Abstract

High-resolution measurements of molecular structure very near a dissociation limit can be used both to probe long-range atomic interactions and to make accurate determinations of dissociation energies. Our research group has investigated the H(1s) + H(2s or 2p) dissociation limit in molecular hydrogen using optical double resonance with single-mode lasers. Fig. 1 shows the general scheme of the experiment. Our measurements of bound states in H₂, reported in Ref. ¹, have now been extended to include the adjoining continuum and the other stable isotopomers, HD and D₂. The most weakly bound levels to which transitions are seen are bound by only about 0.03 cm⁻¹, equivalent to about 40 mK. Very sharp continuum resonances are also observed in the region just above threshold.

© 1993 Optical Society of America