We have investigated the correlated momentum distribution of both electrons from nonsequential double ionization of helium in a 800 nm, $4.5\times {10}^{14}\mathrm{W}/{\mathrm{cm}}^2$ laser field. Using very high resolution coincidence techniques, we find a so-far unobserved fingerlike structure in the correlated electron momentum distribution. The structure can be interpreted as a signature of the microscopic dynamics in the recollision process. We identify features corresponding to the binary and recoil lobe in field-free ($e,2e$) collisions. This interpretation is supported by analyzing ab initio solutions of a fully correlated three-dimensional helium model.

We study the control of dissociation of the hydrogen molecular ion and its isotopes exposed to two ultrashort laser pulses by solving the time-dependent Schrödinger equation. While the first ultraviolet pulse is used to excite the electron wave packet on the dissociative $2p{\sigma }_u$ state, a second time-delayed near-infrared pulse steers the electron between the nuclei. Our results show that by adjusting the time delay between the pulses and the carrier-envelope phase of the near-infrared pulse, a high degree of control over the electron localization on one of the dissociating nuclei can be achieved (in about 85% of all fragmentation events). The results demonstrate that current (sub-)femtosecond technology can provide a control over both electron excitation and localization in the fragmentation of molecules.

We present ab initio computations of the ionization of two-electron atoms by short pulses of intense linearly polarized Ti:sapphire laser radiation beyond the one-dimensional approximation. In the model the electron correlation is included in its full dimensionality, while the center-of-mass motion is restricted along the polarization axis. Our results exhibit a rich double ionization quantum dynamics in the direction transversal to the field polarization, which is neglected in the previous models based on the one-dimensional approximation.

We study the suppression of reflections in the numerical simulation of the time-dependent Schrödinger equation for strong-field problems on a grid using exterior complex scaling (ECS) as an absorbing boundary condition. It is shown that the ECS method can be applied in both the length and the velocity gauge as long as appropriate approximations are applied in the ECS transformation of the electron-field coupling. It is found that the ECS method improves the suppression of reflection as compared to the conventional masking function technique in typical simulations of atoms exposed to an intense laser pulse. Finally, we demonstrate the advantage of the ECS technique to avoid unphysical artifacts in the evaluation of high harmonic spectra.

The strength of the $E_{\mathrm{c}.\mathrm{m}.}=184\mathrm{keV}$ resonance in the ${}^{26g}\mathrm{Al}(p,\gamma ){}^{27}\mathrm{Si}$ reaction has been measured in inverse kinematics using the DRAGON recoil separator at TRIUMF’s ISAC facility. We measure a value of $\omega \gamma =35\pm 7\mu \mathrm{eV}$ and a resonance energy of $E_{\mathrm{c}.\mathrm{m}.}=184\pm 1\mathrm{keV}$, consistent with $p$-wave proton capture into the 7652(3) keV state in ${}^{27}\mathrm{Si}$, and discuss the implications of these values for ${}^{26g}\mathrm{Al}$ nucleosynthesis in typical oxygen-neon white-dwarf novae.

Non-Melanoma skin cancer is one of the most frequent types of cancer. Early detection is encouraged so as to ensure the best treatment, Hyperspectral imaging is a promising technique for non-invasive inspection of skin lesions, however, the optimal wavelengths for these purposes are yet to be conclusively determined. A visible-near infrared hyperspectral camera with an ad-hoc built platform was used for image acquisition in the present study. Robust statistical techniques were used to conclude an optimal range between 573.45 and 779.88 nm to distinguish between healthy and non-healthy skin. Wavelengths between 429.16 and 520.17 nm were additionally found to be optimal for the differentiation between cancer types.