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A time-domain polarization spectrometer with ultra-broad band (0.3∼30THz) and high angular resolution (up to several minutes) has been set up based on terahertz air photonics. Its construction, performances and applications are introduced.
The theoretical analysis of a recent experiment on the modified radiation dynamics of a magnetic dipole emitter embedded in a three-dimensional Photonic Band Gap material is presented. This analysis allows the first-time demonstration of non-Markovian dynamics.
We present theoretical discoveries of frequency-isolated Weyl points and line nodes, 3D linear point- and line-degeneracies, in gyroid photonic crystals. The associated surface states exhibit topological-protection and flat bands realizable from microwave to optical frequencies.
Probing of delicate systems demands high sensitivity from limited probe energy. Quantum optical techniques to beat the standard quantum limit (SQL) offer a practical advantage for these measurements. Here we report the first entanglement-enhanced measurement of a delicate material system [1]. We non-destructively probe an atomic spin ensemble by near-resonant Faraday rotation, a measurement that is...
We report the first observation of stable single photon sources in an electronic and photonic device-friendly material, silicon carbide (SiC). SiC is a viable material for implementing quantum communication, computation and photonic technologies.
A 4.4 % RF-sputtered Cu2ZnSnSe4 thin film solar cell was studied by transmittance electron microscopy (TEM) and photoluminescence (PL). The result reveals non-uniform elemental distribution and large potential fluctuation mainly induced by CuZn defect.
The insulator-metal transition (IMT) property of vanadium dioxide provides a large, abrupt change in refractive index, making it a good candidate active material for optical modulators. We show, in this paper, that plasmonic modulators can leverage the high modulation contrast of vanadium dioxide, while at the same time solve the problems of high insertion loss and high phase-transition electric-field...
In view of new generation integrated photonic devices, we present our computational as well as fabrication results on the investigation of photonic chiral lattices with diverse transversely quasicrystallographic symmetries. As the photonic band gap becomes becomes more symmetric as well as the directional tunability is enhanced in photonic quasi crystals (PQC), they would give an additional degree...
Though some encounters with potentially illicit radiological or nuclear material involve a stationary or dwell survey, many of the conceivable encounters are dynamic in nature. In the general unshielded or homogeneously shielded dynamic encounter, the mean detectable source signature strength will follow a well behaved curve with time: increasing on approach, peaking at the point-of-closest-approach,...
New developments in detector technology allow the acquisition of micrometer-resolution x-ray transmission images of specimens as large as a few millimeters at unprecedented frame rates. The high x-ray flux density generated by the Advanced Photon Source (APS) allows for detector exposure times ranging from hundreds of milliseconds to 150 picoseconds. The synchronization of the camera with the rotation...
The a-Si:H deposition process is systematically investigated in intrawafer and wafer-to-wafer experiments. Photonic ring resonators were studied within-chip and chip-to-chip, showing ±1.2nm resonance peak variations and deviations of 0.25% (intrachip) and 0.9%(interchip) for group index and FSR.
The x-pinch has proven to be a valuable continuum and line radiation source in high energy density (HED) plasma diagnostics such as x-ray absorption spectroscopy1 and monochromatic backlight imaging2. Landen et al.3 have shown laser-produced plasma x-ray sources can be successfully used to probe the high densities (ne > 1021 cm−3) encountered in many HED plasmas of interest by way of x-ray Thomson...
In the broad field of photonics artificially structured periodic materials (so-called photonic crystals) play a key role due to their extraordinary electromagnetic properties. One of which is the existence of (multiple) bandgaps. Resulting, these materials allow for electromagnetic wave propagation in distinct frequency ranges. Furthermore, systematically introduced defects in periodicity enable to...
The technology of increasing Internal Vcc without using memory tester is used to enhance the photon emission and the failure range is defined in detail by nano probing. With these methods, we found out that the leakage current was caused by dislocations of STI arranged in a row.
Structures similar to those found on butterfly wings were produced holographically on thin layers of dichromated pullulan. Light propagation and scattering is studied in these nanometre periodic structures, and in the wings of Lepidoptera (moths and butterflies). We have found that the width of photonic band-gaps in each case is influenced by light localization (either weak or strong), due to certain...
Optimizing the performance of optical fibres or photonic devices often boils down to the identification of a proper dielectric material, or to a systematic modification of an existing basic material. With modern ab initio simulation methods based on density functional theory, it is possible to model dielectric properties from the bottom-up. Starting with the atomic and electronic structure of the...
We investigate the use of pulsed bremsstrahlung as a standoff active interrogation tool for the production of neutron and gamma signatures in fissionable materials.1 Photons are generated by an electron beam striking a Ta converter on the 16 MV Hermes III facility at Sandia National Laboratories, and propagate to a target location 19 m from the electron beam diode, at which various materials are placed...
The luminescent materials that have been used for luminescent down-shifting (LDS) range from organic molecules and organometallic complexes to quantum dots (QDs), each of them with certain strengths and weaknesses. In this work, we introduce five figures of merit to quantitatively evaluate how the properties of these materials compare with the desirable properties of an optimum LDS layer, focusing...
Cerium-doped yttrium aluminum garnet (YAG:Ce) is used as the down-conversion materials to improve light absorption of solar cells. Experimental results show that coating YAG:Ce phosphors on surfaces of single crystalline silicon solar cells can enhance internal quantum efficiency in short wavelength range. This indicates that more photons can be generated when shorter wavelength photons hit cell's...
This paper studies the feasibility of using GaN/InGaN quantum dot as the Intermediate Band Solar Cell. Different dot sizes and layers are compared and the result shows significant differences due to different quantum confinement strength. The band structure and transition rate in the quantum dot are calculated. The efficiency of the strucutre can reach 31% in this structure. With these information,...
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