Ultra-sensitive nanometric flat laser prints for binocular stereoscopic image.

Two-dimensional (2D) transition metal dichalcogenides (TMDs) with tantalizing layer-dependent electronic and optical properties have emerged as a paradigm for integrated flat opto-electronic devices, but their widespread applications are hampered by challenges in deterministic fabrication with demanded shapes and thicknesses, as well as light field manipulation in such atomic-thick layers with negligible thicknesses compared to the wavelength. Here we demonstrate ultra-sensitive light field manipulation in full visible ranges based on MoS laser prints exfoliated with nanometric precisions. The nontrivial interfacial phase shifts stemming from the unique dispersion of MoS layers integrated on the metallic substrate empower an ultra-sensitive resonance manipulation up to 13.

π-phase modulated monolayer supercritical lens.

The emerging monolayer transition metal dichalcogenides have provided an unprecedented material platform for miniaturized opto-electronic devices with integrated functionalities. Although excitonic light-matter interactions associated with their direct bandgaps have received tremendous research efforts, wavefront engineering is less appreciated due to the suppressed phase accumulation effects resulting from the vanishingly small thicknesses. By introducing loss-assisted singular phase behaviour near the critical coupling point, we demonstrate that integration of monolayer MoS on a planar ZnO/Si substrate, approaching the physical thickness limit of the material, enables a π phase jump.

Atomically Thin Noble Metal Dichalcogenides for Phase-Regulated Meta-optics.

Owing to its good air stability and high refractive index, two-dimensional (2D) noble metal dichalcogenide shows intriguing potential for versatile flat optics applications. However, light field manipulation at the atomic scale is conventionally considered unattainable because the small thickness and intrinsic losses of 2D materials completely suppress both resonances and phase accumulation effects. Here, we demonstrate that losses of structured atomically thick PtSe films integrated on top of a uniform substrate can be utilized to create the spots of critical coupling, enabling singular phase behaviors with a remarkable π phase jump.

Unidirectional Enhanced Dipolar Emission with an Individual Dielectric Nanoantenna.

Light manipulation at the nanoscale is the vanguard of plasmonics. Controlling light radiation into a desired direction in parallel with high optical signal enhancement is still a challenge for designing ultracompact nanoantennas far below subwavelength dimensions. Here, we theoretically demonstrate the unidirectional emissions from a local nanoemitter coupled to a hybrid nanoantenna consisting of a plasmonic dipole antenna and an individual silicon nanorod.

Bidirectional plasmonic coloration with gold nanoparticles by wavelength-switched photoredox reaction.

Reversible tuning of localized plasmon resonance that is supported by nanometric-sized metal particles holds potentially huge benefits in terms of manipulating light for widespread photonic applications. Although the practice of altering the frequency and the amplitude of plasmon resonance on gold nanoparticles is relatively well established, dynamic tuning by all-optical approaches for coloration has long been hindered due to limited implementation approaches with which gold nanomaterials can be photosynthetically manipulated. Here, we develop a wavelength-switched photoredox approach and demonstrate bidirectional tuning of the plasmonic resonance of crystalline gold nanoparticles for reversible surface-plasmon-resonance-based coloration.

Laser-Splashed Three-Dimensional Plasmonic Nanovolcanoes for Steganography in Angular Anisotropy.

Planar optics constructed from subwavelength artificial atoms have been suggested as a route to the physical realization of steganography with controlled intrinsic redundancy at single-pixel levels. Unfortunately, two-dimensional geometries with uniform flat profiles offer limited structural redundancy and make it difficult to create advanced crypto-information in multiplexed physical divisions. Here, we reveal that splashing three-dimensional (3D) plasmonic nanovolcanoes could allow for a steganographic strategy in angular anisotropy, with high resolution, full coloration, and transient control of structural profiles.

A fiber-optic sensor for neurotransmitters with ultralow concentration: near-infrared plasmonic electromagnetic field enhancement using raspberry-like meso-SiO nanospheres.

The feasibility of a localized surface plasmon resonance (LSPR) enhanced sensor based on raspberry-like nanosphere functionalized silica microfibers has been proposed and experimentally demonstrated. The extinction of single Ag (or Au) nanoparticles usually occurs at visible wavelengths. Nevertheless, a LSPR enhancement at near infrared wavelengths has been achieved by constructing raspberry-like meso-SiO nanospheres with noble metal nanoparticle cluster coating.

Optoplasmonic probe to realize scanning near-field Raman microscopy.

Tip-enhanced Raman spectroscopy (TERS) is a powerful scanning probe technique for Raman detections in nanotechnology to date. However, limited by the physical principles of a nanosize tapered metal (or metal-coated) probe used in a TERS device, only far-field without near-field Raman signal can be collected by the TERS with the metal probe. This makes conventional TERS lower in efficiency and cannot be a real near-field Raman microscopy.

Pure magnetic resonances controlled by the relative azimuth angle between meta-atoms.

A plasmonic molecule showing strong magnetic resonance modes and flexible tunability is proposed. The molecule is composed of two elements, a crescent shaped metallic disk and a smaller one embedded in the cavity of the larger one. The cavity and gap formed by these two elements enable the molecule to support magnetic resonances in the visible and near infrared spectral region, while electric resonances are much weaker to be detected.