Article history: Received 12 June 2015 Received in revised form 14 July 2016 Accepted 9 September 2016 Available online 9 November 2016

To establish an underwater communication system for a swarm of submersibles, we developed an optical communication transceiver, small in size, combining the IrDA physical layer with 3 Watt high power light emitting diodes, emitting light in the green and blue part of the visible spectrum. This paper presents experimental results in air and under water. Furthermore, we show how this digital comm...

The optical absorption of pure liquid water in the 300-700-nm region has been measured by use of a long (1.5-m) path-length cell. The absorption spectrum coincides well with the edge of previous data in the 200-320-nm region and provides reliable data in the 320-420-nm region that has until now been a region of considerable unreliability. The data obtained for the 420-700-nm region agree quite ...

Scattering to extinction cross-section ratios, qse, were measured using the NIST Large Agglomerate Optics Facility for soot produced from ethene and acetylene laminar diffusion flames. Measurements were performed using light sources at 543.5 nm, 632.8 nm, and 856 nm. The average scattering to extinction cross-section ratios for these wavelengths are equal to 0.245, 0.195, and 0.195 for ethene a...

Nano-crystalline particles of CeO2 have been synthesized by a low temperature chemical precipitation method. The precursor materials used in this research were Ce(NO3)3.6H2O, NaOH and diethylene glycol as surfactant. X-ray powder diffraction results showed that face centered cubic CeO2 nanoparticles with crystalline size in nanometer scale were formed. Scanning electron microscopy measurement s...

Pedestrian detection from images of the visible spectrum is a high relevant area of research given its potential impact in the design of pedestrian protection systems. There are many proposals in the literature but they lack a comparative viewpoint. According to this, in this paper we first propose a common framework where we fit the different approaches, and second we use this framework to pro...

We have built and characterized batch-processed polarization beam splitters (PBS), important optical components to separate the orthogonal TE and TM components of light. The devices were fabricated from thin-film, low-stress silicon nitride membranes and showed excellent performance. By stacking membranes, and a triple-layer PBS produced extinction ratios of 21 and 16dB for reflected and transm...

Cadmium Oxide (CdO) nanoparticles were prepared by precipitation method using Cadmium acetate and ammonia solution. Presence of chemical species, were verified by Fourier Transform Infra Red (FTIR) Spectrum. From X-Ray Diffraction (XRD) spectrum the particle size, d-spacing value and structure of the nanoparticle were analysed. Size of the nanoparticles and the elemental composition were detect...

Cadmium Oxide (CdO) nanoparticles were prepared by precipitation method using Cadmium acetate and ammonia solution. Presence of chemical species, were verified by Fourier Transform Infra Red (FTIR) Spectrum. From X-Ray Diffraction (XRD) spectrum the particle size, d-spacing value and structure of the nanoparticle were analysed. Size of the nanoparticles and the elemental composition were detect...

In this research zinc oxide (ZnO) nano-crystalline powders were prepared by sol-gel method using zinc acetate. The ZnO nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), ultraviolet-visible (UV-Vis), Fourier transform infra-red (FT-IR) and energy dispersive X-ray (EDX) spectroscopy. The structure of nanoparticles was studied using XRD pattern. The c...