Polymorphic gallium for active resonance tuning in photonic nanostructures: from bulk gallium to two-dimensional (2D) gallenene
Reconfigurable plasmonics is driving an extensive quest for active materials that can support a controllable modulation of their optical properties for dynamically tunable plasmonic structures. Here, polymorphic gallium (Ga) is demonstrated to be a very …
Room temperature wideband tunable photoluminescence of pulsed thermally annealed layered black phosphorus
Newly explored two-dimensional (2D) materials have shown promising optical properties, owning to the tunable band gap of the layered material with its thickness. A widely used method to achieve tunable light emission (or photoluminescence) is through …
Black phosphorus (BP)–graphene guided-wave surface plasmon resonance (GWSPR) biosensor
Due to lower out-of-plane electrical conductance, black phosphorus (BP) provides a suitable host material for improving the sensitivity of biosensors. However, BP oxidizes easily, which limits practical applications. In this article, we propose a …
Gain-induced scattering anomalies of diffractive metasurfaces
Photonic nanostructures with gain and loss have long been of interest in the context of diverse scattering anomalies and light-shaping phenomena. Here, we investigate the scattering coefficients of simple gain-doped diffractive metasurfaces, revealing pairs …
Role of hot electron scattering in epsilon-near-zero optical nonlinearity
The physical origin of epsilon-near-zero (ENZ) optical nonlinearity lies in the hot-electron dynamics, in which electron scattering plays an important role. With the damping factor defined by hot electron scattering time, the Drude model could be extended to …
Palladium diselenide as a direct absorption saturable absorber for ultrafast mode-locked operations: from all anomalous dispersion to all normal dispersion
Layered transition metal dichalcogenides with excellent nonlinear absorption properties have shown remarkable performance in acting as ultrafast photonics devices. In our work, palladium diselenide (PdSe2) nanosheets with competitive advantages of wide …
Selective surface-enhanced Raman scattering in a bulk nanoplasmonic Bi2O3-Ag eutectic composite
A recent surge of interest in surface-enhanced Raman scattering (SERS) has stimulated the search for new systems that can be utilized to fabricate high-performance optical devices. However, the two-dimensional design of the vast majority of SERS-based …
Spheroidal trap shell beyond diffraction limit induced by nonlinear effects in femtosecond laser trapping
Beyond diffraction limit, multitrapping of nanoparticles is important in numerous scientific fields, including biophysics, materials science and quantum optics. Here, we demonstrate the 3-dimensional (3D) shell-like structure of optical trapping well induced …
Titanium dioxide metasurface manipulating high-efficiency and broadband photonic spin Hall effect in visible regime
The interactions of photonic spin angular momentum and orbital angular momentum, i.e., the spin-orbit coupling in focused beams, evanescent waves or artificial photonic structures, have attracted intensive investigations for the unusual fundamental phenomena …
Enhanced directional emission of monolayer tungsten disulfide (WS2) with robust linear polarization via one-dimensional photonic crystal (PhC) slab
Monolayer transition metal dichalcogenides (TMDCs) have been regarded as promising candidates for the future light-emitting devices. To date, though the modulation of emission intensity and directionality in monolayer TMDCs has received considerable scholarly …
Thermoelectric nanospectroscopy for the imaging of molecular fingerprints
We present a nanospectroscopic device platform allowing simple and spatially resolved thermoelectric detection of molecular fingerprints of soft materials. Our technique makes use of a locally generated thermal gradient converted into a thermoelectric …
Demonstration of biaxially tensile-strained Ge/SiGe multiple quantum well (MQW) electroabsorption modulators with low polarization dependence
We demonstrate a novel biaxially tensile-strained Ge/SiGe multiple quantum well (MQW) electroabsorption modulator with low polarization dependence. The device is waveguide integrated and has a length of 900 ?m. Suspended microbridge structure is utilized to …
On-chip arbitrary-mode spot size conversion
Manipulating on-chip optical modes via components in analogy with free-space devices provides intuitional light control, and this concept has been adopted to implement single-lens–assisted spot size conversion using integrated device. However, the reported …
Bound states in the continuum (BIC) accompanied by avoided crossings in leaky-mode photonic lattices
When two nonorthogonal resonances are coupled to the same radiation channel, avoided crossing arises and a bound state in the continuum (BIC) appears with appropriate conditions in parametric space. This paper presents numerical and analytical results on the …