Related papers: Resonance Laser Ionization Spectroscopy of Seleniu…
We report on the all-optical detection of Rydberg states in a effusive atomic beam of strontium atoms using electromagnetically induced transparency (EIT). Using narrow-linewidth CW lasers we obtain an EIT linewidth of 5 MHz. To illustrate…
A frequency-stable, broadband laser is presented for experiments on trapped ions. Since the design is based on widely available semiconductor optical amplifier technology, similar lasers can be realized for virtually any wavelength in the…
We have developed a simple analytical model describing multi-atom signals that are measured in experiments on dipole-dipole interaction at resonant collisions of a few Rydberg atoms. It has been shown that finite efficiency of the selective…
Rydberg atom electrometry offers traceable electric field measurements over many decades of radio frequencies in a single device. Miniaturization of these sensors is primarily limited by requirements of the lasers used. Here we demonstrate…
Tunnel ionization rates of triplet Rydberg states in helium with principal quantum numbers close to 37 have been measured in electric fields at the classical ionization threshold of $\sim197$ V/cm. The measurements were performed in the…
Photoelectron angular distributions (PADs) obtained from ionization of potassium atoms using moderately intense femtosecond IR fields ($\sim$10$^{12}$Wcm$^{-2}$) of various polarization states are shown to provide a route to "complete"…
Collinear laser spectroscopy has been performed on He-like C$^{4+}$ ions extracted from an electron beam ion source (EBIS). In order to determine the transition frequency with the highest-possible accuracy, the lineshape of the fluorescence…
Optical systems capable of generating fields with sub-wavelength spatial features have become standard in science and engineering research and industry. Pertinent examples include atom- and ion-based quantum computers and optical…
We present combined measurements of the spatially-resolved optical spectrum and the total excited-atom number in an ultracold gas of three-level atoms under electromagnetically induced transparency conditions involving high-lying Rydberg…
Molecular helium represents a benchmark system for testing $\textit{ab initio}$ calculations on few-electron molecules. We report on the determination of the adiabatic ionization energy of the $a\,^3\Sigma_u^+$ state of He$_2$,…
We study the role of Penning ionization on the photoassociation spectra of He(^3S)-He(^3S). The experimental setup is discussed and experimental results for different intensities of the probe laser are shown. For modelling the experimental…
We present a recently established setup for laser spectroscopy at CRYRING@ESR at the GSI Helmholtz Centre for Heavy Ion Research. Here, laser spectroscopy can be performed on stored and cooled ion bunches and coasting beams. First spectra…
Relative cross sections for the valence shell photoionisation (PI) of $\rm ^2S$ ground level and $\rm ^2D$ metastable Ca$^{+}$ ions were measured with high energy resolution by using the ion-photon merged-beams technique at the Advanced…
We have developed a neutron imaging sensor based on an INTPIX4-SOI pixelated silicon device. Neutron irradiation tests are performed at several neutron facilities to investigate sensor's responses for neutrons. Detection efficiency is…
We demonstrate a velocity selection scheme that mitigates suppression of electromagnetically induced transparency (EIT) by Doppler shifts for low--high EIT probe--coupling wavelength ordering. An optical pumping beam counter-propagating…
The present work explores quantitative limits to the Single-Active Electron (SAE) approximation, often used to deal with strong-field ionization and subsequent attosecond dynamics. Using a time-dependent multi\-configuration approach,…
Unique spectroscopic possibilities open up if a laser beam interacts with relativistic lithium-like ions stored in the heavy ion ring accelerator SIS300 at the future Facility for Antiproton and Ion Research FAIR in Darmstadt, Germany. At a…
We describe laser systems for photoionization, Doppler cooling and quantum state manipulation of beryllium ions. For photoionization of neutral beryllium, we have developed a continuous-wave 235 nm source obtained by two stages of frequency…
The optical cycle-averaged ionization rate of Ar, O$_{2}$, and N$_{2}$ vs. local instantaneous laser intensity $I$ for linear polarized $800$ nm light is determined up to approx. $300$ TW/cm$^{2}$ by numerically inverting published…
We study resonant two-photon ionization of helium atoms via the $1s3p$, $1s4p$ and $1s5p^1$P$_1$ states using the 15$^\mathrm{th}$ harmonic of a titanium-sapphire laser for the excitation and a weak fraction of the laser field for the…