Search results for "Wavelength"
showing 10 items of 741 documents
Electron structure, ultra-dense hydrogen and low energy nuclear reactions
2019
In this paper, a simple Zitterbewegung electron model, proposed in a previous work, is presented from a different perspective based on the principle of mass- frequency equivalence. A geometric- electromagnetic interpretation of mass, relativistic mass, De Broglie wavelength, Proca, Klein- Gordon, Dirac and Aharonov- Bohm equations in agreement with the model is proposed. A non-relativistic, Zitterbewegung interpretation of the 3.7 keV deep hydrogen level found by J. Naudts is presented. According to this perspective, ultra-dense hydrogen can be conceived as a coherent chain of bosonic electrons with protons or deuterons located in the center of their Zitterbewegung orbits. This approach sug…
uality Evaluation of “Tardivo di Ciaculli” Mandarins in Post-Harvest Processing on an Industrial Scale Using a Portable Vis/NIR Device
2016
Abstract. Vis/NIR technology is widely used today to quickly and non-destructively evaluate fruit and vegetable qualities, and many applications have been found since the 1990s. However, no industrial-scale applications can further consolidate the use of non-destructive techniques in post-harvest processing. This study aims to test the possibility of applying vis/NIR technology in a modern citrus-processing plant to assess the damage that the fruits eventually suffer when they are processed on an industrial scale and the evolution of their key quality parameters in a period of 10 days after harvest. The spectral acquisitions were performed using a portable vis/NIR device, which operated in …
Polarization Insensitive Wavelength Conversion in a Low-Birefringence SiGe Waveguide
2016
We report the first demonstration of a single-pass dual-orthogonal-pump four-wave mixing-based wavelength conversion scheme in a silicon-based waveguide. The silicon germanium waveguide used was designed to exhibit strong TE/TM mode similarity across a broad wavelength range as well as a large nonlinear coefficient. A polarization-dependent loss of just 0.42 dB was measured, and the conversion of 40-Gb/s differential phase-shift keying signals was demonstrated with 1.5-dB power penalty at a bit error ratio of $10^{-9}$ .
Low-cost high-haze films based on ZnO nanorods for light scattering in thin c-Si solar cells
2015
Light scattering from ZnO nanorods (NR) is investigated, modeled, and applied to a solar cell. ZnO NR (120-1300 nm long, 280-60 nm large), grown by low-cost chemical bath deposition at 90 degrees C, exhibit diffused-to-total transmitted light as high as 70% and 30% in the 400 and 1000 nm wavelength range, respectively. Data and scattering simulation show that ZnO NR length plays a crucial role in light diffusion effect. A transparent ZnO NR film grown on glass and placed on top of a 1 mu m thick c-Si solar cell is shown to enhance the light-current conversion efficiency for wavelengths longer than 600 nm. (C) 2015 AIP Publishing LLC.
Towards an analytical framework for tailoring supercontinuum generation.
2016
A fully analytical toolbox for supercontinuum generation relying on scenarios without pulse splitting is presented. Furthermore, starting from the new insights provided by this formalism about the physical nature of direct and cascaded dispersive wave emission, a unified description of this radiation in both normal and anomalous dispersion regimes is derived. Previously unidentified physics of broadband spectra reported in earlier works is successfully explained on this basis. Finally, a foundry-compatible few-millimeters-long silicon waveguide allowing octave-spanning supercontinuum generation pumped at telecom wavelengths in the normal dispersion regime is designed, hence showcasing the p…
Optical retarder system with programmable spectral retardance.
2014
An optical system that works as a retarder waveplate with programmable spectral retardance is proposed. The system is based on a pixelated liquid crystal on silicon (LCoS) spatial light modulator (SLM). The input light beam is spectrally dispersed and different spectral components are projected onto different pixels of the LCoS-SLM. A different retardance is then addressed for each pixel, adapted to the incoming wavelength. Light reflected from the SLM is then recombined by the same setup. In this way a programmable polarization spectrum can be encoded. We illustrate the broadband characterization that is required for proper use of the system. Then several examples are shown, including spec…
Plasmonic Focusing Reduces Ensemble Linewidth of Silver-Coated Gold Nanorods
2008
Silver coating gold nanorods reduces the ensemble plasmon line width by changing the relation connecting particle shape and plasmon resonance wavelength. This change, we term "plasmonic focusing", leads to less variation of resonance wavelengths for the same particle size distribution. We also find smaller single particle linewidth comparing resonances at the same wavelength but show that this does not contribute to the ensemble linewidth narrowing.
Impact of dust and smoke mixing on column-integrated aerosol properties from observations during a severe wildfire episode over Valencia (Spain)
2017
The most destructive wildfire experienced in Spain since 2004 occurred close to Valencia in summer 2012. A total of 48.500ha were affected by two wildfires, which were mostly active during 29-30 June. The fresh smoke plume was detected at the Burjassot measurement station simultaneously to a severe dust episode. We propose an empirical method to evaluate the dust and smoke mixing and its impact on the microphysical and optical properties. For this, we combine direct-sun measurements with a Cimel CE-318 sun-photometer with an inversion methodology, and the Mie theory to derive the column-integrated size distribution, single scattering albedo (SSA) and asymmetry parameter (g). The mixing of d…
New sunphotometer for network operation.
1983
A handheld sunphotometer has been developed and is described. It operates for 9 wavelengths in the visible and near infrared. The sensitivity range is rather broad, so it can be used in turbid as well as clear atmospheres. The operation is simple, and a digital readout helps prevent operator biases. The instrument is sun powered and suitable for network operations. Determination of the atmospheric turbidity due to aerosol and the column content of O3, NO2, H2O is possible.
The alhambra photometric system
2010
Aparicio Villegas, Teresa et al.