An adaptive-focus lens is a device that capable of tuning its focal length by means an external stimulus. Numerous techniques for the demonstration such devices have been reported thus far. Moving beyond traditional solutions, several new approaches proposed in recent years based on use liquid crystals, which can great impact emerging applications. This work focuses advances crystal lenses with diameters larger than 1 mm. Recent demonstrations and their performance characteristics are...

In this work, a dielectric metasurface consisting of hollow nanocuboids, with ultrahigh quality factor, is theoretically proposed and demonstrated. The variation the hole size cuboid allows for tuning resonant anapole mode in nanoparticles. designed to operate two complementary modes, namely electromagnetically induced transparency narrowband selective reflection. Thanks non-radiative nature resonances, minimal absorption losses materials, near-field coupling among nanoparticles, very high...

In this work, a novel all-dielectric metasurface made of arrayed circular slots etched in silicon layer is proposed and theoretically investigated. The structure designed to support both Mie-type multipolar resonances symmetry-protected bound states the continuum (BIC). Specifically, consists interrupted slots, following paradigm complementary split-ring resonators. This configuration allows silicon-on-glass free-standing metasurfaces arc length split-rings provides an extra tuning...

We theoretically and experimentally investigate a metasurface supporting silicon-slot quasi-bound state in the continuum (qBIC) mode resonating near-infrared spectrum. The is composed of circular slots etched silicon layer on sapphire substrate. symmetry unit cell reduced order to provide access symmetry-protected mode, whose properties are investigated by finite-element full-wave eigenfrequency analysis. measured transmittance spectra verify excitation qBIC with experimental quality factors...

This work proposes the use of refractive index sensitivity non-radiating anapole modes high-refractive-index nanoparticles arranged in planar metasurfaces as a novel sensing principle. The spectral position excited hollow silicon nanocuboids is first investigated function nanocuboid geometry. Then, nanostructured periodic arrays on glass substrate are designed. metasurface parameters properly selected such that resonance with ultrahigh Q-factor, above one million, at target infrared...

A novel liquid crystal microlens array with tunable multifocal capability, high optical power and fill-factor is proposed experimentally demonstrated. specific hole pattern design produces a only one voltage control. Three operations modes are possible, "Off", "Tunable Multifocal" "Unifocal". The patterned in both substrates. Then, the substrates arranged symmetrical configuration. result comparison typical structures. Besides, it hexagonal that fill factor, specially indicated for some...

Solar simulators are a fundamental instrument to characterize solar cells parameters, as they can reproduce the operating conditions under which going work. However, these systems frequently big, heavy, and expensive, small simulator could be good contribution test prototyping devices manufactured in research labs, especially if it manage irradiation at any wavelength interval custom way. We have designed, developed, calibrated made entirely with LEDs, no optics inside, electronically...

In this work, a silicon metasurface designed to support electromagnetically induced transparency (EIT) based on quasi-bound states in the continuum (qBIC) is proposed and theoretically demonstrated near-infrared spectrum. The consists of periodic array square slot rings etched layer. interruption by bridge breaks symmetry structure producing qBIC stemming from symmetry-protected states, as rigorously group theory analysis. One found behave resonance-trapped mode perturbed metasurface, which...

A visible light communication (VLC) system using an organic bulk heterojunction photodetector (OPD) is presented. The has been successfully proven indoors with audio signal. emitter consists of three commercial high-power white LEDs connected in parallel. receiver based on having as active layer a blend poly(3-hexylthiophene) (P3HT) and phenyl C61-butyric acid methyl ester (PCBM). OPD opto-electrically characterized, showing responsivity 0.18 A/W modulation response 790 kHz at −6 V.

Abstract This work presents the application of an experimental nematic liquid crystal (LC) mixture (1929) in a large aperture lens. The LC material is composed terphenyl and biphenyl derivatives compounds with isothiocyanate terminal group fluorinated lateral substituents. substitution strongly polar aromatic rigid core provides $$\pi$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>π</mml:mi> </mml:math> -electron coupling, providing high birefringence ( $$\Delta n =...

Abstract A single‐layer, all‐dielectric metasurface exhibiting a strong toroidal resonance in the low‐atmospheric loss radio window of subterahertz W‐band is theoretically proposed and experimentally demonstrated. The fabricated on high‐resistivity floating‐zone silicon wafer by means single‐process, wet anisotropic etching technique. properties mode both constituent dielectric elements are rigorously investigated multipole decomposition technique full‐wave simulations. experimental...

Abstract An all‐dielectric metasurface exhibiting a strong toroidal resonance is theoretically designed and experimentally demonstrated as an angular‐dependent resonant polarization beam‐splitter in the microwave K‐band. The fabricated by embedding square periodic array of high‐permittivity ceramic cuboid resonators 3D‐printed substrate polylactic acid. It that properly selecting resonator geometry tuning angle incidence through mechanical rotation, can switch between beam splitting bandpass...

In this work, a technique to generate aspherical liquid crystal lenses with positive and negative optical power is experimentally demonstrated. The main enabling element micro-metric electrode variable spatial size. This produces decreasing resistance towards the lens centre that generates desired voltage/phase profiles. Then, voltage homogeneously distributed across active area of by concentric electrodes. As it demonstrated, phase shift can be controlled voltages from 0 4.5 VRMS. result,...

Cost-effective and lightweight solar cells are currently demanded in strategic fields such as space applications or integrated-wearable devices. A reduction of the active layer thickness, producing thin-film devices, has been a traditional solution to accomplish both requirements. However, this also reduces efficiency device. For reason, alternative strategies being proposed. In work, light trapping effects an array semiconductor nanoparticles located on top surface GaAs cell investigated...

In this work, a compact design of an electrically tunable notch filter, based on liquid crystal (LC) technology, has been designed, manufactured, and characterized. The proposal achieved through particular configuration schemes with low cost inverted-microstrip structures conventional spurlines due to its ease integration. Central frequency tunability induced by applying ac voltages, thus involving power consumption. For these devices, filter responses have approached specifically at...

In recent years, many experimental and theoretical research groups worldwide have actively worked on demonstrating the use of liquid crystals (LCs) as adaptive lenses for image generation, waveform shaping, non-mechanical focusing applications. particular, important achievements concerned development alternative solutions 3D vision. This work focuses design evaluation electro-optic response a LC-based 2D/3D autostereoscopic display prototype. A strategy achieving vision has been implemented...

A novel temperature sensor based on nematic liquid crystal permittivity as a sensing magnitude, is presented. This consists of specific micrometric structure that gives considerable advantages from other previous related (LC) sensors. The analytical study reveals change with introduced in hyperbolic cosine function, increasing the sensitivity term considerably. experimental data has been obtained for ranges −6 °C to 100 °C. Despite this, following LC datasheet, theoretical −40 109 could be...

Visible light communication systems can be used in a wide variety of applications, from driving to home automation. The use wearables increase the potential applications indoor send and receive specific customized information. We have designed developed fully organic flexible Light Communication system using OLED, P3HT:PCBM-based photodiode (OPD) PCBs for emitter receiver conditioning circuits. fabricated characterized I-V curve, modulation response impedance OPD. As we commercial luminaire...