Yb^3+-doped ceramic thin-disk lasers of Lu-based oxides

Comparative study of Yb:Lu3Al5O12 and Yb:Lu2O3 laser ceramics produced from laser-ablated nanopowders

“…Let us discuss the reasons for the thermal roll-over observed for the Yb:Lu2O3 ceramic laser. The thermal conductivity of Yb:Lu2O3 ceramics is high (κ = 13.9 Wm -1 K -1 for 3 at.% Yb doping [10]) and is weakly dependent on the Yb doping level [45]; moreover, it is higher than that for Yb:Lu3Al5O12 [10]. This difference would compensate for the higher fractional heat load in Yb:Lu2O3 originating from the longer emission wavelength.…”

“…Pirri et al demonstrated a highly-doped 10 at.% Yb:Lu3Al5O12 ceramic laser diode-pumped at 936 nm delivering 6.0 W at 1030 nm with a slightly higher slope efficiency of 52% [25]. Yb:Lu3Al5O12 ceramic thin-disk lasers are also known: Nakao et al developed such a thin-disk laser with an output power of 166 W and a slope efficiency of 72.2% [10].…”

Sintering of transparent Yb-doped Lu 2 O 3 ceramics using nanopowder produced by laser ablation method

“…Laser quality Yb-doped Lu 2 O 3 ceramics were successfully fabricated by nanocrystalline powder technology and vacuum sintering [19,20] or combination of hot pressing and hot isostatic pressing [21]. Currently, however, the maximum output power and efficiency of Yb somewhat inferior than that of the single crystal.…”

Diode-side-pumped, passively Q-switched Yb:LuAG laser

“…in comparison to Nd laser media [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Their main deficiencies, resulting from a quasi-three-level scheme, can be overcome via cryogenic operation [4,5,8,10] or by applying special architectures such as thin disks [6,13,16], slabs [7][8][9][10][11] or fibers [12]. Excluding a few cases [9,10], the end-pumping scheme has dominated high-power Yb laser systems because of the specific requirements of quasi-III-level media and the relative simplicity and compactness of beam-shaping optics currently available for high-power laser diode stacks.…”

“…However, compared to Nd gain media, the saturation fluency in Yb-doped media is significantly larger (for instance, it is as high as 10 J/cm 2 for Yb:YAG); this poses a risk of damage to the laser elements inside the cavity. Therefore, we have chosen as a gain medium the relatively novel Yb:LuAG crystal [13][14][15][16], which has comparable thermo-optical and mechanical parameters as Yb:YAG but about 25% higher gain cross-section,s em ¼ 2.5 Â 10 À 20 cm 2 . We present an analysis that aims to decrease the gain in such a laser system concurrently with efficient energy extraction.…”