ABSTRACT
We have developed a two-step " R-transfer" method that efficiently produces translationally ultracold potassium molecules in the X (1)Sigma(+)(g) electronic ground state. Laser-cooled atoms are initially photoassociated at large internuclear separation R to form molecules in high vibrational levels of the 1 (1)Pi(g) state, which are in turn excited by an additional laser to shorter-range Rydberg states such as 5 (1)Pi(u) and 6 (1)Pi(u). Subsequent radiative decay produces ground-state molecules at rates up to 10(5) molecules/second per vibrational level.
ABSTRACT
The new spectroscopic technique of photoassociation of ultracold atoms is reviewed, with an emphasis on connecting this area to traditional bound-state molecular spectroscopy. In particular, in contrast to photoassociative spectra at thermal energies, which are broad and of low information content, photoassociative spectra of ultracold atoms are high resolution, permitting observation of small vibrational and rotational spacings of long-range molecular levels near dissociation (typically with outer classical turning points >20 Å). The types of detection and theoretical analysis employed are illustrated, primarily using the example of 39K2. Future directions and applications of this field (e.g., to ultracold molecular formation) are also discussed. Copyright 1999 Academic Press.
ABSTRACT
Laser frequency-modulated (FM) spectroscopy has been used as an axial probe of a laser-guided electric discharge in sodium-argon vapor contained in an optically accessible metal heat pipe oven. Absorption measurements in the region 23 106-23 881 cm-1 provided accurate line positions (±<0.006 cm-1) for 141 transitions in the v' = 3-8 <-- v" = 0 and v' = 5-9 <-- v" = 1 bands of NaH (A1Sigma+-X1Sigma+). In addition, 18 transitions of Na (3p to 9-13d and 11-14s) and 10 of argon (5p-4s) were measured. Analysis of the spectrum indicates that perhaps all absorption signals are due to neutrals NaH, Na, and Ar and are observed via "population" modulation. Copyright 1997 Academic Press. Copyright 1997Academic Press