Abstract

Using multiphoton-ionization spectroscopy, we have observed transitions from the ¹S₀ ground states to the 4snp, 5snp, and 6snp ³P⁰ states of the alkaline earth atoms Ca, Sr, and Ba, respectively. One-photon transitions from a ¹S₀ ground state to ³P⁰ states are spin-forbidden. We have identified these series in Ca and Sr up to n > 70, whereas previous efforts have failed to identify these series beyond n = 7. These series behave like nearly constant quantum-defect (δ) series with δ_Ca = 1.97 and δ_Sr = 2.90. Preliminary results for Ba, up to n = 60, indicate greater complexity.

© 1977 Optical Society of America

Bound, odd-parity J = 1 spectra of the alkaline earths: Ca, Sr, and Ba

J. A. Armstrong, J. J. Wynne, and P. Esherick
J. Opt. Soc. Am. 69(2) 211-230 (1979)

High-resolution Rydberg-state spectroscopy of stable alkaline-earth elements

R. Beigang
J. Opt. Soc. Am. B 5(12) 2423-2436 (1988)

Spectroscopy of even-parity autoionizing levels in Ba

J. J. Wynne and J. P. Hermann
Opt. Lett. 4(4) 106-108 (1979)

Quantum-defect analysis of the effects of np² terms on the singlet terms of alkaline earths and of their isoelectronic sequences*

K. T. Lu
J. Opt. Soc. Am. 64(5) 706-711 (1974)

Ionization studies in laser-excited alkaline-earth vapors

J. P. Hermann and J. J. Wynne
Opt. Lett. 5(6) 236-238 (1980)