Laser action in neodymium-doped zinc chloride borophosphate glasses

Laser action has been predicted in neodymium-doped zinc chloride borophosph ate glasses with the help of laser parameters for the transitions F-4(3 2) --> I-4(9 2), F-4(3 2) --> I-4(3 2) and F-4(3 2) --> I-4(13 2) in the near- IR region. Judd-Ofelt parameters have been used for the calculations of dif ferent laser parameters. Various energy interaction parameters like Slater- Condon, Lande. Racah and bonding parameters have also been calculated. A co mparison with borophosphate glasses shows a considerable increase (by a fac tor of similar to 6) in the value of stimulated emission cross-section, sig ma (p), of the transition F-4(3 2) --> I-4(13 2) when ZnCl2 is added. This increase in sigma (p) is mainly due to increase in the covalency in zinc ch loride borophosphate glasses. The high value of figure-of-merit for gain, s igma (p)tau (R) ( similar to 6.83 x 10 (- 24) cm(2) s), for this transition is comparable with the value reported in the case of Nd3 +-doped fluoroalu minate glasses. This high value is favourable for an efficient 1.3 mum fibr e amplifier. The glass composition (mol.%) is B2O3 (14.57)-P2O5 (44.55)-Na2 O(26.D8)-ZnCl2 (14.50)-Nd2O3 (R) (R = 0.1, 0.2, 0.3 and 0.4 mol.%). This ha s been prepared by the melt quenching technique. (C) 2001 Elsevier Science B.V. All rights reserved.