Saturation absorption experiments are conducted on the title compound at 1.064 μm with laser light propagating along both [001] and [111] crystallographic axes. Rotation of crystals about these axes during reveals that transmission polarized radiation is highly anisotropic in saturation regime. The details anisotropy curves explained using a simple model subsets optical centers relevant set rate equations. ground excited-state cross sections calculated to be σgs=5.7(±2)×10−18 cm2...

We present a spectroscopic overview of ${\mathrm{Cr}}^{4+}$-doped ${\mathrm{Y}}_{3}$${\mathrm{Al}}_{5}$${\mathrm{O}}_{12}$ (YAG), new laser material for the near-infrared region (NIR). It is found that only 2% Cr ions are tetrahedrally coordinated ${\mathrm{Cr}}^{4+}$. However, optical spectra dominated by this ion. The missing inversion symmetry tetrahedral site causes higher cross sections than common octahedrally ions. experimental data include survey absorption and emission features....

We report on the performance of a Cr/sup 4+/:YAG laser, tunable over range from 1.32 to 1.53 mu m, under different operating conditions. Laser action has been achieved by pumping with Nd:YAG laser in Q-switched mode and cw Cr:Nd:GSGG long pulse mode. Slope efficiencies up 22% have achieved. The lowest threshold was 30 mJ for pumped Excited state absorption seems limit tuning output characteristics.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML"...

An unusual almost flat broadband plasmonic absorption, ranging from 400nm to well beyond 2500nm, was observed in a 150nm thin film of Ag nanoparticles embedded Teflon AF® matrix. The nanocomposites were synthesized by simple single-step vapor-phase codeposition method. various sizes and shapes, thus resonance frequencies, form fractal percolating network. attributed plasmon excitations within the nanoparticles, could be useful for multicolor applications visible infrared wavelengths region.

Luminescent nanophase europium-doped ZrO2 precursors are subjected to pyroprobe heating with nominal rates of 20 000 °C/s for 1 and 10 s various temperatures. When heated above the crystallization temperature, material forms tetragonal monoclinic polymorphs. Optical spectroscopy is used measure excitation spectra, fluorescence lifetimes samples. These optical signatures evaluated their potential as temperature indicators short events. The intensity ratio two peaks appear be promising...

One of the main limitations utilizing optimal wavefront shaping in imaging and authentication applications is slow speed optimization algorithms currently being used.To address this problem we develop a micro-genetic algorithm (µGA) for shaping.We test abilities µGA make comparisons to previous (iterative simple-genetic) by using each optimize transmission through an opaque medium.From our experiments find that faster than both iterative simple-genetic genetic are more resistant noise sample...

One of the primary difficulties in implementation organic-dye-based random lasers is tendency organic dyes to irreversibly photodecay. In this letter we report observation "reversible" photodegradation a Rhodamine 6G and ZrO$_2$ nanoparticle doped polyurethane laser. We find that during degradation emission broadens, redshifts, decreases intensity. After system observed self-heal leading returning its pristine intensity, giving recovery efficiency 100%. While peak intensity fully recovers,...

Spatial light modulator (SLM) controlled transmission of through opaque media is a relatively new experimental method with wide applications in various fields. While there has been surge research into the technique, little work reported considering effects parameters on efficiency optimization. In this study, we explore conditions optimization and find that intensity enhancement depends number modulated channels, phase steps, feedback integration radius, beam spot size, active SLM area. We...

Luminescent europium-doped Y2O3 precursors are evaluated as potential ex situ thermal sensors for rapid heating events. The material is heated via pyroprobe periods between 1 and 100 s. morphological optical properties of the measured a function temperature dwell time. Upon heating, believed to transform according Y2(CO3)3 → Y2O(CO3)2 Y2O2CO3 Y2O3, with transition crystalline phase occurring at about 666 °C. spectra heat-treated samples reflect presence amorphous components. peak excitation...

Optical physical unclonable functions (O-PUFs) are materials containing a large number of randomly distributed degrees freedom that can be probed optically. We develop tamper-indicating O-PUF seals using polyurethane adhesives with dispersed nanoparticles, where authentication is performed by use wavefront-shaping controlled reflection. test the material's and method's ability tampering attacks including: mechanical, thermal, chemical attacks, results demonstrating material/method's robust...