In this paper, we investigate the effects of auto-tracking subsystem together with different beam divergences on SNR, BER and stability of FSO communication links. For this purpose we compute the values of power, SNR and BER on receiver, based on analytic formula of Gaussian beam on receiver plane. In this computation the atmospheric effects including absorption, scattering and turbulence are c...

This tutorial survey paper reviews several different models for light interaction with volume densities of absorbing, glowing, reflecting, and/or scattering material. They are, in order of increasing realism, absorption only, emission only, emission and absorption combined, single scattering of external illumination without shadows, single scattering with shadows, and multiple scattering. For e...

Artisanal and Small-scale Gold Mining (ASGM) within the Amazon region has created several environmental impacts, such as mercury contamination and changes in water quality due to increased siltation. This paper describes the effects of water siltation on the underwater light environment of rivers under different levels of gold mining activities in the Tapajós River Basin. Furthermore, it invest...

in this research, the coupling between non-gray radiation and separation convection flow in a duct is investigated numerically. distributions of absorption coefficients across the spectrum  are obtained from the hitran2008 database. the full-spectrum k-distribution method is used to deal with the non-gray part of the problem, while the gray radiation calculations are performed using the planck ...

a novel quaternary ammonium-based cationic gemini surfactant (s6) having 1,6 di-bromo hexane as a spacer, have been used and its interaction with insulin in aqueous solution (ph, 7.40) was investigated by several methods including fluorescence spectroscopy, uv-vis spectroscopy, circular dichroism, dynamic light scattering, ζ-potential measurements, conductivity and transmission electron microsc...

One major problem of the conventional solar cells is low conversion efficiency. In this work, we have proposed a new design including hemisphere texturing on top and metallic plasmonic nanostructure under the silicon layer to enhance the optical absorption inside the photosensitive layer.    The finite-difference time-domain (FDTD) method has been used to investigate the interaction of light wi...

Production of nanoparticles has been attractive by biological based fabrication as an alternative to physical and chemical approaches due to exceeding need to develop safe, reliable, clean and eco-friendly methods for the preparation of nanoparticle for pharmaceutical and biomedical applications. In the present study, biogenic tellurium nanoparticles (TeNPs) were successfully prepared using pot...

Complete statistical randomization of the direction of propagation of light trapped in semiconductor films can result in a large absorption enhancement. We have employed a calorimetric technique, photothermal deflection spectroscopy, to monitor the absorption of alpha-SiH(x) films textured by the natural lithography process. The observed enhancement factors, as high as 11.5, are consistent with...