Influence of piezoelectricity, doping and magnetostatic field on Brillouin amplification in compound (AIIIBV and AIIBVI) semiconductors

A theoretical formulation followed by numerical analysis describing Brillouin amplification in compound (AIIIBV and AIIBVI) semiconductors is explored. The threshold condition for the onset of Brillouin amplification is determined. Well above the threshold intensity, the influence of piezoelectricity, doping concentration, and external magnetostatic field on the parameters characterizing Brillouin amplification viz. Brillouin amplification coefficient, transmitted intensity of Brillouin-scattered Stokes mode (BSSM), and Brillouin cell efficiency of the Brillouin cell isestimated. Numerical analysis is made for three different Brillouin cells consisting of [Formula: see text]-InSb, [Formula: see text]-GaAs, and [Formula: see text]-CdS, at 77[Formula: see text]K duly irradiated by a pulsed CO2 laser. Efforts are directed towards to determine appropriate values of doping concentration and magnetostatic field to enhance the parameters characterizing Brillouin amplification, at lower excitation intensity, and to establish the suitability of compound semiconductors as hosts for fabrication of efficient Brillouin amplifiers.

Optical Sensing of TiO2 Nanofluid for Self Stability

Nanofluids are colloidal suspensions of nanoparticles in a base fluid which are mainly used as modern heat transfer fluids. The applications of nanofluids include electronic cooling systems, direct absorption solar collectors, magnetic smart fluids and in biomedical treatments. The success of these applications depends on stability of nanofluid. In the present work TiO2nanofluids have been synthesized by two step technique .The nanoparticle of TiO2are prepared by sol gel and characterized by XRD, SEM and UV. The sedimentation of prepared nanofluid is observed by the gravity sedimentation method and transmitted intensity is recorded by a photo detector. A profile between the transmitted intensity and distance of nanofluid from laser source is obtained which shows the potential application of nanofluid as optical sensors for detecting stability of nanofluid.

Anti-Reflective Structure of PMMA/Glass Fiber Membrane Produce by Argon Plasma Etching and Variation of Transmitted Intensity

The aim of this research is to increase the membrane’s transmitted intensities; it used Argon plasma etching to process the anti-reflective structure on PMMA/glass fiber membrane surface. The anti-reflective structure could increase the light transmission at the identical specification of membrane’s basic cloth. Membrane’s transmitted intensities can directly affect it products competitiveness. The parameter of experimentation set with distance between sample and RF plate are 19 or 5.5 centimeters, plasma output power is 270, 240, 210 Watt respectively, each process time is 6, 12, 18, 24, 30 seconds. In this stage, the best transmitted intensity of parameter is 19cm, 210W, 30sec; it increased 2.4 % than non-treatment sample. The summary of this study, decreased plasma output power would reduce the impact extent of plasma gas but uniformity of structure should increase. Decreased the distance between sample and RF plate can avoided the degeneration of energy, reinforced the problem of insufficient etching and reduced the turbulence.

Magnification—a New Look at a Long-known Optical Property of Dentin

Light propagation in human dentin exhibits a strong directional dependence featuring the long-known optical magnification property. We hypothesized that this anisotropic effect is caused by multiple scattering at the dentin tubules, and not by fiberoptic effects, as had been previously assumed. We performed measurements of the transmitted intensity from dentin disks and compared them with Monte Carlo simulations of light propagation in dentin, considering the scattering by the tissue’s microstructure. We found that the optical anisotropy of dentin can be fully explained with this model. We concluded that the magnification property of dentin is due to multiple scattering by the dental microstructure.