Spectroscopic and laser properties of BeLaAl_(11)O_(19) crystals doped with Cr~(3+) and Nd~(3+) ions

摘要

In this work the opportunity of realization of laser action on vibronic transitions of Cr~(3+) ions in new crystal -hexaaluminate of beryllium-lanthanum (BeLaAl_(11)O_(19):Cr) is investigated. The thermodynamic and physical parameters of host crystal were studied. The experimental spectroscopic and relaxation properties of Cr~(3+) ions have been performed. Absorption and fluorescence spectra are characteristic for octahedral coordinated trivalent ions. The emission cross-section of broadband ~4T_2-~4A_2 transition is determined (～2·10~(-20) CM~2). In configuration curves model the basic features of fluorescence and perspective of lasing in the 700-1000 nm range are considered. The new laser crystals BeLaAl_(11)O_(19):Nd were grown by the Czochralski methods. This material has broad absorption bands at 580, 740 and 790 nm, the latest can be used for LD pumping. The broadest emission lines at 1050 and 1080 nm are perspective for ultrashort laser pulses generation. The intensity parameters, spontaneous emission probabilities, the inter-manifold branching ratios and fluorescent lifetime have been calculated by means of Judd-Ofelt theory and compared with the experiment. The CW generation was realized under Ar-laser pump and laser properties were investigated. The investigation shows that the BeLaAl_(11)O_(19) is a promising host for a creature the new solid state laser media.