Hot electron generation in a dense plasma by femtosecond laser pulses of subrelativistic intensity

Femtosecond laser-plasma interaction with prepulse-generated liquid metal microjets

“…We also compared hard x-ray yields from Ga and Cu plasmas (the latter measurements were made with a flat solid copper target in the same setup as in Ref. 35). The x-ray production efficiency is somewhat lower (approximately 50%) for the Ga target than for the Cu target, which can be explained by the lower Cu K-shell binding energy.…”

“…We note that this was not the case with flat solid Si targets, where the energy E aver hot slowly decreased with the contrast C, while the mean-energy E hot spread was small (the same as for the melted Ga target at the highest C value) and was independent of the C value. 35 Hence, a considerable increase in the number and mean energy of hot electrons should be attributed to some specific behavior of the melted Ga target in the presence of a prepulse of a certain intensity. The presence of a nanosecond prepulse does not affect the main laser pulse peak intensity, and new interaction physics should, therefore, be involved for a melted Ga target perturbed by the prepulse.…”

“…This value agrees well with both the present data and our previous results obtained under the same conditions but using dielectric solid targets (flat silicon and quartz plates). 35 In the case of s-polarized laser light interacting with a flat plasma surface, the resonance absorption mechanism is negligible. 2 A significant absorption of the s-polarized laser pulses indicates a strong modification of the target surface.…”

Amplification and Generation of Frequency-Modulated Soliton Pulses in Nonuniform Active Fiber Configurations

“…The critical part of laser physics is the development of ultrashort pulse generators (USPs), which provide a high peak radiation power [1,2]. Extremely high concentration of energy, broadband optical spectrum, and extremely short time of light emission [3][4][5] make the ultrashort pulse (USP) of great interest for many applications such as processing and modification of materials, laser micro-and nanostructuring of materials, and nuclear and accelerator technologies [1,2,[5][6][7][8][9][10][11]. Furthermore, high-frequency fiber lasers of USP with a repetition rate over 1 GHz are fabulous candidates for the development of radiophotonics technologies [12][13][14].…”