Optical waveguide beam splitters based on hybrid metal–dielectric–semiconductor nanostructures

Abstract

Optical waveguide beam splitter Surface plasmons Interference Light spot Numerical simulation a b s t r a c t Miniature integration is desirable for the future photonics circuit. Low-dimensional semiconductor and metal nanostructures is the potential building blocks in compact photonic circuits for their unique electronic and optical properties. In this work, a hybrid metal-dielectric-semiconductor nanostructure is designed and fabricated to realizing a nano-scale optical waveguide beam splitter, which is constructed with the sandwiched structure of a single CdS nanoribbon/HfO 2 thin film/Au nanodisk arrays. Microoptical investigations reveal that the guided light outputting at the terminal end of the CdS ribbon is well separated into several light spots. Numerical simulations further demonstrate that the beam splitting mechanism is attributed to the strong electromagnetic coupling between the Au nanodisks and light guided in the nanoribbon. The number of the split beams (light spots) at the terminal end of the nanoribbon is mainly determined by the number of the Au nanodisk rows, as well as the distance of the blank region between the nanodisks array and the end of the CdS ribbon, owing to the interference between the split beams. These optical beam splitters may find potential applications in high-density integrated photonic circuits and systems.

Supramolecular Polymer-Based Fluorescent Microfibers for Switchable Optical Waveguides

“…Preparation of Fluorescent Microfibers Based on Supramolecular Polymer of bisP5A and GD. The supramolecular polymers are formed by the strong host− guest interaction of the pillar [5]arene (a kind of recently developed macrocyclic hosts, showing versatile complexation properties and wide potential applications 43−51 )-based host molecule bisP5A and guest molecule GD embodied a pair of cyanoalkyl triazoles whose binding constant toward pillar [5]arene is 1.2 × 10 4 M −1 in CHCl 3 . 52,53 The supramolecular polymerization is confirmed by diffusion-ordered 1 H NMR spectroscopy (DOSY) (Figure S1a) and viscometry (Figure S1b).…”

“…GD is a diphenylanthracene derivative and possesses characteristic photophysics with absorbance at 378 nm and fluorescence at 425 nm in CHCl 3 (Figure S2). Most aggregated diphenylanthracenes are vulnerable to photoluminescence quenching; however, the aggregated assemblies of GD and bisP5A show strong emissive owing to the steric bulk of pillar [5]arene. 53 The fibers also demonstrate intense blue emission under UV irradiation (Figure 1d).…”

“…We used the bisP5A, GDTE, and GD with a ratio of 1.25:0.25:1.0 in mole to prepare nanoparticles by the microemulsion method (Figure S6). 58 The initial absorption spectrum of aqueous dispersions of nanoparticles comprised two bands: a high tail peak corresponding to the mixture of absorption bands of ring-open GDTE and bisP [5]A and scattering of nanoparticles; a typical absorption of GD with the maximum absorption at 378 nm. A new absorption band at 527 nm appeared upon irradiation with UV light (310 nm), corresponding to that of dithienylethene in the ring-closed state (Figure 3b).…”

“…Controlling the flow of light at the micro-/nanoscale is a promising direction to fully exploit the potential function of optical waveguides . Most reported micro-/nanoscaled optical waveguides have focused on inorganic semiconductor waveguides, − organic micro-/nanocrystalline, − and polymeric micro-/nanofibrillar waveguides. − Compared with inorganic counterparts, organic micro-/nanomaterials are able to realize the tunable performance of optical waveguide by employing cooperative nanocrystal of multiple components or doped copolymer nanofiber. − However, cooperative nanocrystals are always prepared under harsh conditions, whereas covalent conjugated polymer nanofibers suffer from the tedious chemical modification.…”

“…Third and most importantly, the introduction of responsive monomers, including noninvasion photoresponsive unites, 32−36 into supramolecular polymers is easy to realize because of the dynamic nature of noncovalent interaction, 37 active optical waveguide properties. The supramolecular polymeric microfibers were drawn from concentrated solution of supramolecular polymers composed of bispillar [5]arene (bisP5A) and emissive diphenylanthracene derivative (GD) (Figure 1a). The resulting microfibers manifest excellent active optical waveguide property with very low optical propagation loss.…”