Spectroscopic and luminescent properties of Yb,Er:LaSc3(BO3)4 crystals

Absorption and luminescence spectra and luminescence kinetics of Yb have been measured in crystals of Yb,Er:LaSc3(BO3)(4) (LSB) for a wide region of variation of activator concentration. It has been established that an effective absorption cross-section of Yb3+ at the maximum of 982 nm is equal to 1.16 x 10(-20) cm(2). Effective absorption and emission cross-sections of Er3+ at generation wavelength of 1555 nm are equal to sigma(ab) = 4.4 x 10(-21) and sigma(em) = 5.2 x 10(-21) cm(-2),respectively. F-2(5/2) Yb3+ --> I-4(11/2) Er3+ energy transfer for dominating luminescence centers in Yb,Er:LSB is described satisfactorily by a dipole-dipole interaction with C-DA = 4.16 x 10(-39) cm(-6). Yb-Yb energy migration is very efficient and described by a hopping mechanism with C-DD = 3.5 x 10(-38) cm(-6), the quantum efficiency in Yb-0.15 (6.7 x 10(20) cm(-3)) Er-0.015 (6.7 x 10(19) cm(-3)):LSB crystals has achieved 98%. Investigations of Yb,Er:LSB crystals have shown them to have necessary combination of properties to get an effective generation of 1.5 mu m eye-safe radiation with laser diode pumping. (C) 2000 Published by Elsevier Science B.V. All rights reserved.