Phys.org May 28, 2024
Terahertz (THz) waves can ionize atoms and molecules when a sufficiently large number of THz photons are concentrated in time and space. An international team of researchers (South Korea, USA – University of Maryland) demonstrated the generation of ionizing, multicycle, 15-THz waves emitted from large-area lithium niobate crystals via phase-matched optical rectification of 150-terawatt laser pulses. A complete characterization of the generated THz waves in energy, pulse duration, and focal spot size showed that the field strength could reach up to 260 megavolts per centimeter. The intense THz pulses were irradiated onto various solid targets to demonstrate THz-induced tunneling ionization and plasma formation. The study also discussed the potential of nonperturbative THz-driven ionization in gases, which will open new opportunities, including nonlinear and relativistic THz physics in plasma… read more. Open Access TECHNICAL ARTICLE
Strong-field THz sources. Credit: Light: Science & Applications volume 13, Article number: 118 (2024)