Steering Laser-Produced THz Radiation in Air with Superluminal Ionization Fronts

Physical Review Letters, Journal Year: 2025, Volume and Issue: 134(4)

Published: Jan. 29, 2025

We demonstrate that pulsed THz radiation produced in air by a focused ultrashort laser pulse can be steered to large angles or even the backward direction with respect propagation axis. The emission angle is adjusted flying focus technique, which determines speed and of ionization front created single-color pulse. This easily adjustable source, being well separated from intense laser, opens exciting applications for remote spectroscopy.

Language: Английский

Femtosecond laser-induced plasma filaments for beam-driven plasma wakefield acceleration

Physical review. E, Journal Year: 2025, Volume and Issue: 111(2)

Published: Feb. 18, 2025

We describe the generation of plasma filaments for application in plasma-based particle accelerators. The complete characterization a filament generated by low-energy self-guided femtosecond laser pulse is studied experimentally and theoretically low-pressure nitrogen gas environment. For this purpose, we adopted spectroscopic methodology to measure density electron temperature. In addition this, also employed side-imaging technique retrieve column sizes (length diameter). measurements show stable $\ensuremath{\approx}4\text{\ensuremath{-}}\mathrm{cm}$-long with $\ensuremath{\approx}300\phantom{\rule{0.16em}{0ex}}\textmu{}\mathrm{m}$ diameter. peak temperature are ${n}_{e}\ensuremath{\approx}{10}^{16}\phantom{\rule{4pt}{0ex}}{\mathrm{cm}}^{\ensuremath{-}3}$ ${T}_{e}\ensuremath{\approx}1.3\phantom{\rule{0.16em}{0ex}}\mathrm{eV}$, respectively, decay time approximately 8 ns. that experimental results agreement numerical simulations terms size time.

Language: Английский

Pulse repetition-rate effect on the critical power for self-focusing of femtosecond laser in air

Optics Express, Journal Year: 2024, Volume and Issue: 32(16), P. 28048 - 28048

Published: July 9, 2024

The femtosecond laser filamentation is of significant interest due to its remarkable characteristics, and determining the critical power self-focusing essential for process filamentation. In this work, intense pulses at different repetition rates experimentally measured according focus-shift method. A bimodal fitting method proposed more accurately determine power. It found that decreases as rate increases. numerical simulation based on modified nonlinear Schrödinger equation effectively explains experimental results obtained. This work provides valuable insights generation application high

Language: Английский