We observe the complete dynamics of propagation very intense, femtosecond laser pulses in air under tight focusing conditions via direct imaging entire interaction zone. The whole life history focused is then reconstructed by means numerical simulations. show that beam breakup leads to a dual-rate increase filament numbers with power. Linearly and circularly polarized give rise fusion governed external conditions. For conditions, intensity saturation due plasma generation nonlinear losses...

The nonlinear optical properties and the role of surface-plasmon resonance (SPR) on limiting (OL) Ag–Cu nanoclusters co-doped in SiO2 matrix prepared using sol-gel technique with a Cu∕Ag molar ratio 1, 2 3, respectively, are presented. studies were made second harmonic high-power nanosecond picosecond Nd:YAG lasers. These films show self-defocusing nonlinearity both pulses good absorption behavior pulse excitation. refractive index decreased decreasing particle size, whereas increased an...

We present measurements of the supercontinuum emission (SCE) from ultrashort Ti:Saph laser pulse filamentation in air a tightly focused geometry. The spectral broadening SCE indicates that peak intensities exceed clamping value few 10(13) W/cm(2) obtained for loose focusing geometry by at least one order magnitude. provide an interpretation this regime filamenation without intensity clamping.

The third order nonlinear optical properties of two different sized ZnSe and ZnSe∕ZnS quantum dots (QDs) are investigated. absorption is measured at 806nm using Ti:sapphire 100fs laser pulses in an open aperture Z-scan setup. Two-photon (2PA) found to be dominant core shell QDs. 2PA cross section enhanced by three orders magnitude compared bulk ZnSe. observed increase with reduction QD diameter, due strong confinement effect. QDs exhibit higher corresponding QDs, indicating better...

In the present work, effect of CaO/P2O5 ratio on composition sol-gel synthesized 58SiO2-(19 − x)P2O5–(23 + x)CaO (x = 0, 5, 10 and 15 mol%) glass samples was studied. Further, NBO/BO hydroxy carbonated apatite layer (HCA) forming ability based dissolution behavior in simulated body fluid (SBF) solution also investigated. ratios were 1.2, 2, 3.6, 9.5, respectively. obtained using Raman spectroscopic analysis as 0.58, 1.20, 1.46, 1.78, All soaked SBF for 7 days. The calculated weight losses...

ZnSe and ZnSe∕ZnS core/shell quantum dots (QDs) of two different sizes (4.5 3.5nm) have been synthesized. The nonlinear absorption is measured at 1064nm using a 35ps laser with an open aperture Z-scan setup. Three-photon (3PA) has observed in QDs. 3PA cross section found to be about four orders magnitude larger than bulk ZnSe, three higher ZnS increased QDs decreasing size from 4.5to3.5nm, due strong confinement effect.

Abstract We present our results on spatio-temporal evolution of laser plasma produced shockwaves (SWs) and hot core (HCP) created by focused second harmonic (532 nm, 7 ns) Nd-YAG in quiescent atmospheric air at f/#10 focusing geometry. Time resolved shadowgraphs imaged with the help an ICCD camera 1.5 ns temporal resolution revealed presence two co-existing sources simultaneously generating SWs. Each independently led to a spherical SW following Sedov-Taylor theory along propagation...

Abstract: This paper unveils a revolutionary stacked microstrip antenna design that packs punch, delivering impressive gains in compact package. By harnessing the power of IE3D software and carefully selecting FR4 substrate with copper ground plane, we've crafted 2.4 GHz that's perfect for Wi-Fi applications. Our innovative outperforms traditional antennas, paving way exciting new possibilities wireless communication, IoT devices, beyond. research opens doors to high-gain, antennas meet...

We demonstrate that carbon nanotube coated surfaces produce two orders of magnitude brighter hard x-ray emission, in laser produced plasmas, than planar surfaces. It is accompanied by three reduction ion debris which also low Z and nontoxic. The increased emission a direct consequence the enhancement local fields via simple well known "lightning rod" effect. propose this source simple, inexpensive, high repetition rate point for variety applications imaging, lithography, microscopy, material...

Acoustic shock waves (ASWs) in the frequency range of 30-120 kHz generated during laser-induced breakdown (LIB) ambient air using 7 ns and 30 ps pulse durations are studied. The specific peak amplitudes observed to be different for nanosecond (ns) picosecond (ps) LIB. ASW frequencies ps-LIB lie between 90 120 with one dominant peak, whereas ns-LIB, two peaks 30-70 80-120 observed. These laser intensity dependent. With increasing energy pulses, acoustic move toward audible range. variation...

A two-dimensional axis symmetric hydrodynamic model was developed to investigate nanosecond laser induced plasma and shock wave dynamics in ambient air over the input energies of 50–150 mJ time scales from 25 ns 8 μs. The formation localized hot spots during energy deposition, asymmetric spatio-temporal evolution, rolling, splitting observed simulations were good agreement with experimental results. formed have two regions: core outer region. expansion due variation thermodynamic variables...

Multiplex ligation-dependant probe amplification (MLPA) is a highly sensitive and rapid alternative to multiplex polymerase chain reaction (PCR). Muscle biopsy should be reserved for mutation-negative cases.An attempt was made compare the sensitivity pattern of mutations by mPCR MLPA testing in cohort with suspected Duchenne muscular dystrophy (DMD). Eighty-three children DMD were enrolled testing. MLPA-negative cases underwent muscle immunohistochemistry (IHC) dystrophin.Mean age onset 45.3...

Energy dependent evolution of Stokes and anti-Stokes lines ice VII via forward stimulated Raman scattering (FSRS) during propagation a 30 ps laser pulse through liquid water, confirming structural change over GPa pressure range, is studied. Self-focusing the intense pulses observed to ionize medium generating free electrons that dominate SRS signals. The confinement plasma-generated by filamentation enhance signature modes reducing threshold.

We show that an attempt to synthesize nanocrystal alloys of Cd1−xZnxSySe1−y in a single-step reaction leads naturally heterostructured system with CdSe-rich core and CdS−ZnS hybrid shell because differences chemical reactivities the different constituents. These nanocrystals exhibit very high (∼65%) photoluminescence (PL) efficiency. The band-edge excitonic energy corresponding emission can be tuned over range visible spectrum by changing composition. samples strong two-photon absorption...

Optical limiting performance, third-order nonlinearity chi(3), and nonlinear absorption properties have been investigated in a new class of azoarene phosphorus (V) porphyrins with charge transfer (CT) states. The introduction axial groups into the porphyrin structure is found to reduce threshold by factor 2 lead rise second hyperpolarizability 1 order magnitude picosecond time regime orders nanosecond regime. experimental data show reverse saturation above fluence 0.5 J/cm2 presence CT state...

Evolution of acoustic shock wave (ASW) properties generated during nanosecond (ns) and picosecond (ps) laser-induced breakdown (LIB) atmospheric air at different input intensities is presented. The intensity varied by changing the focal geometry ns ps pulses. ASW pressures are observed to follow dynamic interplay between plasma density recombination species. conversion laser energy has increased from loose tight focusing conditions. central frequencies have moved toward lower side with...