98%
921
2 minutes
20
The evolution of the filamentation of a femtosecond laser pulse in air is measured. The divergence of the filament core is almost constant over a long distance, encompassing a zone with efficient ionization followed by another where ionization is much weaker. At the end, the core diverges out linearly with a low divergence due to self-spatial filtering.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/ol.32.003477 | DOI Listing |
Phys Rev Lett
August 2025
University of Delaware, Department of Physics and Astronomy, Newark, Delaware 19716, USA.
Ultrafast light-driven strongly correlated antiferromagnetic insulators, such as prototypical NiO with a large Mott energy gap ≃4 eV, have recently attracted experimental attention using photons of both subgap [H. Qiu et al., Nat.
View Article and Find Full Text PDFACS Nano
September 2025
School of Physics and Key Lab of Quantum Materials and Devices of the Ministry of Education, Southeast University, Nanjing 211189, P. R. China.
While hexagonal boron nitride (hBN) hosts promising room-temperature quantum emitters for hybrid quantum photonic circuits, scalable deterministic integration and insufficient brightness alongside low photon collection and coupling efficiencies remain unresolved challenges. We present a femtosecond laser nanoengineering platform that enables the site-specific generation of hBN single-photon source (SPS) arrays. First-principles density functional theory (DFT) calculations and polarization-resolved spectroscopy confirm the atomic origin of emission as interfacial defects at hBN/SiO heterojunctions.
View Article and Find Full Text PDFPhys Rev Lett
August 2025
University of Konstanz, Department of Physics and Center for Applied Photonics, D-78457 Konstanz, Germany.
Femtosecond laser excitation of nanometer thin heterostructures comprising a heavy metal and a magnetically ordered material is known to result in the emission of terahertz radiation. However, the nature of the emitted radiation from heavy metal/antiferromagnet heterostructures has sparked debates and controversies in the literature. Here, we unambiguously separate spin and charge contributions from Pt/NiO heterostructures by introducing an unprecedented methodology combining high external magnetic fields with a symmetry analysis of the emitted terahertz polarization.
View Article and Find Full Text PDFClin Ophthalmol
September 2025
Department of Ophthalmology and Optometry, Medical University of Vienna, Vienna, Austria.
Purpose: To compare postoperative astigmatism and visual acuity (VA) outcomes in patients undergoing penetrating keratoplasty (PK) using a liquid-interface femtosecond laser (LI-fs) trephination and a conventional vacuum-trephine (VT) technique.
Methods: Our single-center, retrospective data analysis included 121 eyes (121 patients) treated between April 2014 and November 2022. Patients received PK either with a LI-fs or a VT system.
J Refract Surg
September 2025
Purpose: To discuss the technique and outcome of what the authors called the "flap-in-flap" technique and report its safety as a procedure for correction of post-laser in situ keratomileusis (LASIK) myopic regression.
Methods: Seven eyes of 4 patients were included in this study. All patients had previously undergone LASIK for compound myopic astigmatism using the Moria M2 micro-keratome (Moria) 8 to 12 years prior to presentation.