The 2-photon excitation processes to near-ultraviolet states in Ce-3 plus:CaF2

U Fritzler

Pavel A Apanasevich, R. I. Gintoft, A. G. Makhanek

Swapan Kumar Gayen, Gerald J. Pogatshnik, D. S. Hamilton

The 4f-->5d near-ultraviolet transitions in Ce3+:CaF2 are dipole allowed in one-photon absorption (OPA) and first-order parity-forbidden for two-photon absorption (TPA). A relaxation of the parity selection rule due to odd crystal-field components has previously been observed1 in the TPA from the 4f ground state to the lowest 5d state. In this paper the TPA measurements are extended to include transitions to the higher 5d states.

Swapan Kumar Gayen, D. S. Hamilton

A. G. Makhanek, G. A. Skripko

To study the role of stepwise and relaxation processes under effective excitation of anti-Stokes luminescence of rare-earth (RE) ions in crystals the time-shifted pulse method is used. It is shown that direct comparison of measured single- and two-photon luminescence excitation spectra often enables one to make immediate conclusions on the position and classification of electron levels of RE ions. The Tb3+ and Eu3− level structures (crystal CaF2) in the near ultraviolet are considered as an example. The peculiarities connected with the polarization characteristics of the two-photon absorption of radiation by the trivalent RE ions in a crystal matrix are discussed. To obtain the two-photon spectra a frequency-tunable organic dye solution laser (ODSL) is used.

W. Kaiser, C. G. B. Garrett