Themes > Science > Physics > Molecular Physics > Atomic, Molecular and Optical Physics > Atomic and Molecular Spectroscopy

Modern spectroscopy is much more than the passive observation of energy levels. Taking a much more active approach, experimenters manipulate atoms and molecules into novel situations selected to yield clear answers to important physical questions. Spectroscopic studies at UConn take advantage of the extensive laser facilities available in several different laboratories, spanning the spectrum from the infrared to the far ultraviolet, with a variety of bandwidths and powers.

In atomic physics, projects include studies of highly excited (Rydberg) atoms, as well as a collaborative project with NIST to measure the far-UV $1S$-$2S$ interval in atomic helium, a fundamental system that tests the limits of our ability to calculate the effects of quantum electrodynamics in multi-electron systems. Frequency-stabilized diode laser systems have been developed and used for precision two-photon spectroscopy, excited-state atomic collisions, and laser cooling of atoms. Other projects seek to develop new spectroscopic methods that take full advantage of improved technology and ideas.

The study of molecules and interatomic interactions is a particular emphasis at UConn. Current projects include laser spectroscopy and photodynamics of diatomic molecules, photoassociative spectroscopy, laser ionization spectroscopy and laser produced plasmas, optically pumped molecular lasers, studies of transition state dynamics and cluster dynamics, precision measurements in small molecules, and investigations of molecular behavior in very highly excited vibrational and electronic states.

Recent accomplishments include measurements of some of the highest vibrational levels in various states of both alkali dimers and molecular hydrogen. This information complements theoretical and experimental studies of long-range atomic interactions and photoassociation spectroscopy in traps, completing our picture of the interaction process all the way from atomic separations of a single Bohr radius to many thousands of atomic diameters. Ionization potentials and dissociation energies of basic molecular systems have been determined at UConn with unprecedented accuracy. Investigations are underway of optically pumped diatomic lasers and of neutral and ionized excimer lasers, as well as the underlying basic physics of dissociative recombination (for example, Na${}_3^+$ + e${}^{\hbox{-}}$ $\rightarrow$ Na${}_2^*$ + Na) and its inverse, associative ionization (Na${}_2^*$ + Na $\rightarrow$ Na${}_3^+$ + e${}^{\hbox{-}}$).

One of the newest efforts is an investigation of coherent optical interference in molecules and of the prospects for ``coherent control'' of photodissociation. Another new initiative is a coordinated effort to cool and trap molecules, already described on this page .


Information provided by: http://www.phys.uconn.edu