We propose a simple and flexible fabrication approach based on the moiré effect of photoresist gratings for rapid synthesis of apodized structures with continuously varying depth. Minor modifications in a standard laser interference lithography setup allow creating macroscopic, visible by naked eye moiré patterns that modulate the depth of subwavelength diffraction gratings. The spatial frequency of this modulation is easily controlled in a wide range, allowing to create a quasicrystal in extreme cases. Experimental results are confirmed by a theory with clear graphical solutions and numerical modeling. The method is universal and does not depend on a specific choice of photoresist and/or substrate materials, making it a promising choice for structured light applications, optical security elements or as a basic structuring method of complex optical devices.

Due to their high refractive index, record optical anisotropy and a set of excitonic transitions in visible range at a room temperature, transition metal dichalcogenides have gained much attention. Here, we adapted a femtosecond laser ablation for the synthesis of WSe₂ nanoparticles (NPs) with diameters from 5 to 150 nm, which conserve the crystalline structure of the original bulk crystal. This method was chosen due to its inherently substrate-additive-free nature and a high output level. The obtained nanoparticles absorb light stronger than the bulk crystal thanks to the local field enhancement, and they have a much higher photothermal conversion than conventional Si nanospheres. The highly mobile colloidal state of produced NPs makes them flexible for further application-dependent manipulations, which we demonstrated by creating substrates for SERS sensors.

Transition metal dichalcogenides (TMDCs), belonging to the class of van der Waals materials, are promising materials for optoelectronics and photonics. In particular, their giant optical anisotropy may enable important optical effects when employed in nanostructures with finite thickness. In this paper, we theoretically and numerically study light scattering behavior from anisotropic $\mathrm{Mo}{\mathrm{S}}_2$ nanocylinders, and highlight its distinct features advantageous over the response of conventional silicon particles of the same shape. We establish two remarkable phenomena, appearing in the same $\mathrm{Mo}{\mathrm{S}}_2$ particle with optimized geometry. The first one is a pure magnetic dipole scattering associated with the excitation of the electric-dipole anapole states. Previously reported in core-shell hybrid (metal/dielectric) systems only, it is now demonstrated in an all-dielectric particle. The second phenomenon is the super deflection in the far-field: the maximum scattering may occur over a wide range of directions, including forward-, backward- and side-scattering depending on the mutual orientation of the $\mathrm{Mo}{\mathrm{S}}_2$ nanocylinder and the incident wave. In contrast to the well-known Kerker and anti-Kerker effects, which appear in nanoparticles at different frequencies, the super deflection can be achieved by rotating the particle at a constant frequency of incident light. Our results facilitate the development of functional optical devices incorporating nanostructured anisotropic TMDCs and may encourage further research in meta-optics based on highly anisotropic materials.

The article focuses on depth-dependent visible band transmission effects in a symmetrical “insulator-metal-insulator” diffraction system based on a variable depth grating. These effects were studied both experimentally and theoretically in TM and TE polarizations. In particular, the existence of an optimized grating depth for plasmon-mediated resonant transmission was confirmed experimentally, and differences in TE and TM transmission behavior are discussed. We utilize a simple and flexible fabrication approach for rapid synthesis of apodized structures with adiabatically varying depth based on a beat pattern of two interferential lithography exposures. The present study can be useful in the fields of transmission-based optical security elements and biosensors.