Recently, a type of curved light beams, photonic hooks (PHs), was theoretically predicted and experimentally observed. The production of photonic hook (PH) is due to the breaking of structural symmetry of a plane-wave illuminated microparticle. Herein, we presented and implemented a new approach, of utilizing the symmetry-broken of the microparticles in material composition, for the generation of PHs from Janus microcylinders. Finite element method based numerical simulation and energy flow diagram represented theoretical analysis were used to investigate the field distribution characteristics and formation mechanism of the PHs. The full width at half-maximum (FWHM) of the PH (~0.29λ) is smaller than the FWHM of the photonic nanojet (~0.35λ) formed from a circular microcylinder with the same geometric radius. By changing the refractive index contrasts between upper and lower half-cylinders, or rotating the Janus microcylinder relative to the central axis, the shape profiles of the PHs can be efficiently modulated. The tunability of the PHs through simple stretching or compression operations, for the Janus microcylinder constituted by one solid inorganic halfcylinder and the other flexible polymer half-cylinder, was studied and discussed as well.

In order to meet the demand for highly integrated terahertz chips with ultra-low transmission loss, a novel hybrid graphene plasmonic waveguide is proposed, wherein low-index insulators are embedded between a slot-rib (covered by graphene) structure and a high-index dielectric waveguide. This designed waveguide combines the plasmonic response of graphene, energy distribution mechanism of materials with large refractive index difference, and modal properties of hybrid plasmonic waveguide to yield superior waveguiding performance. We achieved 50 times stronger mode confinement along with five times smaller propagation loss, as compared to the traditional graphene hybrid plasmonic waveguide operating at 3 THz. Investigation on the influence of modal properties on chemical potential of graphene revealed an active approach to control mode confinement or propagation distance. In addition, owing to the ultra-strong energy confinement of modes, the crosstalk caused by coupling between two parallel waveguides is negligible, which paves the way for realizing ultra-compact, chip-level terahertz devices.

Antimony (Sb), a typical group VA semimetal, has rarely been studied both experimentally and theoretically in plasmonic photothermal therapy, possibly due to the lack of effective morphology‐controllable methods for the preparation of high‐quality Sb nanocrystals. In this study, an effective ligand‐guided growth strategy to controllably synthesize Sb nanopolyhedrons (Sb NPHs) with ultrahigh photothermal conversion efficiency (PTCE), good photothermal stability, as well as biocompatibility is presented. Furthermore, the modulation effect of different morphologies on localized surface plasmon resonance (LSPR) of Sb NPHs in experimentation is successfully observed. When the resonance frequency of the Sb NPHs is matched well with the excitation wavelength (808 nm), the PTCE of the Sb NPHs is as high as 62.1%, which is noticeably higher compared to most of the reported photothermal agents. The Sb NPHs also exhibit good photothermal stability. In addition, Sb‐NPHs‐based multifunctional nanomedicines are further constructed via loading 1‐methyl‐d‐tryptophan on PEGylated Sb NPHs for a highly efficient photoacoustic‐imaging‐guided synergistic photothermal/immune‐therapy of tumors in vivo. This work can stimulate further theoretical and experimental investigations of Sb NPHs and other semimetal nanomaterials regarding their LSPR properties and inspire various potential applications of semimetals in biomedicine and sensors.

The ever-increasing demand for faster speed, broader bandwidth, and lower energy consumption of on-chip processing has motivated the use of light instead of electrons in functional communication components.

A fiber loop mirror (FLM) filter with two-stage polarization-maintaining fibers (PMFs) and polarization controllers (PCs) is presented. The transmission function of this FLM is calculated in detail by Jones matrix. The wavelength interval depends on both the PMFs and the PCs. The side frequencies can be restrained by choosing appropriate length of the PMFs. Furthermore, an erbium-doped fiber ring laser based on this FLM filter is proposed and demonstrated. Stable single-, double- and triple-wavelength are achieved respectively. The 3 dB line-width is less than 0.03 nm, and the fluctuation of wavelength and peak power is less than 0.05 nm and 0.1 dB in 30 minutes.