Abstract
The two-photon transition from the ground state to the lowest state in :Ca has been studied with a tunable dye laser as a function of laser wavelength, intensity, polarization, and focusing geometry. At liquid-helium temperatures, a no-phonon resonance line is observed and is accompanied by its vibrational sideband. The peak cross section for the two-photon absorption is of order 5× sec, indicating significant crystal-field parity mixing for the levels. The nophonon line shows a polarization anisotropy consistent with a site of symmetry. The phonon sideband has a frequency-dependent polarization anisotropy.
- Received 8 June 1983
DOI:https://doi.org/10.1103/PhysRevB.28.3706
©1983 American Physical Society