High harmonic generation (HHG) with longitudinal optical orbital angular momentum has attracted much attention over the past decade. Here, we present first study on HHG transverse driven by spatiotemporal vortex (STOV) pulses. We show that produced spatial-resolved spectra reveal unique structures, such as spatially spectral tilt and fine interference patterns. these spatiospectral structures originate from both macroscopic microscopic effect of singularity in HHG. Employing two-color...

Structured light has attracted great interest in scientific and technical fields. Here, we demonstrate the first generation of structured air lasing N2+ driven by 800 nm femtosecond laser pulses. By focusing a vortex pump beam at N2 gas, generate superfluorescent radiation 391 nm, which carries same photon orbital angular momentum as beam. With injection Gaussian seed coherent is amplified, but vorticity unchanged. A new physical mechanism revealed radiation: transfers spatial spiral phase...

We demonstrate a novel attoclock, in which we add perturbative linearly polarized light field at 400 nm to calibrate the attoclock constructed by an intense circularly 800 nm. This approach can be directly implemented analyze recent hot and controversial topics involving strong-field tunneling ionization. The generally accepted picture is that ionization instantaneous probability synchronizes with laser electric field. Alternatively, recently it was described Wigner would occur certain of...

Chirality is a phenomenon with widespread relevance in fundamental physics, material science, chemistry, optics, and spectroscopy. In this work, we show that free electron can be converted by the field cycles of laser light into right-handed or left-handed coil mass charge. contrast to phase-vortex beams, our electrons maintained flat de Broglie wave but obtained their chirality from shape expectation value space time. Measurements function densities attosecond gating revealed...

With the rapid development of femtosecond lasers, generation and application optical vortices have been extended to regime intense-light-matter interaction. The characterization orbital angular momentum (OAM) intense vortex pulses is very critical. Here, we propose demonstrate a novel photoelectron-based scheme that can in situ distinguish OAM focused without modification light helical phase. We employ two-color co-rotating circular fields strong-field photoionization experiment, which one...

The time delay of photoelectron emission serves as a fundamental building block to understand the ultrafast electron dynamics in strong-field physics. Here, we study angular streaking CO molecules by using two-color ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>400</mml:mn> <mml:mo>+</mml:mo> <mml:mn>800</mml:mn> </mml:math> nm) corotating circularly polarized fields. By coincidently measuring photoelectrons with dissociative ions, present molecular...

We study the strong-field ionization driven by quantum lights. Developing a quantum-optical-corrected approximation model, we simulate photoelectron momentum distribution with squeezed-state light, which manifests as notably different interference structures from that coherent-state (classical) light. With saddle-point method, analyze electron dynamics and reveal photon statistics of light fields endows tunneling wave packets time-varying phase uncertainty modulates intracycle intercycle...

The realization of spatiotemporal vortex structure various physical fields with transverse orbital angular momentum (OAM) has attracted much attention and is expected to expand the research scope open new opportunities in their respective fields. Here we present theoretically first, best our knowledge, study on generation attosecond pulse trains featuring a optical (STOV) by two-color femtosecond light field, each color carrying OAM. Through careful optimization relative phase intensity...

The formation and dynamics of fractional vortex charge in orbital-angular-momentum states is experimentally investigated. holographic lithography method developed this work may be effectively applied to study other structured matter waves.

Abstract Electrons detached from atoms by photoionization carry valuable information about light-atom interactions. Characterizing and shaping the electron wave function on its natural timescale is of paramount importance for understanding controlling ultrafast dynamics in atoms, molecules condensed matter. Here we propose a novel attoclock interferometry to shape image atomic photoionization. Using combination strong circularly polarized second harmonic weak linearly fundamental field,...

Strong field physics and quantum optics, two prosperous fields in modern science, have recently been connected with each other. Here, we study the effect of bright squeezed vacuum light thermal on above-threshold ionization. With strong-field approximation theory, reveal a decoherence phenomenon caused by statistics photons, which ionization could be degenerated into classical-like picture under light. This represents direct transition from wavelike nature to particlelike behavior...

We investigate the generation of high-order harmonics with arbitrary ellipticity using synthesized two-color (800-nm + 400-nm) cross-linearly-polarized laser fields. It is shown that one can realize control over harmonic by finely adjusting relative phase and crossing angle such Through analyzing time-frequency distributions quantum orbits radiations, we show helicity originated from unsymmetrical contribution between different released in 800-nm cycle. And, further reveal controllability...

We study multiphoton ionization of Kr atoms by circular 400-nm laser fields and probe its photoelectron dichroism with the weak corotating counterrotating at 800 nm. The unusual momentum- energy-resolved dichroisms from ${^{2}\mathrm{P}}_{1/2}$ ionic state are observed as compared those ${^{2}\mathrm{P}}_{3/2}$ state. identify an anomalous enhancement sidebands related to on momentum distribution when switching relative helicity two counterrotating. By performing two-color...

We propose a robust scheme of studying the strong interactions between free electrons and photons using topological photonics. Our study reveals that corner state can be used to enhance interaction light electron significantly. The quality factor cavity exceed 20 000 has very long lifetime even after pump pulse is off. And thus, platform enables us achieve without need for zero delay phase matching as in traditional photon-induced near-field microscopy (PINEM). This work provides new...

Toroidal vortex is a kind of novel and exotic structured light with potential applications in photonic topology quantum information. Here, we present the study on high harmonic generation (HHG) from interaction intense toroidal vortices atoms. We show that spatial distribution spectra reveal unique structures, which are kinds high-order topological because rotating driving fields transverse orbital angular momentum. Then that, by synthesizing optical longitudinal momentum, it able to...

Recently, the emergence of HP-PRRSV (Highly Pathogenic porcine reproductive and respiratory syndrome virus) exacerbation mixed infections PRRSV PCV have resulted in significant economic losses for Chinese pig industry. This study collected a total 226 samples suspected infection with aforementioned viruses from diverse farms seven urban districts central northern Guangdong Province between 2020 2022. The positive rates PRRSV, PCV2, PCV3 were 33.2%, 37.6%, 7.5%, respectively, there various...

The novel quantum effects induced by the free-electron-photons interaction have attracted increasing interest due to their potential applications in ultrafast information processing. Here, we propose a scheme generate optical cat states based on interference of multi-path interactions that take place simultaneously with strong coupling strength. By performing projection measurement electron, state light changes significantly from coherent into non-Gaussian either Wigner negativity or...

We measure the photoelectron momentum distributions of Ar atoms in cross-linearly-polarized two-color (800 nm+400 nm) laser field with an angle ${45}^{\ensuremath{\circ}}$. The are controlled by tuning phase synthesized fields. With semiclassical numerical simulation, we have analyzed subcycle dynamics tunneling electron wave packets and studied Coulomb effect on evolution packets. Our investigation indicates that effects strongly dependent trace electric after tunneling. focusing defocusing...

Probing and manipulating the electronic motion in ultrafast laser molecular interaction provides pathways for quantum imaging controlling chemical reactions. Recently, emerging application of attosecond metrology electron dynamics has accessed time scale most fundamental processes Here, we probe tunneling internuclear-dependent dissociative reaction ${\mathrm{H}}_{2}$ with angular streaking using two-color bicircularly polarized femtosecond pulses. By measuring high-resolution photoelectron...