High harmonic generation in Ne and H_2 gas mixtures

Abstract

High harmonic generation (HHG) enables the production of coherent light in the extreme-ultraviolet (XUV) spectral region. However, the radiation conversion efficiency from infrared to the XUV is low. We observed enhancement of HHG in gas mixtures of H 2 and Ne compared to pure gases H 2 or Ne. Our experiments show that at an intensity of ∼1.5 × 10 14 W∕cm 2 and in mixtures of gases with significantly different ionization potentials (IPs), the initial HHG takes place in the component with lower IP (H 2 ), inducing excited states and facilitating ionization and HHG in the component with higher IP (Ne). We show that the combination of the two gas components results in an enhancement or suppression of the output of high harmonics as compared to pure gases, which is also confirmed by the employed phenomenological model.

Optical Harmonic Generation in 2D Materials

“…[ 61 ] Traditionally, HHG is observed in various bulk crystals such as ZnO, [ 75 ] Si, [ 76 ] and GaSe, [ 77 ] liquid phases, [ 78 ] and the rare‐gas phases such as, Ar and Ne. [ 79–83 ] Theoretical analysis shows that HHG is linked with electron dynamics within the materials. Therefore, strong many‐body interactions, electronic properties, and reduced interlayer screening make 2D materials an ideal platform to observe HHG processes.…”

N2 Molekülünden ve Bunun Ne Gazı ile Karışımından Sub-terawatt Lazer Sistemi kullanılarak Uyumlu XUV Radyasyonu Üretilmesi

“…The central wavelength of the driving laser field is centered at 800nm (IR). The radiation is focused by using a 40cm focal length lens (FL), and the focused intensity of the field is 1×10 15 W/cm 2 . The radiation is focused on a gas needle (gas jet) containing pure N2 gas or its mixture with Ne.…”

“…The state-of-the-art laser system finds applications from pump-probe spectroscopy [1] to the study of laser beam shape [2][3][4][5], and from terahertz science [6,7] to fragmentation [8,9]. Moreover, it paves the way for high-intensity physics (high harmonic generation) [10][11][12][13][14][15][16]. There are facilities producing high photon energy such as free electron lasers and synchrotron sources [17,18], but these facilities have some disadvantages such as high cost to operate and not reachable by the researchers working in moderate laboratories.…”

“…Although high harmonic generation has the potential candidate provide bright short optical pulses, it suffers from its low conversion efficiency [28,29]. Optimization of harmonic generation yield has been studied by several researchers [12][13][14][15][30][31][32][33]. The brightness of such a light source is a benchmark for studying light-matter interaction.…”