Abstract
We have investigated the excitation of uv and visible fluorescences in La: and La: pumped through the and bands of the impurity ion. We have also investigated the pumping bands in absorption. Several Stark components of the bands of and of in La have been identified. We report uv and visible emissions originating from the state of the ion at 2500, 2700, and 4000 Å and a broad-band fluorescence (2700-4500 Å) in with bandwidth dependent on doping. Using the Judd-Ofelt theory we have calculated the line strengths and transition probabilities for the emissions, obtaining a lifetime for that state of 3.6 μsec. Measurement of the lifetime yielded a value of 720 nsec. The lifetime for the cerium emissions was found to be 20 nsec. The threshold for stimulated emission in the transitions of La: has been calculated and the possibility of uv lasing is discussed.
- Received 18 June 1973
DOI:https://doi.org/10.1103/PhysRevB.8.4989
©1973 American Physical Society