Lines in the (0, 0) bands of the A2Π-X2Σ+ and B2Σ+-X2Σ+ systems of CaCl and the B2Σ+-X2Σ+ system of SrF have been studied at sub-Doppler resolution by intermodulation spectroscopy. The linewidth was typically 40 MHz (f.w.h.m.). The 19F hyperfine splitting was resolved in the SrF spectrum and was measured for several rotational lines. The measurements were used in conjunction with the hyperfine parameters for the molecule in the ground state (measured by e.s.r.) to determine the following parameters for the B2Σ+ state: b = 12.9 ± 1.6 MHz c = -51 ± 28 MHz. These results suggest that the molecule is ionic, Sr+F-, in the B state. It has not proved possible to resolve 35Cl or 37Cl hyperfine structure in any of the lines studied in either the A-X or the B-X transitions of CaCl. There are pronounced crossover signals in the A-X system which have a negative sign (i.e., opposite to the normal Lamb dip signal). The dependence of these signals on various experimental parameters has been investigated. A density matrix description of the three-level system is presented and solved to 4th order by an iterative method. To this order, the model predicts that the Lamb dip and crossover signals should have the same sign.
ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry