optogenetics using a Utah Optrode Array with enhanced light output and spatial selectivity.

Optogenetics allows the manipulation of neural circuitswith high spatial and temporal precision. However, combining this precision with control over a significant portion of the brain is technologically challenging (especially in larger animal models).Here, we have developed, optimised, and tested, the Utah Optrode Array (UOA), an electrically addressable array of optical needles and interstitial sites illuminated by 181LEDs and used to optogenetically stimulate the brain.

optogenetics using a Utah Optrode Array with enhanced light output and spatial selectivity.

Optogenetics allows manipulation of neural circuits with high spatial and temporal precision. However, combining this precision with control over a significant portion of the brain is technologically challenging (especially in larger animal models). Here, we have developed, optimised, and tested in vivo, the Utah Optrode Array (UOA), an electrically addressable array of optical needles and interstitial sites illuminated by 181 µLEDs and used to optogenetically stimulate the brain.

An optrode array for spatiotemporally-precise large-scale optogenetic stimulation of deep cortical layers in non-human primates.

Optogenetics has transformed studies of neural circuit function, but remains challenging to apply to non-human primates (NHPs). A major challenge is delivering intense, spatiotemporally-precise, patterned photostimulation across large volumes in deep tissue. Such stimulation is critical, for example, to modulate selectively deep-layer corticocortical feedback circuits.

An Optrode Array for Spatiotemporally Precise Large-Scale Optogenetic Stimulation of Deep Cortical Layers in Non-human Primates.

Optogenetics has transformed studies of neural circuit function, but remains challenging to apply in non-human primates (NHPs). A major challenge is delivering intense and spatially precise patterned photostimulation across large volumes in deep tissue. Here, we have developed and validated the Utah Optrode Array (UOA) to meet this critical need.

Overcoming the field-of-view to diameter trade-off in microendoscopy via computational optrode-array microscopy.

High-resolution microscopy of deep tissue with large field-of-view (FOV) is critical for elucidating organization of cellular structures in plant biology. Microscopy with an implanted probe offers an effective solution. However, there exists a fundamental trade-off between the FOV and probe diameter arising from aberrations inherent in conventional imaging optics (typically, FOV < 30% of diameter).

Maximizing transmittance in two-photon 3D printed materials for micro-optics in the visible.

We characterize three commercial resins suitable for three-dimensional two-photon printing of mm volume micro-optical components for visible light - IP-S, IP-n162, and IP-Visio - under different print modes and post-processing conditions. Due to the combination of cured resin absorption and bulk scattering, we find a maximum total printed thickness of 4 mm (or greater) for at least 50% transmittance of red light, up to 2 mm for green light, and large maximum thickness variation for blue light (0.1 to 1 mm).

Quantifying Exciton Heterogeneities in Mixed-Phase Organometal Halide Multiple Quantum Wells via Stark Spectroscopy Studies.

Solution-processable two-dimensional (2D) organic-inorganic hybrid perovskite (OIHP) quantum wells naturally self-assemble through weak van der Waals forces. In this study, we investigate the structural and optoelectronic properties of 2D-layered butylammonium (CHNH, BA) methylammonium (CHNH, MA) lead iodide, (BA)(MA)PbI quantum wells with varying from 1 to 4. Through conventional structural characterization, (BA)(MA)PbI thin films showcase high-quality phase () purity.

Approaches for deep-ultraviolet surface plasmon resonance sensors.

Aluminum (Al) is a preferred metal for designing deep-ultraviolet (DUV) surface plasmon resonance (SPR)-based sensors. The native oxide layer (alumina), which grows when the Al film is exposed to air, adds an extra layer to the multilayer stack and consequently affects the DUV-SPR sensing performance. To mitigate the performance loss in DUV-SPR-based sensing, new, to the best of our knowledge, approaches are considered here.

Circular photogalvanic spectroscopy of Rashba splitting in 2D hybrid organic-inorganic perovskite multiple quantum wells.

The two-dimensional (2D) Ruddlesden-Popper organic-inorganic halide perovskites such as (2D)-phenethylammonium lead iodide (2D-PEPI) have layered structure that resembles multiple quantum wells (MQW). The heavy atoms in 2D-PEPI contribute a large spin-orbit coupling that influences the electronic band structure. Upon breaking the inversion symmetry, a spin splitting ('Rashba splitting') occurs in the electronic bands.

Multisite microLED optrode array for neural interfacing.

We present an electrically addressable optrode array capable of delivering light to 181 sites in the brain, each providing sufficient light to optogenetically excite thousands of neurons , developed with the aim to allow behavioral studies in large mammals. The device is a glass microneedle array directly integrated with a custom fabricated microLED device, which delivers light to 100 needle tips and 81 interstitial surface sites, giving two-level optogenetic excitation of neurons . Light delivery and thermal properties are evaluated, with the device capable of peak irradiances per needle site.

Manifestation of Kinetic Inductance in Terahertz Plasmon Resonances in Thin-Film CdAs.

Three-dimensional (3D) semimetals have been predicted and demonstrated to have a wide variety of interesting properties associated with their linear energy dispersion. In analogy to two-dimensional (2D) Dirac semimetals, such as graphene, CdAs has shown ultrahigh mobility and large Fermi velocity and has been hypothesized to support plasmons at terahertz frequencies. In this work, we experimentally demonstrate synthesis of high-quality large-area CdAs thin films through thermal evaporation as well as the experimental realization of plasmonic structures consisting of periodic arrays of CdAs stripes.

Incident wavelength and polarization dependence of spectral shifts in β-GaO UV photoluminescence.

We report polarization dependent photoluminescence studies on unintentionally-, Mg-, and Ca-doped β-GaO bulk crystals grown by the Czochralski method. In particular, we observe a wavelength shift of the highest-energy UV emission which is dependent on the pump photon energy and polarization. For 240 nm (5.

THz characterization and demonstration of visible-transparent/terahertz-functional electromagnetic structures in ultra-conductive La-doped BaSnO Films.

We report on terahertz characterization of La-doped BaSnO (BSO) thin-films. BSO is a transparent complex oxide material, which has attracted substantial interest due to its large electrical conductivity and wide bandgap. The complex refractive index of these films is extracted in the 0.

Bloch Surface Wave-Coupled Emission at Ultra-Violet Wavelengths.

The interaction of fluorophores with nearby metallic structures is now an active area of research. Dielectric photonic structures offer some advantages over plasmonic structures, namely small energy losses and less quenching. We describe a dielectric one-dimensional photonic crystal (1DPC), which supports Bloch surface waves (BSWs) from 280 to 440 nm.

Utah optrode array customization using stereotactic brain atlases and 3-D CAD modeling for optogenetic neocortical interrogation in small rodents and nonhuman primates.

As the optogenetic field expands, the need for precise targeting of neocortical circuits only grows more crucial. This work demonstrates a technique for using Solidworks computer-aided design (CAD) and readily available stereotactic brain atlases to create a three-dimensional (3-D) model of the dorsal region of area visual cortex 4 (V4D) of the macaque monkey () visual cortex. The 3-D CAD model of the brain was used to customize an [Formula: see text] Utah optrode array (UOA) after it was determined that a high-density ([Formula: see text]) UOA caused extensive damage to marmoset () primary visual cortex as assessed by electrophysiological recording of spiking activity through a 1.

Maskless wafer-level microfabrication of optical penetrating neural arrays out of soda-lime glass: Utah Optrode Array.

Borrowing from the wafer-level fabrication techniques of the Utah Electrode Array, an optical array capable of delivering light for neural optogenetic studies is presented in this paper: the Utah Optrode Array. Utah Optrode Arrays are micromachined out of sheet soda-lime-silica glass using standard backend processes of the semiconductor and microelectronics packaging industries such as precision diamond grinding and wet etching. 9 × 9 arrays with 1100μ m × 100μ m optrodes and a 500μ m back-plane are repeatably reproduced on 2i n wafers 169 arrays at a time.

Thin-film optical notch filter spectacle coatings for the treatment of migraine and photophobia.

Previous evidence suggests optical treatments hold promise for treating migraine and photophobia. We designed an optical notch filter, centered at 480nm to reduce direct stimulation of intrinsically photosensitive retinal ganglion cells. We used thin-film technology to integrate the filter into spectacle lenses.

Changing the endpoints for determining effective obesity management.

Health authorities worldwide recommend weight loss as a primary endpoint for effective obesity management. Despite a growing public awareness of the importance of weight loss and the spending of billions of dollars by Americans in attempts to lose weight, obesity prevalence continues to rise. In this report we argue that effective obesity management in today's environment will require a shift in focus from weight loss as the primary endpoint, to improvements in the causal behaviors; diet and exercise/physical activity (PA).

Quantum size effect on dielectric function of ultrathin metal film: a first-principles study of Al(1 1 1).

Using first-principles calculations, we show manifestations of the quantum size effect in the dielectric function ε(2) of free-standing Al(1 1 1) ultrathin films of 1 monolayer to 20 monolayers, taking into account size dependent contributions from both interband and intraband electronic transitions. Overall the in-plane components (interband transition) of ε(2) increase with film thickness at all frequencies, converging towards a constant value. However, the out-of-plane components of ε(2) show a more complex behavior, and, only at frequencies less than 0.

Deep-tissue light delivery via optrode arrays.

We establish performance characteristics of needle-type waveguides in three-dimensional array architectures as light delivery interfaces into deep tissue for applications, such as optogenetic and infrared (IR) neural stimulation. A single optrode waveguide achieves as high as 90% transmission efficiency, even at tissue depths >1  mm. Throughout the visible and near-IR spectrum, the effective light attenuation through the waveguide is ∼3 orders of magnitude smaller than attenuation in tissue/water, as confirmed by both simulation and experimental results.

Large Fluorescence Enhancements of Fluorophore Ensembles with Multilayer Plasmonic Substrates: Comparison of Theory and Experimental Results.

Multilayer substrates consisting of a glass slide, silver mirror, silica layer, and silver nanoparticles were fabricated using magnetron sputtering. This new geometry of substrates with backplane mirror and dielectric photonic cavity produced large average fluorescence enhancements up to 190-fold. Fluorescence enhancements of five fluorescent probes were measured over the broad spectral range from 470 to 800 nm.

Optical antenna design for fluorescence enhancement in the ultraviolet.

Through rational design, we compare the performance of three plasmonic antenna structures for UV fluorescence enhancement. Among the antenna performance metrics considered are the local increase in excitation intensity and the increase in quantum efficiency, the product of which represents the net fluorescence enhancement. With realistic structures in aluminum, we predict that greater than 100× net enhancement can be obtained.

Exact field solution to guided wave propagation in lossy thin films.

Wave guidance is an important aspect of light trapping in thin film photovoltaics making it important to properly model the effects of loss on the field profiles. This paper derives the full-field solution for electromagnetic wave propagation in a symmetric dielectric slab with finite absorption. The functional form of the eigenvalue equation is identical to the lossless case except the propagation constants take on complex values.