Erratum

L.H. Haber, B. Doughty, and S.R. Leone: "Photoelectron velocity map imaging of single–photon and pump–probe ionization of noble gases using femtosecond high–order harmonics," Rev. Mex. Fis. S 56(2) (2010) 85–87.

• The complete 3^rd paragraph of page 85 should read:

"The photoelectron angular distributions of randomly oriented atoms and molecules from single–photon ionization using linearly polarized light is given by where a is the total cross section, θ is the angle between the laser polarization and electron velocity vectors, and β is the anisotropy parameter associated with the second order Legendre polynomial [1]. For atoms, the anisotropy parameter can be described using the equation,

where Δ = δ_l+1 – δ_l–1 [2]. Here, δ_l±1 is the phase shift and D_l±1is the radial dipole matrix element of the partial wave of angular momentum l ± 1. For an electron originally in an atomic orbital of angular momentum l, the outgoing partial waves will have angular momenta of l ± 1 and the interference pattern of these partial waves results in the observed photoelectron angular distributions. The radial dipole matrix elements and the phase shift differences depend on photoelectron energy and provide information on both the bound and continuum wavefunctions. The anisotropy parameters, therefore, provide detailed information on properties of photoionization."

• The first complete paragraph of page 86 should read:

"Inverted images from single–photon ionizations of He, Ne, Ar, and Xe are shown in Figs. 1a–1d. The anisotropy parameter, β, is evaluated at the peak radius for each ring. Using the 17^th harmonic (26.5 eV), the β values of He and Ne are 2.03 ± 0.05 and 0.24 ± 0.01, respectively. Using the 13^th harmonic (20.2 eV), the β values for the ionization of Ar to the ²P_3/2 state and Xe to the ²P_1/2 and ²P_3/2 states are 0.85 ± 0.06, 1.59 ± 0.07, and 1.72 ± 0.04, respectively. For He, there is only one partial wave, the P wave, and the expected β value of 2.00 is in agreement with the measurements. Additional photoelectron images from single photon ionization of Ne, Ar, and Xe were taken with the 11^th and 13^th harmonics. Using the 11^th harmonic (17.1 eV) the β values for the ionizations of Ar to the ²P_3/2 state and Xe to the ²P_1/2 and ²P_3/2states are 0.27 ± 0.05, 1.05 ± 0.10, and 1.45 ± 0.01, respectively. Using the 15^th harmonic (23.4 eV), the β values for the ionization of Ne and Ar are –0.16 ± 0.03 and 1.27 ± 0.01, respectively. All reported anisotropy parameters are in excellent agreement with literature values [7–9]."