Comparison of neodymium-doped LaSc3(BO3)4 and CdVO4 crystals under diode laser pumping

Abstract

Microchip lasers require a laser medium with high absorption and slope efficiency and a low threshold. From this point of view the materials of choice might be Nd: LaSc3(BO3)4 (Nd:LSB) and Nd:GdVO4 (Nd:GVO). The main features of these crystals are strong and broad absorption bands near 808 nm, a very high emission cross section at 1.06 μm for GVO, and broad emission line of LSB (Table 1). Under diode pumping 1-1.5 mm long GVO and LSB crystals demonstrate more than 850 mW of output power at 1.06 μm with a slope efficiency close to 60%.1,2 In order to achieve the same results with Nd:YAG it is necessary to use a 5-8 mm-long crystal. On the other hand both LSB and GVO suffer more from the thermal problems than YAG and require re-adjustment to compensate the thermal lens in order to maintain a good beam profile.