Glass Difractive Optical Elements (DOEs) with complex modulation DLC thin film coated

Sparvoli, Marina; Mansano, Ronaldo Domingues

doi:10.1590/s1516-14392008000300018

Cited by 3 publications

(1 citation statement)

References 16 publications

(18 reference statements)

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“…Optical diffusers are wavefront processors used to alter the intensity distribution of an incident light beam into a specified pattern. 1,2 They are widely used in imaging systems, LED displays, and barcode scanners to provide uniform light exposure and eliminate high-intensity spots. [3][4][5][6][7] Depending on the incorporated light scattering method, optical diffusers are classified as the volumetric or surface relief types.…”

Section: Introductionmentioning

confidence: 99%

Laser inscription of pseudorandom structures for microphotonic diffuser applications

et al. 2018

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Optical diffusers provide a solution for a variety of applications requiring a Gaussian intensity distribution including imaging systems, biomedical optics, and aerospace. Advances in laser ablation processes have allowed the rapid production of efficient optical diffusers. Here, we demonstrate a novel technique to fabricate high-quality glass optical diffusers with cost-efficiency using a continuous CO2 laser. Surface relief pseudorandom microstructures were patterned on both sides of the glass substrates. A numerical simulation of the temperature distribution showed that the CO2 laser drills a 137 μm hole in the glass for every 2 ms of processing time. FFT simulation was utilized to design predictable optical diffusers. The pseudorandom microstructures were characterized by optical microscopy, Raman spectroscopy, and angle-resolved spectroscopy to assess their chemical properties, optical scattering, transmittance, and polarization response. Increasing laser exposure and the number of diffusing surfaces enhanced the diffusion and homogenized the incident light. The recorded speckle pattern showed high contrast with sharp bright spot free diffusion in the far field view range (250 mm). A model of glass surface peeling was also developed to prevent its occurrence during the fabrication process. The demonstrated method provides an economical approach in fabricating optical glass diffusers in a controlled and predictable manner. The produced optical diffusers have application in fibre optics, LED systems, and spotlights.

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Section: Introductionmentioning

confidence: 99%

Laser inscription of pseudorandom structures for microphotonic diffuser applications

et al. 2018

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Computer-Generated Holograms Application in Security Printing

et al. 2022

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In the present article the application of computer-generated holograms in security printing was considered. The main subject was creation of informative memory marks based on CGH for automatic read out of the information embedded in this marks that can be used for identification, copyrighting, or other types of authentication control of security elements. The fundamental theoretical basics of computer-generated holograms and its applications were given. The proposed technical solutions, such as “Printed hologram”, “Smart verification”, and “Holomemory”, were considered in detail. The announced solutions were presented in the schemes of interaction between manufacturers of security printing and its potential consumers—citizens and regulatory government agencies.

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