The topological edge state (TES) and corner (TCS) in photonic crystals (PCs) provide effective ways to manipulate the propagation of light. To improve performance integration devices, realization multiband states by PCs combined with quasi-periodic structure needs be urgently explored. In this Letter, a Penrose-triangle (P-T) PC, which arranges basic structural unit 12-fold Penrose-type quasi-crystal (PQC) triangular lattice, is proposed. TES TCS at low- high-frequency bands can generated...

Abstract Abstract
Background: This study aimed to evaluate the effect of bad contact electrodes on quality electrical impedance tomography (EIT) data and reliability lung ventilation imaging.
Methods: Thirty healthy volunteers were examined using EIT under normal relaxed tidal breathing in a supine position. The five electrode-skin conditions (C1 C5) for electrode No. 2 defined by systematically varying area. Specifically, C1 represented full contact, C2 covered 25% surface,...

The models currently used in the detection of gravitational waves (GWs) either do not consider a relative motion between center mass source and observer or usually only its effect on frequencies GWs. However, it is known for light that changes but also brightness source, latter which called ``beaming effect.'' We investigate such an GWs find observed amplitude GW signal, unlike behavior light, monotonic function velocity responds differently to two polarizations. attribute difference...

Abstract Transient absorption spectroscopy is utilized extensively for measurements of bound- and quasibound-state dynamics atoms molecules. The extension this technique into the extreme ultraviolet (XUV) region with attosecond pulses has potential to attain unprecedented time resolution. Here we apply aligned-in-space XUV are much shorter than during which molecules remain aligned, typically $$&lt;$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mo>&lt;</mml:mo></mml:math>...

Laser-induced rotational wave packets of H_{2} and D_{2} molecules were experimentally measured in real time by using two sequential 25-fs laser pulses a reaction microscope. By measuring the time-dependent yields above-threshold dissociation enhanced ionization molecule, we observed few-femtosecond delay between channels for both D_{2}. The was interpreted reproduced classical model that considers thus additional interaction within pulse. We demonstrate accurately phase packet hydrogen can...

We demonstrate the measurement of field-free molecular alignment air can be realized by combining weak field polarization technique (WFPT) with a balanced detection system. The measured signal is proportional to parameter. Periodic revival structures transient and permanent between revivals detected clearly single high sensitivity. Fourier transform spectrum agrees well calculation result provides information populations different J states in rotational wave packet.

Abstract In gravitational-wave (GW) astronomy accurate measurement of the source parameters, such as mass, relies on waveform templates. Currently, templates are developed assuming that a source, stellar-mass binary black hole (BBH), is residing in vacuum. However, astrophysical models predict BBHs could form gaseous environments, common envelopes, stellar cores, and accretion disks active galactic nuclei. Here we revisit impact gas GW waveforms with focus early inspiral phase when frequency...

We report the successful design and experimental implementation of three coincident nonlinear interactions, namely ZZZ (type 0), ZYY I), YYZ/YZY II) second-harmonic generation 780 nm light from a 1560 pump beam in single, multigrating, periodically poled KTiOPO(4) crystal. The resulting medium is key component for making scalable quantum computer over optical frequency comb single parametric oscillator.

Ultrafast extreme ultraviolet (XUV) transient absorption spectroscopy measures the time- and frequency-dependent light losses after light–matter interactions. In linear region, matter response to an XUV field is usually determined by complex refractive index <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline" overflow="scroll"> <mml:mover accent="true"> <mml:mi>n</mml:mi> <mml:mo stretchy="true">˜</mml:mo> </mml:mover> </mml:math> . The signal directly related imaginary...

Air lasing in the nitrogen molecular ion is not well understood because complex physics responsible for gain interwoven with pulse propagation an extreme environment. Here we use a short gas jet to limit interaction length, thereby removing effects. We report on several mechanisms that contribute decay of different conditions, and experimentally isolate two timescales: long-term due collisional state mixing, short-term cannot be explained by population inversion. To test former, control...

Conducting a comprehensive molecular-level evaluation of photoacid generator (PAG) and its subsequent impact on lithography performance can facilitate the rational design promising 193 nm photoresist tailored to specific requirements. In this study, we integrated spectroscopy computational techniques meticulously investigate pivotal factors three prototypical PAG anions, p-toluenesulfonate (pTS−), 2-(trifluoromethyl)benzene-1-sulfonate (TFMBS−), triflate (TF−), in process. Our findings...

A near-infrared laser generates gain on transitions between the $B^{2}\mathrm{\ensuremath{\Sigma}}_{\text{u}}^{+}$ and $X^{2}\mathrm{\ensuremath{\Sigma}}_{\text{g}}^{+}$ states of nitrogen molecular cation in part by coupling $A^{2}\mathrm{\ensuremath{\Pi}}_{\text{u}}$ $V$ system. Traditional time resolved pump-probe measurements rely postionization pump pulse to initialize dynamics state. Here we show that a weak second excitation reduces ambiguity because it acts only ion independent...

High harmonic spectroscopy relies on high generation (HHG) in aligned molecules.The first step of HHG is the ionization molecule intense femtosecond laser field.Here we present measurements both yield and as a function molecular angle N 2 CO molecules.Measurements were done at two wavelengths, 800 1200nm, for range intensities, to study sensitivity conditions processes.The behavior was relatively insensitive conditions.However , minimum emission observed that sensitive intensity wavelength,...

We demonstrate experimentally that prealigned molecules produce observable spectral redshift or blueshift on the high-order harmonic generation. distinguish two effects of molecular alignment phase modulation harmonics; one is from gradient degree and other plasma density varied by alignment. The finding provides an insight distribution harmonics a method fine-tuning spectrum.

We report the observation of a $4.1\phantom{\rule{0.16em}{0ex}}\ifmmode\pm\else\textpm\fi{}\phantom{\rule{0.16em}{0ex}}0.2$ THz quantum beat in photoelectron spectrum molecular nitrogen following coherent optical excitation by 14 eV photons and probed two at 800 nm. The intermediate states pathway interference are valence state ${b}^{\ensuremath{'}}\phantom{\rule{4pt}{0ex}}^{1}\mathrm{\ensuremath{\Sigma}}_{u}^{+}\phantom{\rule{0.16em}{0ex}}v=13$ Rydberg...

Abstract An extreme-ultraviolet (XUV) laser pulse consisting of harmonics a fundamental near-infrared (NIR) frequency is combined with the NIR to systematically study two-color photoionization helium atoms. A time-resolved photoelectron spectroscopy experiment carried out where energy- and angle-resolved distributions are obtained as function intensity wavelength. Time-dependent Schrödinger equation calculations performed for conditions corresponding used extract residual populations Rydberg...

The self-focusing of few-cycle pulses at the wavelength 1800 nm under different focusing conditions and polarization states is experimentally investigated. critical power nonlinear refractive index for linearly circularly polarized are determined. value found much larger than that multi-cycle pulses, which consistent with previous result on 800 nm.

We demonstrate experimentally that in pump-probe experiment of H2 fragmentation by intense laser fields, the Coulomb explosion (CE) paths induced second ionization dissociating H2+ show varied dependencies on intensity. While charge resonance enhanced (CREI) channel is intensity dependent, probe CE (PICE) independent at certain delay time. By using a classical model, we calculated dissociation trajectories which agree well with experimental data.

We report on an optical amplification and energy threshold of the two most prominent emission lines, 391.4 427.8 nm, cavity-less lasing nitrogen ions pumped by femtosecond laser pulses. It was found that transitions both show under a low gas pressure condition, while nm is barely amplified high pressure. Moreover, presents significant lower pump larger gain factor than emission. Numerical simulations based three-state coupling model suggest smaller ionization Franck-Condon from ground state N

Development of attosecond laser technology allows us to measure electron dynamics such as photoionization delays between different species or electronic states. In general, the measured phase is a mixture spectral extreme ultraviolet (XUV) pulse and atomic phases inherent optical transitions. Hence, it difficult disentangle these independently. Here we separate by using an XUV train containing both even odd harmonic orders, generated 800- 400 nm pulse, in presence infrared 800-nm pulse. We...

Atomic clusters presents an isolated system that models the bulk materials whose mechanism of HHG remains uncertain, and a promising medium to produce beyond limited conversion efficiency for gaseous atoms. Here we reveal oscillation collective electron motion within develops after interaction intense laser fields, it significantly enhances harmonic dipole increases quantum phase harmonics. Experimentally, matching conditions from nanometer xenon atoms are distinguished, which confirms...