Resonant structures in the low-energy electron continuum for single ionization of atoms in the tunnelling regime

Abstract

We present results of high-resolution experiments on single ionization of He, Ne and Ar by ultra-short (25 fs, 6 fs) 795 nm laser pulses at intensities 0.15 -2.0. 10 15 W/cm 2 . We show that the ATI-like pattern can survive deep in the tunneling regime and that the atomic structure plays an important role in the formation of the low-energy photoelectron spectra even at high intensities. The absence of ponderomotive shifts, the splitting of the peaks and their degeneration for few-cycle pulses indicate that the observed structures originate from a resonant process.

Coulomb-corrected quantum interference in above-threshold ionization: Working towards multitrajectory electron holography

“…Since the mid-2000s, however, many features stemming from the interplay between the residual binding potential and the laser field have been identified in experiments. Examples are (i) the low-energy enhancements in above-threshold ionization (ATI) spectra [2][3][4][5][6][7][8][9][10][11][12], (ii) the fan-shaped structure in angular resolved ATI electron momentum distributions [13][14][15], and (iii) the species dependency in nonsequential double ionization (NSDI) with circularly polarized fields [16].…”

Photoelectron spectra and high Rydberg states of lithium generated by intense lasers in the over-the-barrier ionization regime

“…In the past two decades, strong-field ionization of atomic targets has been studied widely both in theoretical calculations and in experiments [1][2][3][4][5][6][7][8][9]. Most of the experiments have focused on rare-gas atoms whose ionization potential I p = 12-25 eV, with the laser wavelength centered around 800 nm.…”

Precision calculation of above-threshold multiphoton ionization in intense short-wavelength laser fields: The momentum-space approach and time-dependent generalized pseudospectral method

“…Extensive investigations have been performed both theoretically [11][12][13][14][15][16][17][18] and experimentally [7,12,14,[19][20][21][22][23][24][25][26][27][28][29][30][31] for a comprehensive understanding of the laser-induced atomic ATI for laser fields with wavelengths from visible lights (4×10 2 nm) to infrared radiations (1×10 5 nm). With the recent development of intense and ultrashort-wavelength free-electron lasers [32][33][34], the study of multiphoton * zyzhou@ku.edu † sichu@ku.edu processes in the high-frequency and strong-field regime becomes increasingly important [35][36][37].…”