Shai Maayani

Rashba-type plasmonic metasurface

Observation of the plasmonic Rashba effect manifested by a polarization helicity degeneracy removal in a surface wave excitation via an inversion asymmetric metamaterial is reported. By designing the metasurface symmetry using anisotropic nanoantennas with space-variant orientations, we govern the light-matter interaction via the local field distribution arising in a wavelength and a photon spin control. The broken spatial inversion symmetry is experimentally manifested by a directional excitation of surface wave jets observed via a decoupling slit as well as by the quantum dot fluorescence. Rashba-type plasmonic metasurfaces provide a route for spin-based nanoscale devices controlled by the metamaterial symmetry and usher in a new era of light manipulation.

Water-walled microfluidics for high-optical finesse cavities

In submerged microcavities there is a tradeoff between resonant enhancement for spatial water and light overlap. Why not transform the continuously resonating optical mode to be fully contained in a water microdroplet per se? Here we demonstrate a sustainable 30-μm-pure water device, bounded almost completely by free surfaces, enabling >1,000,000 re-circulations of light. The droplets survive for >16 h using a technique that is based on a nano-water bridge from the droplet to a distant reservoir to compensate for evaporation. More than enabling a nearly-perfect optical overlap with water, atomic-level surface smoothness that minimizes scattering loss, and ∼99% coupling efficiency from a standard fibre. Surface tension in our droplet is 8,000 times stronger than gravity, suggesting a new class of devices with water-made walls, for new fields of study including opto-capillaries.

Regular oscillations and random motion of glass microspheres levitated by a single optical beam in air.

We experimentally report on optical binding of many glass particles in air that levitate in a single optical beam. A diversity of particle sizes and shapes interact at long range in a single Gaussian beam. Our system dynamics span from oscillatory to random and dimensionality ranges from 1 to 3D. The low loss for the center of mass motion of the beads could allow this system to serve as a standard many body testbed, similar to what is done today with atoms, but at the mesoscopic scale.

Light and Capillary Waves Propagation in Water Fibers

The confinement of light and sound, while they are traveling in fibers, enables a variety of light-matter interactions. Therefore, it is natural to ask if fibers can also host capillary waves. Capillary waves are similar to those we see when throwing a stone into a puddle. Such capillary waves are prohibited in microfluidic devices where the liquid is bounded by solid walls. In contrast, we have fabricated fibers, which are made entirely from water and are suspended in air. The water fiber can therefore move, e.g. in a resonant mode that reassembles the motion of a guitar string. In our experiment, light guided through the water fiber allows optical interrogation of is capillary oscillations. Co-confining two important oscillations in nature: capillary and electromagnetic, might allow a new type of devices called Micro-Electro-Capillary-Systems [MECS]. The softness of MECS is a million times higher when compared to what the current solid-based technology permits, which accordingly improves MECS response to minute forces such as small changes in acceleration. Additionally, MECS might allow new ways to optically interrogate viscosity and surface tension, as well as their changes caused by introducing an analyte into the system.

Regular oscillations and random motion of glass microspheres levitated by a single optical beam in air: publisher's note.

This publishers note amends a recent publication [Opt. Express24(3), 2850-2857 (2016)] to include Acknowledgments.

Liquid-walled optical MEMS

We demonstrate a new type of optical MEMS that is having most of its walls made of liquids. Examples include (1) experimental demonstration of water-walled microfluidic devices with optical finesse over a million as well as (2) cavity optomechanics at 40 MHz vibrational rates in a droplet of oil.