Anisotropy of optical absorption intensity in Tm3+ doped YVO4 crystals

Seven absorption group-bands (D-1(2), (1)G(4), F-3(2), F-3(3), H-3(4), H-3( 5), F-3(4)) Of Tm3+ in YVO4 single crystals have been observed in the orien tation absorption spectra recorded in the spectral range from 200 to 4000 n m at 300K. The integrated absorption cross section for each group-band was accurately evaluated. On the assumption that the anisotropy of this uni-axi al crystal is small, the Judd-Ofelt theory was extended for the calculation of 4f-4f transition intensities of Tm3+ in YVO4. Two sets of phenomenologi cal intensity parameters were derived from a least-squares-fit procedure. For c-axis cut sample we have Ohm(2) = 10.18 (10(-20)cm(2)), Ohm(4) = 1.96 (10(-20)cm(2)), Ohm(6) = 0.75 (10(-20)cm(2)). For a-axis cut sample we have Ohm(2) = 8.20 (10(-20)cm(2)), Ohm(4) = 2.47 (10(-20)cm(2)), Ohm(6) = 0.91 ( 10(-20)cm(2)). The anisotropy of the optical absorption intensities of Tm3+:YVO4 was theor etically analyzed in detail.