A technology of laser-induced coloration of metals by surface oxidation is demonstrated. Each color of the oxide film corresponds to a technologic chromacity coefficient, which takes into account the temperature of the sample after exposure by sequence of laser pulses with nanosecond duration and effective time of action. The coefficient can be used for the calculation of laser exposure regimes for the development of a specific color on the metal. A correlation between the composition of the films obtained on the surface of stainless steel AISI 304 and commercial titanium Grade 2 and its color and chromacity coordinates is shown.

We have developed a novel nanophotonic design representing a plasmonic hybrid Au–Si nanosponge structure. The obtained results provide an understanding of the internal structure and physics of this hybrid nanosponge.

Counterfeiting is a severe problem of world economics and trade when non-authorized manufacturers produce and distribute various goods as products of famous brands. Many economic spheres from daily consumer goods and pharmaceuticals

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Fine control of the chiral light-matter interaction at the nanoscale, by exploiting designed metamaterial architecture, represents a cutting-edge craft in the field of biosensing, quantum, and classic nanophotonics. Recently, artificially engineered 3D nanohelices demonstrate programmable wide chiroptical properties by tuning materials and architecture, but fundamental diffractive aspects that are at the origin of chiral resonances still remain elusive. Here, a novel concept of a 3D chiral metacrystal, where the chiroptical properties are finely tuned by in-plane and out-of-plane diffractive coupling, is proposed. Different chiral dipolar modes can be excited along the helix arms, generating far field optical resonances and radiation pattern with in-plane side lobes, and suggesting that a combination of efficient dipole excitation and diffractive coupling matching controls the collective oscillations among the neighbor helices. The proposed concept of compact chiral metacrystal can be suitable for integration with quantum emitters and open perspectives in novel schemes of enantiomeric detection.