Nanophotonic Materials Research Articles

Fluorescent/Circular Dichroic Dual-Mode Chiral Upconversion Nanocomposite for Diagnosis and Treatment of Rheumatoid Arthritis.

Chiral nanophotonic materials have emerged as ideal candidates for biosensing applications due to their exceptional sensitivity. However, the inability to directly visualize chiral signals limits their broader application, particularly in disease diagnosis and treatment. In this study, we introduce a chiral nanocomposite based on upconversion nanoparticles (UCNPs), denoted UCNPs@L-POM, that exhibits both upconversion luminescence (UCL) and circular dichroism (CD) signals. This dual-signal system enables ultrasensitive detection and in vivo imaging of ·OH. The detection limits for UCL and CD signals in aqueous solution are 6.258 and 0.912 μM, respectively. This dual-mode sensing approach is also effective at the cellular level. As a demonstration, UCNPs@L-POM enables in situ imaging diagnosis of rheumatoid arthritis (RA), characterized by elevated levels of ·OH expression. Additionally, through the oxidation reaction induced by ·OH, UCNPs@L-POM effectively alleviates paw inflammation and promotes the healing of RA. This work offers new prospects for biological applications of chiral nanocomposites.

Atomically Precise Fluorescent Gold Nanocluster as a Barrier-Permeable and Brain-Specific Imaging Probe.

Photonic nanomaterials play a crucial role in facilitating the necessary signal for optical brain imaging, presenting a promising avenue for early diagnosis of brain-related disorders. However, the blood-brain barrier (BBB) presents a significant challenge, blocking the entry of most molecules or materials from the bloodstream into the brain. To overcome this, photonic nanocrystals in the form of gold clusters (LAuC) with size less than 3 nm, have been developed, with Levodopa conjugated to LAuC (Dop@LAuC) for targeted brain imaging. Dop@LAuC crosses the BBB and emits in the near-infrared (NIR) wavelength, enabling real-time optical brain imaging. An in vitro BBB model using brain endothelial cells showed that 50 % of Dop@LAuC crossed the barrier within 3 hours, compared to only 10 % of LAuC, highlighting the enhanced ability of L-dopa-conjugated gold clusters to penetrate the BBB. In vivo optical imaging in healthy mice further confirmed the material's efficacy to cross BBB without compromising the barrier integrity.

Correlative Microscopy of Nanophotonic Materials

Correlative Microscopy of Nanophotonic Materials

Near‐Field Nanospectroscopy and Mode Mapping of Lead Telluride Hoppercubes

AbstractLead chalcogenides are compelling materials for nanophotonics and optoelectronics due to their high refractive indices, extreme thermo‐optic coefficients, and high transparency in the mid‐infrared (MIR). In this study, PbTe hoppercubes (HC, face‐open box cubes) are synthesized and explored for their MIR resonant characteristics. Single‐particle microspectroscopy uncovered deep‐subwavelength light localization, with a spectral response dominated by both fundamental and multiple high‐order Mie‐resonant modes. Nanoimaging mapping using scattering‐type scanning near‐field optical microscopy (s‐SNOM) reveals that the scattering at the center of the HC is reduced by more than five times compared to the edges. 2D‐Hyperspectral scans conducted using a low‐power broadband MIR source and nanometer spatial resolutions provided information on the local amplitude and phase‐resolved near‐fields, including amplitude and phase mapping of higher order modes with measured Q‐factors of close to 100. Employing s‐SNOM to characterize complex resonant nanophotonic structures holds implications for quantum sensing, IR photodetection, non‐linear generation, and ultra‐compact high‐Q metaphotonics.

First-principles simulations of high-order harmonics generation in thin films of wide bandgap materials [Invited

High-order harmonics generation (HHG) is the only process that enables tabletop-sized sources of extreme ultraviolet (XUV) light. The HHG process typically involves light interactions with gases or plasma––material phases that hinder wider adoption of such sources. This motivates the research in HHG from nanostructured solids. Here, we employ the time-dependent density function theory (TDDFT) to investigate material platforms for HHG at the nanoscale using first-principles supercomputer simulations. We reveal that wide bandgap semiconductors, aluminum nitride (AlN) and silicon nitride (Si3N4), are highly promising for XUV light generation when compared to silicon, one of the most common nonlinear nanophotonic materials. In our calculations, we assume excitation with a 100 fs pulse duration, 1×1013W/cm2 peak power, and 800 nm central wavelength. We demonstrate that in AlN material the interplay between the crystal symmetry and the incident light direction and polarization can enable the generation of both even and odd harmonics. Our results should advance the development of high-harmonics generation of XUV light from nanostructured solids.

Adaptive multi-spectral mimicking with 2D-material nanoresonator networks

Active nanophotonic materials that can emulate and adapt between many different spectral profiles—with high fidelity and over a broad bandwidth—could have a far-reaching impact, but are challenging to design due to a high-dimensional and complex design space. Here, we show that a metamaterial network of coupled 2D-material nanoresonators in graphene can adaptively match multiple complex absorption spectra via a set of input voltages. To design such networks, we develop a semi-analytical auto-differentiable dipole-coupled model that allows scalable optimization of high-dimensional networks with many elements and voltage signals. As a demonstration of multi-spectral capability, we design a single network capable of mimicking four spectral targets resembling select gases (nitric oxide, nitrogen dioxide, methane, nitrous oxide) with very high fidelity ( >90% ). Our results could impact the design of highly reconfigurable optical materials and platforms for applications in sensing, communication and display technology, and signature and thermal management.

Upconverted Chiral Emission in Hybrid Photonic Nanomaterials: Toward Amplified Circularly Polarized Luminescence with Tunable Chirality

Upconverted Chiral Emission in Hybrid Photonic Nanomaterials: Toward Amplified Circularly Polarized Luminescence with Tunable Chirality

Research on antennas based on nanophotonic materials

In this study, the performance of bilayer graphene and its dual-frequency reconfigurable antenna structure on SiO2/Si substrates was explored. The research underscores that when compared to traditional radio frequency and microwave antennas, the performance of nano-optical antennas is strongly contingent on their size and shape. It is also intimately related to their intrinsic material properties, highlighting the unique physical attributes and scaling behavior of nano-photonic antennas. A salient feature of bilayer graphene is its ability to dynamically adjust its conductivity by applying an external voltage between the two layers, offering new prospects for its application in micro-nano electronics and photonics. Through a comparative analysis of radiation decay rates and quantum efficiency, it was determined that metallic materials exhibit much higher non-radiative losses than nano-optical materials. This research provides a foundational theoretical framework for future experiments and paves the way for creating secure information networks. However, the study acknowledges the potential challenges in the real-world application and production of nano-photonic antennas, suggesting further exploration in optimizing their structure to enhance efficiency.

Correlative microscopy and spectroscopy of nanophotonic materials

Correlative microscopy and spectroscopy of nanophotonic materials

Quantum Semiconductors Based on Carbon Materials for Nanophotonics and Photonics Applications by Electron Shuttle and Near Field Phenomena

This review intended to resume key Research reports and publications that open many themes and topics related to Carbon-based semiconductors and Quantum emitters. The Design and synthesis of highly pure materials such as Graphene, Carbon Nanotubes, fullerenes, and other Carbon-based allotropes were shown. They presented their most important and promising properties concerning new studies and developments in photonics. Carbon-based Quantum dots, semiconductors, and higher sized Nanoplatforms allowed us to discuss fundamental studies and perspectives within varied applications. In this context, relevant developments from literature related to electron transfer within various targeted processes, where energy and light transfers occurred through different optical active materials and platforms, were highlighted and discussed. Therefore, many approaches that tuned the desired Optical active properties were shown. Thus, Hybrid materials from single Quantum and Nanoplatforms towards modified substrates were incorporated within varied media such as colloidal dispersions, solid devices, and waveguides. Moreover, Heterojunctions and applications such as energy harvesters and emitter devices were also presented. This manner highlighted varied topics of Photonics' leading current status, perspectives, and implications in Nanophotonics, Quantum photonics, and Optical lenses. Further views and commentaries about Green Photonics were presented as well.

Direct ultrafast carrier imaging in a perovskite microlaser with optical coherence microscopy

Nanophotonics is an actively developing field of optics that finds application in various areas, from biosensing to quantum computing. The study of ultrafast modulation of the refractive index Δn is an important task in nanophotonics, since it reveals the features of light–matter interaction inside devices. With the development of active photonic devices such as emitters and modulators, there is a growing need for Δn imaging techniques with both high spatial and high temporal resolutions. Here, we report on an all-optical ultrafast Δn imaging method based on phase-sensitive optical coherence microscopy with a resolution of 1 ps in time and 0.5 µm in space and a sensitivity to Δn down to 10−3RIU. The advantages of the method are demonstrated on emerging nanophotonic devices—perovskite microlasers, in which the ultrafast spatiotemporal dynamics of the refractive index during lasing is quantitatively visualized, illustrating the features of relaxation and diffusion of carriers in perovskites. The developed method allows us to estimate the ultrafast carrier diffusion and relaxation constants simultaneously and to show that the CsPbBr3 perovskite carrier diffusion coefficient is low compared to other semiconductors even during lasing at high carrier densities, which leads to high localization of the generated carrier cloud, and, consequently, to high fluorescence and lasing efficiency. The resulting technique is a versatile method for studying ultrafast carrier transport via Δn imaging, paving an avenue for the applications of optical coherence tomography and microscopy in the research of nanophotonic devices and materials.

Plasmon enhancement of third-order nonlinear optical absorption of gold nanoparticles dispersed in planar oriented nematic liquid crystals

We report structural and nonlinear optical properties of 20 nm gold (Au) nanoparticles (NPs) that are dispersed in planar degenerate (non-oriented) and planar oriented nematic liquid crystals (LCs) (4′-Pentyl-4-biphenylcarbonitrile-5CB). Taking advantage of elastic forces in the planar oriented nematic LC, we aligned AuNPs parallel to the 5CB director axis. In the case of planar degenerate, 5CB is not aligned and has no preferred orientation, forcing the AuNPs to disperse randomly. Results show that the linear optical absorption coefficient for the planar oriented 5CB/AuNPs mixture is larger than the corresponding planar degenerate sample. The nonlinear absorption coefficients are greatly enhanced in planar oriented samples at relatively high concentrations which can be attributed to plasmon coupling between the aligned AuNPs. This study demonstrates the utility of LCs for developing the assembly of NPs with enhanced optical properties which may offer important insight and technological advancement for novel applications, including photonic nanomaterials and optoelectronic devices.

Bulk ReSe2: Record High Refractive Index and Biaxially Anisotropic Material for All-Dielectric Nanophotonics

We show that bulk rhenium diselenide, ReSe2, is characterized by a record high value of the refractive index exceeding 5 in the near-infrared frequency range. We use back focal plane reflection spectroscopy to extract the components of the ReSe2 permittivity tensor and reveal its extreme biaxial anisotropy. We also demonstrate the good agreement between the experimental data and the predictions of the density functional theory. The combination of the large refractive index and giant optical anisotropy makes ReSe2 a promising material for all-dielectric nanophotonics in the near-infrared frequency range.

PCA-Enhanced Autoencoders for Nonlinear Dimensionality Reduction in Low Data Regimes

Many scientific domains, such as nanophotonic design, gene expression, and materials design, are limited by high costs of acquiring data. This data is often intrinsically low-dimensional, nonlinear, and benefits from dimensionality reduction. Autoencoders (AE) provide nonlinear dimensionality reduction but are typically ineffective for low data regimes. Principal Component Analysis (PCA) is data-efficient but limited to linear dimensionality reduction. We propose a technique that harnesses the benefits of both methods by using PCA to initialize an AE. The proposed approach outperforms both PCA and standard AEs in low-data regimes and is comparable to the best of either of the two in other scenarios.

Comparison of Harmonic Generation from Crystalline and Amorphous Gallium Phosphide Nanofilms

AbstractGallium phosphide (GaP) is a promising material for nanophotonics, given its large refractive index and a transparency over most of the visible spectrum. However, since easy phase‐matching is not possible with bulk GaP, a comprehensive study of its nonlinear optical properties for harmonic generation, especially when grown as thin films, is still missing. Here, second harmonic generation is studied from epitaxially grown GaP thin films, demonstrating that the absolute conversion efficiencies are comparable to a bulk wafer over the pump wavelength range from 1060 to 1370 nm. Furthermore, the results are compared to nonlinear simulations, and the second order nonlinear susceptibility is extracted, showing a similar dispersion and magnitude to that of the bulk material. Furthermore, the third order nonlinear susceptibility of amorphous GaP thin films is extracted from third harmonic generation to be more than one order of magnitude larger than that of the crystalline material, and generation of up to the fifth harmonic is reported. The results show the potential of crystalline and amorphous thin films for nonlinear optics with nanoantennas and metasurfaces, particularly in the visible to near infrared part of the spectrum.

MP05-15 PHOTONIC LITHOTRIPSY: EFFECT OF GOLD AND CARBON BASED NANOMATERIALS ON STONE COMMINUTION

You have accessJournal of UrologyCME1 Apr 2023MP05-15 PHOTONIC LITHOTRIPSY: EFFECT OF GOLD AND CARBON BASED NANOMATERIALS ON STONE COMMINUTION Ian Houlihan, Benjamin Kang, Smita De, and Vijay Krishna Ian HoulihanIan Houlihan More articles by this author , Benjamin KangBenjamin Kang More articles by this author , Smita DeSmita De More articles by this author , and Vijay KrishnaVijay Krishna More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003216.15AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Kidney stones affect ∼10% of individuals in the USA. The most common surgical stone treatments include laser lithotripsy by ureteroscopy and extracorporeal shock wave lithotripsy. Photonic lithotripsy (PL) is a novel technology for minimally-invasive, non-contact kidney stone treatment. PL utilizes photonic nanomaterials that convert low-intensity (<5 W), near-infrared laser energy to photothermal and/or photoacoustic energy for kidney stone fragmentation. Herein we investigate the effect of different photonic nanomaterials on PL. METHODS: Human kidney stones with a size range of 2–4 mm and a composition of >70% calcium oxalate (CaOx) were obtained from the Cleveland Clinic Pathology Lab. Five different photonic nanomaterials were evaluated: gold nanoshells (AuNS), gold nanorods (AuNR), multi-walled carbon nanotubes (MWNT), graphene oxide (GO), and polyhydroxy fullerenes (PHF). Each nanomaterial at each laser wavelength and power setting was tested with n=10 stones. Stones were treated with photonic nanomaterials and exposed to a NIR laser (785 nm or 1320 nm) at a distance of 10 mm for three, 3-minute intervals. Multiple intervals were used to observe changes and re-expose stones to the nanomaterial solution. The treatments were considered successful if two or more fragments were produced. RESULTS: Stones predominantly CaOx based were successively fragmented using the different nanomaterials (Figure 1) when irradiated with the 1320 nm and 785 nm NIR lasers. The 1320 nm laser successfully broke >50% of stones across all nanomaterials at 4 W and >30% of stones at 3 W. The 785 nm laser successfully broke >80% of stones across all nanomaterials at 2 W. No stones were fragmented at 1 W as not enough energy was generated for failure to occur. The stones analyzed pre and post PL by FTIR and µCT showed evidence of crack formation and thermal degradation. CONCLUSIONS: Photonic nanomaterials can fragment stones using laser wavelengths that are minimally absorbed by kidney tissue, at low energy and in non-contact mode at a distance of 10 mm. Successful stone comminution with different nanomaterials is dependent upon laser wavelength and laser power. All tested nanomaterials have the ability to fragment kidney stones in an in vitro setting. Source of Funding: LRI Accelerator Grant, Cleveland Clinic Caregiver Catalyst Award, U2Csupport 1U2CDK129440 © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e49 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Ian Houlihan More articles by this author Benjamin Kang More articles by this author Smita De More articles by this author Vijay Krishna More articles by this author Expand All Advertisement PDF downloadLoading ...

Mesoporous Natural Fiber Welded Cellulose Containing Silver Nanoparticles as a Recyclable Heterogeneous Catalyst

AbstractSilver nanoparticles (AgNPs) are presented within mesoporous natural fiber welded (NFW) cellulose and demonstrated as robust catalysts to reduce 4‐nitrophenol using sodium borohydride. Growing AgNPs this way enables their retention within a nonderivatized, mesoporous, all‐cellulose NFW composite. At an AgNP loading of 1.0 wt%, no leaching is observed during rinsing with polar and nonpolar solvents or any of 12 catalyst cycles and the cloth is easily retrievable and reusable. Comparatively, a 1.0 wt% AgNP loading on non‐NFW cotton thread loses ≈95% of the starting Ag under similar conditions. Only at higher loadings is a very slow leaching observed in the NFW composite (&lt;10% Ag loss). With a turnover frequency of 0.9 h–1 (as compared to 2.2 h–1 for the non‐NFW cotton thread), the catalytic activity suffers only minor impedance from the NFW structure while affording significant promise in future applications for leach‐resistant nonderivatized cotton (e.g., TiO2 or photonic nanomaterials). Finally, it is shown that combustion of AgNPs‐NFW composites creates Ag residues distinct from materials produced via combustion of AgNPs on non‐NFW cotton. While the residues produced comprise Ag and residual carbon, this method is viable for producing metal “sponges” from monometallic and bimetallic NPs on mesoporous cellulose.

Gold Nanoparticle–Polyelectrolyte Complexes with Tunable Structure Probed by Synchrotron Small-Angle X-ray Scattering: Implications for the Production of Colloidal Crystals-Based Nanophotonic Materials

Close-packed colloidal crystals of gold nanoparticles (AuNPs) are of great interest in the field of nanophotonics due to their lattice-pattern-dependent optical properties. One challenge resides in producing such crystalline assemblies by a scalable approach involving polydisperse AuNPs obtained by standard synthesis routes and structuring natural molecules in water at room temperature. Electrostatic complexation between functionalized AuNPs and oppositely charged polyelectrolytes (PELs) is a very simple way to create AuNP self-assemblies of different morphologies and compactness. Our work investigates, using synchrotron small-angle X-ray scattering, their structure as a function of concentration, PEL persistence length and ionic strength. By decreasing the radius, R, of the positively charged gold nanoparticles to a few nm (R ≤ 3 nm) and increasing the polyelectrolyte persistence length, LT, substituting flexible sodium polystyrenesulfonate for natural semiflexible hyaluronan, we tuned the characteristic ratio LT/R up to values of ≥1.85. Such ratios allow the successful formation of a new AuNPs arrangement with a high degree of short-range order at low ionic strength and of crystalline order when interactions are screened by addition of salt. This approach involving commercially available natural water-soluble semiflexible PELs, opens a low-cost and promising way for the one-step production of gold colloidal crystals, which can be of ubiquitous utility in nanophotonics.

First-principles calculations to investigate electronic band structure, optical and mechanical properties of new CaFCl monolayer

Two-dimensional materials present new opportunities to venture into largely unexplored areas of material property space. They are appropriate for several electronic powers, photonics, and sunlight device applications. In this framework, leveraging density functional theory and even beyond, we investigate the structural, vibrational, electronic, optical, and elastic properties of novel CaFCl thin film. We have found that the CaFCl sheet is dynamically stable because its spectrum contains no imaginary frequencies. The direct band gap energy value of our GW findings is around 9.10 eV, which really is higher than the band gaps of ScOI and InOF oxyhalides thin films. We have found that the external electric fields immediately affect the structure of the layer. The band gap of the CaFCl structure is reduced rapidly by increasing the strength of the electric field. Additionally, our Bethe–Salpeter theory calculations demonstrate that when the excitation light rate is greater than the resonance frequency (8.00 eV), the substance becomes translucent. We have also used the method of homogeneous deformation, which is coupled with density functional theory and random phase approximation total-energy computations to produce a comprehensive scheme for studying the second-and third-order elastic constants for the CaFCl layer. A polynomial fit to the estimated energy-strain connection yielded these constants. Our results reveal that this 2D monolayer is a promising material for nanophotonics and optoelectronics.

Scalable Superabsorbers and Color Filters Based on Earth-Abundant Materials.

Optical materials based on unconventional plasmonic metals (e.g., magnesium) have lately driven rising research interest for the quest of possibilities in nanophotonic applications. Several favorable attributes of Mg, such as earth abundancy, lightweight, biocompatibility/biodegradability, and its active reactions with water or hydrogen, have underpinned its emergence as an alternative nanophotonic material. Here, we experimentally demonstrate a thin film-based optical device composed exclusively of earth-abundant and complementary metal-oxide semiconductor (CMOS)-compatible materials (i.e., Mg, a-Si, and SiO2). The devices can exhibit a spectrally selective and tunable near-unity resonant absorption with an ultrathin a-Si absorbing layer due to the strong interference effect in this high-index and lossy film. Alternatively, they can generate diverse reflective colors by appropriate tuning of the a-Si and SiO2 layer thicknesses, including all the primary colors for RGB (red, green, blue) and CMY (cyan, magenta, yellow) color spaces. In addition, the reflective hues of the devices can be notably altered in a zero power-consumption fashion by immersing them in water due to the resulted dissolution of the Mg back-reflection layer. These compelling features in combination with the lithography-free and scalable fabrication steps may promise their adoption in various photonic applications including solar energy harvesting, optical information security, optical modulation, and filtering as well as structure reuse and recycling.