Continuous-wave laser oscillations in LiF:F-2 crystal optically pumped by a laser diode at 970 nm were demonstrated for what is believed to be the first time. The slope efficiency of 14% and conversion efficiency of 5.5% were achieved for 80 micros pump pulse duration and 5 Hz pulse repetition rate. An efficiency twice as low was measured at a 6.25 kHz pulse repetition rate (50% off-duty factor) and in cw mode of laser operation.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1364/ol.31.002154 | DOI Listing |
Sensors (Basel)
December 2024
Mines Saint-Etienne, Centre CMP, Département BEL, F-13541 Gardanne, France.
The primary method of treatment for patients suffering from drug-resistant focal-onset epilepsy is resective surgery, which adversely impacts neurocognitive function. Radio frequency (RF) ablation and laser ablation are the methods with the most promise, achieving seizure-free rates similar to resection but with less negative impact on neurocognitive function. However, there remains a number of concerns and open technical questions about these two methods of thermal ablation, with the primary ones: (1) heating; (2) hemorrhage and bleeding; and (3) poor directionality.
View Article and Find Full Text PDFDiagnostics (Basel)
December 2024
Department of Neurosurgery, Carle Foundation Hospital, Urbana, IL 61801, USA.
Microcirculation is an essential system that regulates oxygen and nutrients to cells and tissues in response to various environmental stimuli and pathophysiological conditions. Diabetes mellitus can cause microvascular complications including nephropathy, neuropathy, and retinopathy. The pathogenesis of microvascular dysfunction in diabetes is associated with hyperglycemia and the result of an interplay of various factors.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-intense Laser Science, Shanghai Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Shanghai, 201800, China.
We have observed the Berry phase effect associated with interband coherence in topological surface states (TSSs) using two-color high-harmonic spectroscopy. This Berry phase accumulates along the evolution path of strong field-driven electron-hole quasiparticles in electronic bands with strong spin-orbit coupling. By introducing a secondary weak field, we perturb the evolution of Dirac fermions in TSSs and thus provide access to the Berry phase.
View Article and Find Full Text PDFNat Nanotechnol
January 2025
Wellman Center for Photomedicine, Massachusetts General Hospital, Cambridge, MA, USA.
The ultimate limit for laser miniaturization would be achieving lasing action in the lowest-order cavity mode within a device volume of ≤(λ/2n), where λ is the free-space wavelength and n is the refractive index. Here we highlight the equivalence of localized surface plasmons and surface plasmon polaritons within resonant systems, introducing nanolasers that oscillate in the lowest-order localized surface plasmon or, equivalently, half-cycle surface plasmon polariton. These diffraction-limited single-mode emitters, ranging in size from 170 to 280 nm, harness strong coupling between gold and InGaAsP in the near-infrared (λ = 1,000-1,460 nm), away from the surface plasmon frequency.
View Article and Find Full Text PDF3D Print Addit Manuf
October 2024
Department of Aircraft Manufacturing Engineering, School of Aerospace Engineering, Guizhou Institute of Technology, Guiyang, China.
The application of a pulsed magnetic field (PMF) during a metallurgy solidification process has proven to be an effective method in refining the grain size and improving the mechanical performance of the material. However, fewer works were reported in the realm of laser additive manufacturing (LAM) and the mechanism of grain refinement consequent to the PMF is still unclear. In this work, numerical models were developed to study the thermal-fluid characteristics in the Ti-alloy melt pool generated during the laser scanning process under the effect of a combined direct current (DC) electric field and PMF.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!