STARK SPLITTING SCHEME AND AN INDUCED EMISSION CROSS-SECTION OF TBALO3

Detailed absorption and emission spectra on TbAlO3 are measured at roo m temperature and liquid-nitrogen temperature. By decomposition of the spectra, the Stark splitting scheme is established for F-7(6), F-7(5) and D-5(4) multiplets of Tb3+ ions in TbAlO3 together with the peak e nergies in the Fourier transform infrared spectrum at liquid-nitrogen temperature. The multiplets are split into their maximum number of lev els, which shows that the point symmetry is low for the Tb3+ ion site in TbAlO3. An induced emission cross section is estimated using the re sults of decomposition at liquid-nitrogen temperature to be 3.55 x 10( -19) cm(2). This value is comparable to the cross sections reported fo r Nd:Y3Al5O12, which is a well known solid-state laser material. The p opulation inversion threshold is also estimated for TbAlO3 in comparis on with Nd:Y3Al5O12 It is found that the threshold value for TbAlO3 is only about three times larger than that for Nd:Y3Al5O12. This TbAlO3 may have the potential to be a laser material with a visible wavelengt h at least at low temperature. (C) 1998 American Institute of Physics.