Absorption spectrum and optical parameters of Nd-doped barium sodium niobate crystals

Nd-doped barium sodium niobate, (Ba2Na)(1-x)NdxNb5O15 (Nd:BNN), crystallize s with x = 0.025 in a tetragonal system with a filled tungsten bronze struc ture and the point group 4mm, conforming to the space group P4bm and z = 2. The Curie temperature was 537 +/- 2 degreesC. The lattice constants were a = b = 1.2446(1) and c = 0.3991(1)nm at room temperature. The measured abso rption of Nd:BNN was compared to the Judd-Ofelt (JO) theory. When applied, the JO theory of parity-forbidden electric-dipole transitions of rare-earth ions on non-centrosymmetric sites demonstrates good agreement. An absorpti on band around 808 nm to match laser diode pumping is about three times bro ader than that of. Nd-doped yttrium aluminum garnet crystal. The three inte nsity parameters Omega (t) were fitted as 5.677 x 10(-20), 2.231 x 10(20), and 4.106 x 10(-20)cm(2) at t = 2, 4 and 6, respectively. The fluorescence branch ratio at 1060nm is 52.38%. The largest integrated emission cross sec tion Sigma(F-4(3/2) --> I-4(11/2)) is 10.36 x 10(-18) cm. These results ind icate the crystal's potential applications as a practical laser material.