Bill Baloukas

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In order to increase the anticounterfeiting performance of interference security image structures, we propose to implement an active component using an electrochromic material. This novel device, based on metamerism, offers the possibility of creating various surprising optical effects, it is more challenging to duplicate due to its complexity, and it adds(More)
This work presents a straightforward approach to determine the percolation threshold of silver thin films deposited by magnetron sputtering on various oxide layers at room temperature. The proposed method is based on the observation of the coupling of p-polarized light with local surface plasmons. By measuring the first Stokes parameter in real time, one(More)
Mechanical and thermoelastic properties of optical films are very important to ensure the performance of optical interference filters and optical coating systems. We systematically study the growth and the mechanical and thermoelastic characteristics of niobium oxide (Nb(2)O(5)), tantalum oxide (Ta(2)O(5)), and silicon dioxide (SiO(2)) thin films prepared(More)
Optical security devices applied to banknotes and other documents are exposed to different types of harsh environments involving the cycling of temperature, humidity, chemical agents, and tribomechanical intrusion. In the present work, we study the stability of optically variable devices, namely metameric interference filters, prepared by dual ion beam(More)
New security devices based on innovative technologies and ideas are essential in order to limit counterfeiting's profound impact on our economy and society. Interference security image structures have been in circulation for more than 20 years, but commercially available iridescent products now represent a potential threat. Therefore, the introduction of(More)
Electrochromic (EC) smart windows are able to decrease our energy footprint while enhancing indoor comfort and convenience. However, the limited durability of these windows, as well as their cost, result in hampered market introduction. Here, we investigate thin films of the most widely studied EC material, WO3. Specifically, we combine optical measurements(More)
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