A Waveguide Inline Binary Metasurface for Wavelength-Selective Transmission and Standing Wave Focusing.

This study presents an innovative inline metasurface design for selective wavelength transmission and focusing. When integrated into optical fibers, it improves the stability and compatibility with techniques like wavelength division multiplexing and phase modulation. Precise parameters, determined through analytical calculations and simulations, allow for the design of multifunctional lenses within the optical fiber platform.

Numerical Analysis of Protection Method of Metallic Sub-Wavelength Concentric Arrays for Radially Polarized Light Selection and Its Applications.

Radially polarized light has various advantages on sensing, thanks for its symmetric field distribution. To select radial component, metallic sub-wavelength concentric arrays are widely used. To increase the stability of the metallic nanostructure from mechanical or chemical hazards, a method to apply an additional protective layer has been proposed.

Numerical Study on Enhanced Line Focusing via Buried Metallic Nanowire Assisted Binary Plate.

Line focusing, which collects light into a line rather than a single point, has an advantage on variable fields such as machining and imaging. The 1-dimensional metallic zone plate is one of the candidates for line focusing, which is ultra-thin and simple to fabricate. Metallic nano-slits can replace the metal blocked region to increase the efficiency, however, the efficiency and stability are still low.

Compact micro-optic based components for hollow core fibers.

Using micro-optic collimator technology, we present compact, low-loss optical interconnection devices for hollow core fibers (HCFs). This approach is one of the key manufacturing platforms for commercially available fiber optic components and most forms of HCFs can readily be incorporated into this platform without the need for any substantial or complicated adaptation or physical deformation of the fiber structure. Furthermore, this technique can provide for very low Fresnel reflection interconnection between solid-core fiber and HCF and in addition provides a hermetic seal for HCFs, which can be a critical issue for many HCF applications.

Sub-wavelength annular-slit-assisted superoscillatory lens for longitudinally-polarized super-resolution focusing.

A binary metallic superoscillatory lens assisted with annular subwavelength slits is proposed, which generates a longitudinally-polarized super-resolution focal point. The annular slits are designed to selectively transmit radially-polarized light. Simulations using the finite element method show a 0.

Intermittent burst of a super rogue wave in the breathing multi-soliton regime of an anomalous fiber ring cavity.

We report the intermittent burst of a super rogue wave in the multi-soliton (MS) regime of an anomalous-dispersion fiber ring cavity. We exploit the spatio-temporal measurement technique to log and capture the shot-to-shot wave dynamics of various pulse events in the cavity, and obtain the corresponding intensity probability density function, which eventually unveils the inherent nature of the extreme events encompassed therein. In the breathing MS regime, a specific MS regime with heavy soliton population, the natural probability of pulse interaction among solitons and dispersive waves exponentially increases owing to the extraordinarily high soliton population density.

Metallic Fresnel zone plate implemented on an optical fiber facet for super-variable focusing of light.

We propose and investigate a metallic Fresnel zone plate (FZP/MFZP) implemented on a silver-coated optical fiber facet for super-variable focusing of light, the focal point of which can be drastically relocated by varying the wavelength of the incident light. We numerically show that when its nominal focal length is set to 20 μm at 550 nm, its effective focal length can be tuned by ~13.7 μm for 300-nm change in the visible wavelength range.

Corrugation-assisted metal-coated angled fiber facet for wavelength-dependent off-axis directional beaming.

We propose a fiber-optic-plasmonic hybrid device that is based on a corrugation-assisted metal-coated angled fiber facet (CA-MCAFF) for wavelength-dependent off-axis directional beaming (WODB). The device breaks into two key structures: One is the MCAFF structure, which is a modified Kretschmann configuration implemented onto a fiber platform, thereby being able to generate a unidirectional surface plasmon with dramatically enhanced properties in terms of non-confined diffracted radiation loss and operational bandwidth. The other is the periodic corrugation structure put on the MCAFF, thereby enabling WODB functionality out of the whole structures.

Numerical study on multi-pulse dynamics and shot-to-shot coherence property in quasi-mode-locked regimes of a highly-pumped anomalous dispersion fiber ring cavity.

We numerically investigate quasi-mode-locked (QML) multi-pulse dynamics in a fiber ring laser cavity in the anomalous dispersion regime. We show that the laser cavity can operate in five constitutively different QML regimes, depending on the saturation power of the saturable absorber element and the length of the passive fiber section that parameterize the overall nonlinearity and dispersion characteristic of the laser cavity. We classify them into the incoherent noise-like-pulse, partially-coherent noise-like-pulse, symbiotic, partially-coherent multi-soliton, and coherent multi-soliton regimes, accounting for their coherence and multi-pulse formation features.

Theoretical study on the generation of a low-noise plasmonic hotspot by means of a trench-assisted circular nano-slit.

We propose a novel trench-assisted circular metal nano-slit (CMNS) structure implementable on a fiber platform for the generation of a low-noise cylindrical surface plasmon (CSP) hotspot. We design trench structures based on a multi-pole cancellation method in order that a converging surface plasmon signal is well separated from co-propagating non-confined diffracted light (NCDL) at the hotspot location. In fact, the secondary radiation by the quasi-pole oscillation at the edge of the trench cancels the primary NCDL, thereby enhancing the signal-to-noise ratio (SNR) of the CSP hotspot.

Simple and reliable light launch from a conventional single-mode fiber into a helical-core fiber through an adiabatically tapered splice.

We propose a simple and efficient light launch scheme for a helical-core fiber (HCF) by using an adiabatically tapered splice technique, through which we overcome its inherent difficulty with light launch owing to the large lateral offset and angular tilt of its core. We experimentally demonstrate single-mode excitation in the HCF in this configuration, which yields the coupling efficiency of around -5.9 dB (26%) for a ~1.