Nanoscale morphology, optical dynamics and gas sensor of porous silicon.

We investigated the multifaceted gas sensing properties of porous silicon thin films electrodeposited onto (100) oriented P-type silicon wafers substrates. Our investigation delves into morphological, optical properties, and sensing capabilities, aiming to optimize their use as efficient gas sensors. Morphological analysis revealed the development of unique surfaces with distinct characteristics compared to untreated sample, yielding substantially rougher yet flat surfaces, corroborated by Minkowski Functionals analysis.

Advanced nano-texture, optical bandgap, and Urbach energy analysis of NiO/Si heterojunctions.

Due to the large number of industrial applications of transparent conductive oxides (TCOs), this study focuses on one of the most important metal oxides. The RF-magnetron sputtering method was used to fabricate NiO thin films on both quartz and silicon substrates at room temperature under flow of Argon and Oxygen. The sputtered samples were annealed in N atmosphere at 400, 500, and 600 °C for 2 hours.

All-optical flip-flop based on nonlinear effects in fiber Bragg gratings.

We demonstrate a novel design for a passive all-optical R-S flip-flop with separate set-rest ports based on nonlinearity in the fiber Bragg gratings (FBGs). The spectrum of FBGs in the presence of the Kerr effect is investigated, and cw and transient characteristics of nonlinear-induced bistability of the passive distributed feedback structures are studied by numerical solving of coupled-mode equations. It is shown that a pulse with a pulsewidth of 0.

Beam shaping design for coupling high power diode laser stack to fiber.

A beam shaping technique that rearranges the beam for improving the beam symmetry and power density of a ten-bar high power diode laser stack is simulated considering a stripe mirror plate and a V-Stack mirror in the beam shaping system. In this technique, the beam of a high power diode laser stack is effectively coupled into a standard 550 μm core diameter and a NA=0.22 fiber.

Necklace-shaped Au-Ag nanoalloys: laser-assisted synthesis and nonlinear optical properties.

Here in this paper, necklace-shaped Au-Ag nanoalloys (NAs) have been synthesized by a laser-based approach. A chain of Ag nanoparticles (NPs), which were joined together with Au junctions, was formed upon copper vapor laser (CVL) irradiation of a colloidal mixture of Ag and Au NPs; while the corresponding NPs were separately provided by laser ablation of gold and silver targets in deionized water by a 1064 nm Q-switched Nd:YAG laser. Dependence of the NAs development process on the CVL irradiation time in three distinct stages of as-mixed, nucleation and complete formation has been systematically studied by UV-vis optical absorption spectroscopy analysis as well as by transmission electron microscopy (TEM), which was exploited to visually confirm the NAs evolution through the process.

Dynamical stable cavity of side-pumped thin-disk laser with slanted sides.

In this article, we use the results of finite-element analysis (FEA) of temperature distribution, deformation, and stress to provide a full three-dimensional simulation of a dynamically stable cavity by propagating wavefront into hot, thermally deformed Yb:YAG/YAG thin-disk laser, using the fast Fourier transform (FFT) split-step beam propagation method (BPM). The wave optics computation therefore delivers realistic results for important features of a laser-like intensity, phase profile, and resonator eigenvalues and higher order-eigenmodes of the laser beam.