Dielectric particle-based strategy to design a new self-bending subwavelength structured light beams

During last 2 years it was shown that an electromagnetic field can be made to curve after propagation through a simple dielectric material of special shape, which adds a new-found degree of simplicity. This effect was termed 'photonic hooks' - it is a unique electromagnetic beam configuration behind a mesoscale dielectric 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 a new dielectric particle-based strategy to design selfbending subwavelength structured light beams

Photonic Jet with Tunable Focus Based on Water Droplets Freezing from the Outside In

Water droplets are a perspective highly abundant phase-change material to realize tunable optical lenses. We demonstrated for the first time that freezing mesoscale water droplet could be use as tunable optical lens, such that freezing becomes an asset despite both the low absolute values of the refractive indices of the shell and core materials and their optical contrast. It was shown that the dielectric shell of mesoscale water droplet in the form of solid ice allows controlling both the maximum field intensity and the focus position of the formed photonic nanojet. The formation of ice with air bubbles during the freezing of a water droplet is appropriate for a dynamic increase in the range of change of the focal position compared to solid ice. The proposed concept of a tunnelable spherical lens based on a freezing water drop can be used for microscopy, optical traping in "green" mesotronics.Comment: 8 pages, 5 figure

Magnetic hot-spots generation at optical frequencies in all-dielectric mesoscale Janus particles

At optical frequencies due to the small value of the magnetic permeability of natural materials, the magnetic effects are week. To this end, the natural dielectric materials are unemployable for practical magnetic applications in optics. We have shown that it is possible to induce the intense magnetic hot spots in a Janus dielectric mesoscale particle. The basic idea of the Janus particle based on a combination of the effects of a photonic jet, whispering gallery waves and the concept of solid immersion. Simulations show that H^2/E^2 contrast maybe more 10 and maximal magnetic field intensity enhancement is more than 1000 for a wavelength-scaled particle with refractive index less than 2.Comment: 11 pages, 9 figure

Future green technology: freezing water micro-droplet as an all-optical switch based on time domain photonic hook

Here we show that mesoscale freezing water droplet with low Bond number can behave as fully biocompatible natural microlenses to form the photonic hook in application to tunable optical switch. We first introduce and demonstrated the basic concepts of all-optical switch without changes in the wavelength of illumination of a particle or any moving parts involved. The principle of operation of the switch based on the temperature-induced phase change inside water droplet refractive index. Simulation shows that the optical isolation of switched channels for an optical switch with linear dimensions of about 15{\lambda}3, based on freezing water droplet, can reach 10 dB during the temperature variation at fixed wavelength. The freezing mesoscale droplets acting as time domain photonic hook generator open the intriguing route for full optical switching in a multifunctional green electronics tool for sensing, integrated optics and optical computers.Comment: 5 figures, 8 page