent Light emitting diode (LED) source. A pure phase grating array serving as the optical security component consists of blazed grating cells with the same size of 75μm. After a divergent spherical wave is decomposed into harmonic-waves, each grating cell of the DBA deflects locally the harmonic-waves into predefined directions and forms a feature pattern on the target plane. Particularly, a two-step optimization method is further developed for optimizing the period and orientation of each grating cell. The DBA sample is fabricated by using our home-built parallel direct-write photo-plotter with a resolution of 0.75 μm. Both numerical simulations and optical experiments are demonstrated to validate the proposed model. Since the optical security component developed is a surface relief structure of a single polymer material, it can be replicated for mass production by using standard roll to roll nano-imprint technology. This design algorithm proposed in this work will enable the extension of the optical security elements to a broader realm and facilitate extensive developments in other research fields of the optics community, such as light shaping, specific illumination for lithography and microscope systems. |
| Databáze: | OpenAIRE |
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