The efficient production of very-high-
n, $n\ensuremath{\sim}300$, quasi-one-dimensional (quasi-1D) strontium Rydberg atoms through three-photon excitation of extreme Stark states in the presence of a weak dc field is demonstrated using a crossed laser-atom beam geometry. Strongly polarized quasi-1D states with large permanent dipole moments $\ensuremath{\sim}1.2{n}^{2}$ a.u. can be created in the beam at densities ($\ensuremath{\sim}{10}^{6}$ cm${}^{\ensuremath{-}3}$) where dipole blockade effects should become important. A further advantage of three-photon excitation is that the product
F states are sensitive to the presence of external fields, allowing stray fields to be reduced to very small values. The experimental data are analyzed using quantum calculations based on a two-active-electron model together with classical trajectory Monte Carlo simulations. These allow determination of the atomic dipole moments and confirm that stray fields can be reduced to $\ensuremath{\le}25\phantom{\rule{4pt}{0ex}}\ensuremath{\mu}$V cm${}^{\ensuremath{-}1}$.
The production of high-
n, $n\ensuremath{\sim}300$, quasi-one-dimensional (quasi-1D) strontium Rydberg atoms through two-photon excitation of selected extreme Stark states in the presence of a weak dc field is examined using a crossed laser-atom beam geometry. The dipolar polarization of the electron wave function in the product states is probed using two independent techniques. The experimental data are analyzed with a classical trajectory Monte Carlo simulation employing initial ensembles that are obtained with the aid of quantum calculations based on a two-active-electron model. Comparisons between theory and experiment highlight different characteristics of the product quasi-1D states, in particular, their large permanent dipole moments, $\ensuremath{\sim}
1.0to1.2{n}^{2}e{a}_{0}$, where
e is the electronic charge and
a0 is the Bohr radius. Such states can be engineered using pulsed electric fields to create a wide variety of target states.
Very-high-n (n~300) Rydberg atoms serve as a powerful tool to study chaos and quantum optical phenomena. Measurements using a series of alternating impulsive kicks applied to potassium Rydberg atoms reveal that a phase space geometric structure called the turnstile governs the ionization process. Studies of the excitation spectra for potassium Rydberg atoms in a strong sinusoidal electric drive field in the radio frequency (100-300 MHz) regime, display quantum optical phenomena including electromagnetically induced transparency and Aulter-Townes splitting, and the data are well explained within the framework of Floquet theory. In order to study the strong dipole-dipole interactions between neutral atoms, new experimental techniques have been developed to create high densities of very-high-n (n~300-500) strontium Rydberg atoms using two- and three-photon excitation. The data demonstrate that high densities of strongly-polarized quasi-one-dimensional states can be produced and form the basis for further manipulation of the atomic wave functions. The strontium Rydberg states are modeled using a two-active-electron theory which produces results in good agreement with experimental observations.