THE EFFICIENCY OF THE USE OF INDIVIDUAL REMOVABLE DENTAL BITE SPLINTS FOR CORRECTION OF DENTAL DEFORMATIONS DEGREE IN PATIENTS WITH DENTURE DEFECTS

Objective: introduction of prevention methods and increase of the treatment efficacy of teeth deformations using individual dental bite splints. Materials and methods: The results of clinical examination of 67 patients of different age (20 to 59 years) with the existing dentition defects before and after use of individual removable dental bite splints are given in this article. The results of the work: the objective study showed a difference in data of the distances between certain points of the teeth surrounding the defect without dentition deformations and in their presence (distances АВ in the control and experimental groups was respectively 7.16 ± 0.19 mm and 4.32 ± 0.19 mm, АD -7.62 ± 0.19 mm and 4.16 ± 0.20 mm, ВС - 7.49 ± 0.19 mm and 4.07 ± 0.19 mm, СD – 6.96±0.19 mm and 3.67±0.19 mm). After the performance of the preparation of the patients with the dentition defects and deformations of the teeth with the use of individual dental bite splints to the prosthetic repair in several stages, it became possible to reduce significantly indexes of the distances in the presence of pathology and bring them closer to physiological data (АВ - 5.85 ± 0.21 mm, AD - 6.09 ± 0.18 mm, BC - 6.22 ± 0.19 mm, and СD- 5.73±0.19mm). Conclusions: The use of individual removable dental bite splints gave the possibility to improve significantly the prosthetic efficacy by normalizing the occlusal relations and chewing load onto the displaced teeth in the area of dentition defect

Waveguide integrated superconducting single-photon detectors with high internal quantum efficiency at telecom wavelengths

Superconducting nanowire single-photon detectors (SNSPDs) provide high efficiency for detecting individual photons while keeping dark counts and timing jitter minimal. Besides superior detection performance over a broad optical bandwidth, compatibility with an integrated optical platform is a crucial requirement for applications in emerging quantum photonic technologies. Here we present SNSPDs embedded in nanophotonic integrated circuits which achieve internal quantum efficiencies close to unity at 1550 nm wavelength. This allows for the SNSPDs to be operated at bias currents far below the critical current where unwanted dark count events reach milli-Hz levels while on-chip detection efficiencies above 70% are maintained. The measured dark count rates correspond to noise-equivalent powers in the 10-19 W/Hz-1/2 range and the timing jitter is as low as 35 ps. Our detectors are fully scalable and interface directly with waveguide-based optical platforms

On-chip coherent detection with quantum limited sensitivity

While single photon detectors provide superior intensity sensitivity, spectral resolution is usually lost after the detection event. Yet for applications in low signal infrared spectroscopy recovering information about the photon’s frequency contributions is essential. Here we use highly efficient waveguide integrated superconducting single-photon detectors for on-chip coherent detection. In a single nanophotonic device, we demonstrate both single-photon counting with up to 86% on-chip detection efficiency, as well as heterodyne coherent detection with spectral resolution f/∆f exceeding 1011. By mixing a local oscillator with the single photon signal field, we observe frequency modulation at the intermediate frequency with ultra-low local oscillator power in the femto-Watt range. By optimizing the nanowire geometry and the working parameters of the detection scheme, we reach quantum-limited sensitivity. Our approach enables to realize matrix integrated heterodyne nanophotonic devices in the C-band wavelength range, for classical and quantum optics applications where single-photon counting as well as high spectral resolution are required simultaneously

Quantum confined acceptors and donors in InSe nanosheets

We report on the radiative recombination of photo-excited carriers bound at native donors and acceptors in exfoliated nanoflakes of nominally undoped rhombohedral gamma-polytype InSe. The binding energies of these states are found to increase with the decrease in flake thickness, L. We model their dependence on L using a two-dimensional hydrogenic model for impurities and show that they are strongly sensitive to the position of the impurities within the nanolayer. (c) 2014 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution 3.0 Unported License

Room temperature electroluminescence from mechanically formed van der Waals III–VI homojunctions and heterojunctions

Room temperature electroluminescence from semiconductor junctions is demonstrated. The junctions are fabricated by the exfoliation and direct mechanical adhesion of InSe and GaSe van der Waals layered crystals. Homojunction diodes formed from layers of p- and n-type InSe exhibit electroluminescence at energies close to the bandgap energy of InSe (Eg= 1.26 eV). In contrast, heterojunction diodes formed by combining layers of p-type GaSe and n-type InSe emit photons at lower energies, which is attributed to the generation of spatially indirect excitons and a staggered valence band lineup for the holes at the GaSe/InSe interface. These results demonstrate the technological potential of mechanically formed heterojunctions and homojunctions of direct-bandgap layered GaSe and InSe compounds with an optical response over an extended wavelength range, from the near-infrared to the visible spectrum

Van der Waals SnSe2(1-x)S2x alloys: composition-dependent bowing coefficient and electron-phonon interaction

The design of advanced functional materials with customized properties often requires the use of an alloy. This approach has been used for decades, but only recently to create van der Waals (vdW) alloys for applications in electronics, optoelectronics, and thermoelectrics. A route to engineering their physical properties is by mixing isoelectronic elements, as done for the SnSe2(1−x)S2x alloy. Here, by experiment and first‐principles modeling, it is shown that the value of x can be adjusted over a wide range, indicating good miscibility of the SnS2 and SnSe2 compounds. The x‐dependence of the indirect bandgap energy from Eind = 1.20 eV for SnSe2 to Eind = 2.14 eV for SnS2, corresponds to a large bowing coefficient b ≈ 1 eV, arising from volume deformation and charge exchange effects due to the different sizes and orbital energies of the S‐ and Se‐atoms. This also causes composition‐dependent phonon energy modes, electron–phonon interaction, and temperature dependence of Eind. The alloys are exfoliable into thin layers with properties that depend on the composition, but only weakly on the layer thickness. This work shows that the electronic and vibrational properties of the SnSe2(1−x)S2x alloy and its thin layers provide a versatile platform for development and exploitation

High broad-band photoresponsivity of mechanically formed InSe-graphene van der Waals heterostructures

We exploit the broad-band transparency of graphene and the favorable band line up of graphene with van der Waals InSe crystals to create new functional heterostructures and high-performance photodetectors. The InSe-graphene heterostructure exhibits a high photoresponsivity, which exceeds that for other two-dimensional van der Waals crystals, and a spectral response that extends from the near-infrared to the visible spectrum. The highest photoresponsivity is achieved in device architectures where the InSe and graphene layers are vertically stacked, thus enabling effective extraction of photogenerated carriers from the InSe to the graphene electrodes