The development of shift-free fixed-line filters is a key technology for advancing the next generation of laser protection and is greatly desired due to the increased threat of laser attacks. Thin-film interference coatings have remained the key technology for achieving narrow bandstop filters for protection against laser light since the late 1970s. This paper presents the latest developments in fixed-line laser technology and introduces a metamaterial solution to mitigate the angular shift found in thin-film interference coatings. The metamaterial coating consists of metallic nano-particles periodically distributed within a non-absorbing dielectric material with a specific refractive index that enables the desired plasmonic resonance to exist at wavelengths that match that of the lasers. Due to the nano-particle size, the metamaterial layer can be treated as an individual homogeneous layer with properties described by an effective Drude-Lorentz approximation model. Unlike standard interference coatings where the effective index of the stack decreases with larger angles of incidence, the metamaterial’s effective index remains relatively fixed with increasing angles resulting in the narrow bandstop function remaining shift-free.
During last several years it was shown, that an electromagnetic field can be made to curve after propagation through a simple dielectric mesoscale Janus particle of special shape, which adds a newfound degree of simplicity. This effect was discovered by I.V.Minin and O.V.Minin and termed ‘photonic hooks’– it is an unique electromagnetic self-bending subwavelength structured light beams configuration behind a mesoscale particle with a broken symmetry and differ from Airy-family beams. PH features the radius of curvature, which is about 2 times smaller than the electromagnetic wavelength - this is the smallest curvature radius of electromagnetic waves ever reported. The nature of a photonic hook is in dispersion of the phase velocity of the waves inside of particle, resulting in interference. Here, we report an experimental verification of the photonic hook effect in terahertz waveband.
Ablation with nanoscale spatial resolution needs special tools to overcome conventional diffraction limit. A few methods
have been successfully applied for this purpose. These include: surface nanostructuring by laser illuminated tip; Near-field
Scanning Optical Microscopy (NSOM) nano-patterning; Surface nano-processing based on optical resonances and
near-field effects with transparent particles as well as the field enhancement by plasmonic nanoparticles. All these
methods permit localized laser ablation on the scale beyond 100 nm. In this paper we report our recent work related to
field enhancement by laser illuminated tip, near-field laser ablation with transparent particles and field enhancement by