Use of a LiF colour centre laser for pumping an Yb:YAG active medium

Broadband collimated generation in YAG:Yb crystal and ytterbium glass under LiF:F+2color center laser pumping

“…The shape of 20-30 ns ccl pulses was similar to the ruby laser pulses. The ccl radiation spectrum with a smooth envelope occupied the region from 0.89 to 0.95 µm with the maximum near λ p = 0.92 µm [3]. Due to a little time needed for the ccl generation build up and its large spectrum width one can speak about a low coherence of the ccl radiation.…”

Surface damage of YAG crystal induced by broadband nanosecond laser pulses: morphology of craters and material deformation

“…In contrast to YAG crystal, the Yb:YAG sample revealed several craters with obvious signs of melting: the microphotographs (figures 2(a) and (b)) show the damage zones with melted surface, cracks and drops of melted material outside the crater. The absorption coefficient of CCL radiation in the Yb:YAG plate near λ ≈ 0.9 µm is ≈20 cm −1 [10]. At pumping the Yb:YAG crystal from the ground level 2 F 7/2 of Yb 3+ ions to the 2 F 5/2 metastable level, about 10%of the pump energy transforms in heat via non-radiative transitions between Stark components of the levels [17].…”

“…The laser damage thresholds and damage mechanisms in these materials, which limit the laser output power, were studied for the case of short laser pulses in publications [5][6][7][8][9]. In our previous experiments with YAG crystals [10][11][12][13][14][15][16], a color-center LiF: + F 2 laser (CCL) was used as a source of low-coherence intensive radiation. Single pulses of CCL broadband (≈500 Å) radiation (20-30 ns pulse duration, energy up to 100 mJ, the spectral range 0.89-0.95 µm with the maximum at the wavelength λ ≈ 0.91 µm) were focused onto the surfaces of YAG, Yb:YAG, quartz and other materials into a spot of 100-300 µm in diameter.…”

Excitation of Periodical Shock Waves in Solid–State Optical Media (Yb:YAG, Glass) at SBS of Focused Low–Coherent Pump Radiation: Structure Changes, Features of Lasing

“…Cr:LiSAF, Ti:Sa, Nd:YAG (0.94 µm transition) lasers have been used to pump Yb:S-FAP and Yb:YAG (Bykovsky et al, 2000;Kanabe et al, 2000;Marshall et al, 1997, as cited in Bykovsky & Senatsky, 2008b. In our work a LiF: F 2 + color center laser (ccl) was used to pump an Yb:YAG crystal (Basiev et al, 2004). The lithium fluorine color center (LiF: F 2 + , LiF: F 2 -) lasers are the sources of radiation in the near IR (0.8-1.3 µm) , and they effectively convert the neodymium and ruby laser radiation into this spectral range (Basiev et al, 1982).…”

“…An experimental study of a small region with high pressure and temperature gradients formed in a medium at focusing high-power laser radiation had been performed, as a rule, outside the laser cavity. In our experiment (Basiev et al, 2004), a region with such properties happened to be formed directly in the 2-mirror laser cavity, when Yb:YAG samples were pumped by the focused wide-band (0,89-0,95 m) radiation from a pulsed LiF: F 2 + color center laser (ccl). Thus, in contrast to many studies on ytterbium lasers, conditions for generation in Yb-doped samples in this experiment had been distinguished by the very high intensity (over 1 GW/cm 2 ) of the pump, which moreover had a low coherence.…”