Atomic laser

Resonant processes of some importance include resonant electronic to electronic energy transfer (E-E), such as the pumping process of the iodine atom laser... 

Hagley E W, Deng L, Kozuma M, Wen J, Helmerson K, Rolston S L and Phillips W D 1999 A well-collimated quasi-continuous atom laser Sc/ence 283 1706... 

Lett P D, Watts R N, Westbrook C I, Phillips W D, Gould P L and Metcalf H J 1988 Gbservation of atoms, laser-cooled belowthe Doppler limit Phys.Rev.Lett. 61 169-72... 

The spectroscopy of ion lasers is generally less well understood than that of neutral atom lasers because of the lack of detailed knowledge of ion energy-level schemes. Indeed, ion lasers were first produced accidentally and attempts to assign the transitions came later. 

Relatively little work has been done on the flash photolysis of gas phase metal carbonyls, partly because of the low volatility of many of the compounds. Early work by Callear (41,42) provided some evidence for Ni(CO)3 generated from Ni(CO)4 in the gas phase (41) and Fe atoms produced from Fe(CO)5 (42). This latter process has even been used as the basis of an Fe atom laser (43). More recently Breckenridge and Sinai (44) studied the flash photolysis of Cr(CO)6. Their results, interpreted largely on the basis of data from matrix isolation experiments, were in broad agreement with Kelly and Bonneau s solution work (JJ). In particular, they found no evidence for loss of more than one CO group [Eqs. (4) and (5)]. 

Proceedings Bose-Einstein Condensates and Atom Lasers... 

The quenching of iodine atom laser action by Bra,31 which is almost as efficient as I2, is now known to occur via the fast reaction... 

F. R. Prell, Jr.. J. T. McCaffrey. M. D. Seltzer, and R. G. Michel. "Instrumentation for Zeeman Electrothermal Atomizer Laser Excited Atomic Fluorescence Spectrometry,"... 

Feld, M.S. and K. An The Single Atom Laser. Si -ienttfre American. 56-63 (July 1998). 

RELATIVISTIC EFFECTS IN NON-LINEAR ATOM-LASER INTERACTIONS AT ULTRAHIGH INTENSITIES... 

Relativistic effects in non-linear atom-laser interactions at ultrahigh intensities 107... 

Comparison between collisions with the metastable Xe atom, laser-assisted collision and van der Waals excitation has been performed by Richman et al. (1993) on the Xe + BrCCl3 system. Excitation of xenon with BeCCl3 leads to two possible channels formation of XeBr or XeCl. The relative proportion of each product is highly sensitive to the entrance channel and to the experimental conditions, as listed below. 

In the case of the 1S-3S transition in hydrogen and for an estimated velocity of v=3km/s, the shift is Av =l4A kHz. We can t measure the velocity distribution by observing the Doppler broadened 1S-2P transition at 121 nm with a colinear laser beam, because the production of Lyman-a radiation is very difficult. In 1991 a method to compensate or at least to measure this effect was proposed by F. Biraben [7]. The basic idea is to apply a transverse magnetic field B in the atom-laser interaction region. This field has two effects ... 

With the advent of great interest in possible electronic excitation molecular chemical lasers and selective preparation of excited atomic lasers, this entire area of potential surface considerations and, especially, for excited state reactions takes on an even greater significance. The basic concepts and references remain the same. 

Metal atom lasers and eximer lasers for in situ and LIDAR detection... 

Numerical method for modelling atmospheric O2 photodissociation in the wavelength range 175—200 nm Br atom laser action from photodissociation of IBr by solar radiation. Theoretical and experimental study t Cross-section for Ij photodissociation in seeded supersonic beams by CW Ar laser radiation at 514.5 nm... 

D-substituted monochloroethanes Rate constants at 298 K Chain reactions in the Ojf A)- atom laser 193 nm photolysis of I2. Reaction with CF3H, C2F3H, i-C3F7H, CF4, and C2F5... 

For multi-electron systems, it is not feasible, except possibly in the case of helium, to solve the exact atom-laser problem in 3 -dimensional space, where n is the number of electrons. One might consider using time-dependent Hartree Fock (TDHF) or the time-dependent local density approximation to represent the state of the system. These approaches lead to at least njl coupled equations in 3-dimensional space which is much more attractive computationally. For example, in TDHF the wave function for a closed shell system can be approximated by a single Slater determinant of time dependent orbitals,... 

Fig. 3 shows the Raman spectra of the as-deposited and laser irradiated a-C films deposited at 300 V substrate bias. The spectrum for the as-deposited sample can be fitted with a single BWF peak located at 1536.3 cm which corresponds to the presence of about 50% s[ bonded atoms. Laser irradiation with energies higher than 206 mJ/cm results in the formation of sp clusters which is significantly lower compare to the same energy required for sf clustering in high sp bonded films (Fig. 3B). 

Non -ionizing Radiation - Radiation that has insufficient energy to remove electrons from atoms. Laser and Radiofrequency radiation is considered non-ionizing radiation. 

SUB-DOPPUIR COOLING In 1988 the NIST-Gaithersburg group made careful measurements of the temperature of atoms laser cooled in optical molasses, cind found temperatures significantly below the Doppler cooling limit 113). The initial measurements on laser cooled sodium atoms gave temperatures of about 40 pK, about six times lower tham the predicted lower limit of 240 pK. 

Currently, a major theme in atomic, molecular, and optical physics is coherent control of quantum states. This theme is manifested in a number of topics such as atom interferometry, Bose-Einstein condensation and the atom laser, cavity QED, quantum confutation, quantum-state engineering, wavepacket dynamics, and coherent control of chemical reactions. 

There are two typical spectroscopic experiments. In the first, both lasers are in resonance with atomic (laser 1) and molecular (laser 2) transitions and the monochromator (Fig. 2) is scanned to record the laser-induced fluorescence. In the second type of experiment, the monochromator is used as a filter and is not scanned while the second laser wavelength is changed. This second type of experiment is called a laser excitation scan since a fluorescent signal is detected by the PMT only when laser 2 is in resonance with a molecular transition. In this case, the scanning laser can be broadband for survey work or single mode for high-resolution experiments. 

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