Biocompatible dually reinforced gellan gum hydrogels with selective antibacterial activity.

The poor mechanics and functionality of natural-polymer hydrogels from gellan gum (GG) prohibit their practical application, despite the intrinsic thermo-reversible gelation nature, structural and quality consistency, biocompatibility, biodegradability and sustainability of microbial fermentation-produced GG. Herein, a dual-reinforcing strategy, i.e.

Design and Analysis of a Large Mode Field Area and Low Bending Loss Multi-Cladding Fiber with Comb-Index Core and Gradient-Refractive Index Ring.

The large mode field area fiber can raise the tolerance of power, and high requirements for the bending characteristics of optical fibers are needed. In this paper, a fiber composed of a comb-index core, gradient-refractive index ring, and multi-cladding is proposed. The performance of the proposed fiber is investigated by using a finite element method at a 1550 nm wavelength.

Light Management With Grating Structures in Optoelectronic Devices.

Ordered and patterned micro/nanostructure arrays have emerged as powerful platforms for optoelectronic devices due to their unique ordered-dependent optical properties. Among various structures, grating structure is widely applied because of its simple fabrication process, easy adjusting of size and morph, and efficient light trapping. Herein, we summarized recent developments of light management with grating structures in optoelectronic devices.

Design and analysis of trench-assisted dual-mode multi-core fiber with large-mode-field-area.

A novel trench-assisted dual-mode multi-core fiber with large-mode-field-area is proposed. The structure consists of 17 conventional cores and two air holes according to a regular hexagon, which can realize strict dual-mode transmission. The structural parameters' effect on mode transmission characteristics, mode-field-area, and bending loss are analyzed systematically.

A Large Detection-Range Plasmonic Sensor Based on An H-Shaped Photonic Crystal Fiber.

An H-shaped photonic crystal fiber (PCF)-based surface plasmon resonance (SPR) sensor is proposed for detecting large refractive index (RI) range which can either be higher or lower than the RI of the fiber material used. The grooves of the H-shaped PCF as the sensing channels are coated with gold film and then brought into direct contact with the analyte, which not only reduces the complexity of the fabrication but also provides reusable capacity compared with other designs. The sensing performance of the proposed sensor is investigated by using the finite element method.

Broadband orbital angular momentum transmission using a hollow-core photonic bandgap fiber.

We present the viability of exploiting a current hollow-core photonic bandgap fiber (HC-PBGF) to support orbital angular momentum (OAM) states. The photonic bandgap intrinsically provides a large refractive index spacing for guiding light, leading to OAM transmission with low crosstalk. From numerical simulations, a broad OAM mode transmission window with satisfied effective index separations between vector modes (>10) and low confinement loss (<3  dB/km) covering 240 nm bandwidth is observed.

Analytical model for plasmon modes in graphene-coated nanowire.

An analytical model for plasmon modes in graphene-coated dielectric nanowire is presented. Plasmon modes could be classified by the azimuthal field distribution characterized by a phase factor exp(imφ) in the electromagnetic field expression and eigen equation of dispersion relation for plasmon modes is derived. The characteristic of plasmon modes could be tuned by changing nanowire radius, dielectric permittivity of nanowire and chemical potential of graphene.

Graphene-coated tapered nanowire infrared probe: a comparison with metal-coated probes.

We propose in this paper a graphene-coated tapered nanowire probe providing strong field enhancement in the infrared regimes. The analytical field distributions and characteristic equation of the supported surface plasmons mode are derived. Based on the adiabatic approximation, analytic methods are adopted in the investigation of field enhancement along the tapered region and show well consistence with the rigorous numerical simulations.