摘要： Infrared lasers at 1 μm are widely used in numerous industrial or medical applications, optical communication and spectroscopy. The lasers available nowadays are based on different laser active media, among which most common used are Nd:YAG, Yb:YAG, Nd:YVO4, or Nd:GdVO4, to mention few of them [1]. In addition, visible laser sources are obtained by using the infrared laser emission in conjunction with highly efficient nonlinear crystals. Furthermore, if the nonlinear crystal is doped with Nd3+ ions, then a compact, more efficient and lower-cost self-frequency conversion laser system could be realized. Thus, the research for finding new laser crystals or nonlinear crystals with prominent self-frequency doubling properties is of great interest in present, owing mostly to the need for up-scaling the existing laser systems. In this work we present our new findings with respect to Nd lasing at 1 μm, when it is inserted in LaGdSc(BO3)4 (LGSB) nonlinear matrix. The LGSB crystal doped with 5 at.% Nd3+ was grown by Czochralski pulling technique in our laboratory, the growth process being similar with that reported by Gheorghe et al. [2]. Worthy to be mentioned, the lasing in Czochralski-grown LGSB crystals was reported previously only for Yb trivalent ions [3]. First, the spectroscopic properties were determined for this laser medium. Thus, the negative uniaxial Nd:LGSB medium presents polarization selective absorption cross sections. Values of 5×10-20 cm2 (σ polarization) and 1.3×10-20 cm2 (π polarization) where measured for the absorption cross section at 807 nm. The determined emission cross sections were ~1.9×10-19 cm2 (π) and ~2×10-19 cm2 (σ). Laser experiments have been performed for two 5.0 at.% Nd:LGSB uncoated crystals: Nd:LGSB-1, length of 6.1 mm, c-cut and Nd:LGSB-2, 3.0-mm thickness, a-cut. The pump was done with a fiber-coupled diode laser (fiber with 100-μm diameter, NA= 0.22) in quasi-continuous wave (quasi-CW) mode (1-ms pump pulse at 10-Hz repetition rate), as well as in CW regime. A linear, 10-mm long plane-plane resonator was used in the experiments and various sizes of the pump-beam were considered. The laser pulse energy, Ep at 1062 nm yielded by Nd:LGSB-1 is shown in Fig. 1a) at a pump-beam diameter of 230 μm. Operation with high slope efficiency, ηsa= 0.67 was obtained; a maximum pulse energy Ep= 13.5 mJ was recorded for absorbed pump-pulse energy of 20.5 mJ (99% absorption efficiency, ηa). The power outputted from the same crystal, in CW operation, amounted to Pout= 1.3 W for Pabs= 2.1 W absorbed pump power; the slope efficiency was ηsa= 0.67 [Fig. 1b)]. The Nd:LGSB-2 crystal showed also a high ηsa= 0.63 slope; the CW power reached Pout= 0.75 W for Pabs= 1.6 W (absorption ηa= 0.74). Results on the polarization status, the laser beam transverse distribution and the influence of the pump-beam dimensions on the laser performances will be presented. These are the first results obtained from diode-pumped Nd:LGSB, showing very good performances at 1062 nm although uncoated laser crystals were employed in the present experiments.