Atomic Coherence and its Spectroscopic Applications

P. R. Berman

The manner in which laser spectroscopic techniques can be use to probe collisional processes in atomic vapors is reviewed, A discussion of the saturation spectroscopy of three-level Systems, coherent transient spectroscopy, and a beam-laser spectroscopy System is presented. It is shown that such experiments can provide useful information on both the total and differential cross sections for atom-atom scattering.

Alfred Kastler

Zoe‐Elizabeth Sariyanni

In the present quantum optics and laser physics study, the non-linear interaction\nof electromagnetic fields with atomic, molecular and biomolecular media is analyzed.\nParticular emphasis is given to coherent phenomena, while propagation and dispersion\neffects are also extensively investigated. The fields involved vary from ultra short\npulses to continuous waves; while their energies range from the very strong that are\naddressed classically, to the very weak which are described quantum mechanically.\nApplications and problems addressed span a wide range. A scheme for a real time\ndetector of chemical and biological hazards, like anthrax spores, is presented; in it,\na strong spectroscopic signature is obtained from complex molecules by using ultrashort,\nfemtosecond, laser pulses and inducing vibrational coherence on them. Furthermore,\na way of reversing the phase matching condition in coherent spectroscopy,\nbased on dispersion, is developed; which allows for the use of such spectroscopic methods\nin remote detection. More fundamental questions addressed include a resolution\nof the centennial old paradox of Maxwell's demon via quantum thermodynamics, and\nthe role of atomic coherence in enhancing the efficiency of a heat engine as well as\nin obtaining lasing without population inversion. Additionally, a quantum storage\nscheme is presented, in which the information contained in an optical pulse is stored\nand restored via photon echoes.

Dipankar Bhattacharyya, Jyotirmoy Guha

George William Series

Solvejg Jørgensen, Ronnie Kosloff

A spectroscopic application of the atom laser is suggested. The spectroscopy termed 2PACC (two-pulse atomic coherent control) employs the coherent properties of matter waves from a two-pulse atom laser. These waves are employed to control a gas–surface chemical recombination reaction. The method is demonstrated for an Eley–Rideal reaction of a hydrogen or alkali atom-laser pulse where the surface target is an adsorbed hydrogen atom. The reaction yields either a hydrogen or alkali hydride molecule. The desorbed gas-phase molecular yield and its internal state is shown to be controlled by the time and phase delay between two atom-laser pulses. The calculation is based on solving the time-dependent Schrödinger equation in a diabatic framework. The probability of desorption which is the predicted 2PACC signal has been calculated as a function of the pulse parameters.