Bifunctional Bi2ZnOB2O6:Nd3+ Single Crystal for Near Infrared Lasers: Luminescence and μ-Raman Investigations

Bi2ZnOB2O6 single crystal doped with Nd3+ ions is characterized by high values of nonlinear optical coefficients as well as the effective luminescence of excited Nd3+ ions, which make this system a unique candidate for near infrared to visible laser converters. The investigated Bi2ZnOB2O6:Nd3+ single crystal was grown by means of the Kyropoulos method. The vibrational properties of Bi2ZnOB2O6:Nd3+ were studied using mu-Raman spectroscopy. In particular, the Raman-active modes detected in parallel and cross-polarizations were assigned to the vibrations of the characteristic molecular groups BO3, BO4, ZnO4, and BiO6. In the absorption spectra of Bi2ZnOB2O6:Nd3+ the bands related to the optical transitions from the I-4(9/2) ground state to the excited states of Nd3+ ions were detected at 432, 515, 528, 533, 577, 586, 689, 750, 810, 874, and 1605 nm. Moreover, the strong emission of Bi2ZnOB2O6:Nd3+ with a maximum at about 1062 nm (F-4(3/2) -> I-4(11/2) transition) was detected under the excitation at 514 nm. The decay kinetics profile monitored for the F-4(3/2) -> I-4(11/2) transition of Nd3+ ions shows a relatively long fluorescence lifetime equal to 109 mu s, which allows efficient emission from the F-4(3/2) level of Nd3+ ions. Because of the good spectroscopic properties of the investigated system as well as nonlinear optical properties of the host, the Bi2ZnOB2O6:Nd3+ single crystal can be efficiently used as the self-frequency doubling lasers.