Laser action in neodymium-doped zinc chloride borophosphate glasses

Laser action has been predicted in neodymium-doped zinc chloride borophosphate glasses with the help of laser parameters for the transitions 4F3/2→4I9/2, 4F3/2→4I11/2 and 4F3/2→4I13/2 in the near-IR region. Judd–Ofelt parameters have been used for the calculations of different laser parameters. Various energy interaction parameters like Slater–Condon, Landé, Racah and bonding parameters have also been calculated. A comparison with borophosphate glasses shows a considerable increase (by a factor of ∼6) in the value of stimulated emission cross-section, σp, of the transition 4F3/2→4I13/2 when ZnCl2 is added. This increase in σp is mainly due to increase in the covalency in zinc chloride borophosphate glasses. The high value of figure-of-merit for gain, σpτR (∼6.83×10−24 cm2 s), for this transition is comparable with the value reported in the case of Nd3+-doped fluoroaluminate glasses. This high value is favourable for an efficient 1.3 μm fibre amplifier. The glass composition (mol.%) is B2O3 (14.57)–P2O5 (44.85)–Na2O(26.08)–ZnCl2 (14.50)–Nd2O3 (R) (R=0.1, 0.2, 0.3 and 0.4 mol.%). This has been prepared by the melt quenching technique.