Sub-50-fs widely tunable Yb:CaYAlO_4 laser pumped by 400-mW single-mode fiber-coupled laser diode

Abstract

Yb:CaYAlO(4) has been investigated spectroscopically and compared to better known Yb:CaGdAlO(4). It turns out that both materials show very similar spectroscopic parameters relevant to ultrafast lasers design. Employing single-mode fiber-coupled 400-mW laser diode at 976 nm we measured pulses as short as 43 fs, and broad tunability of 40 nm with a simple single-prism setup.

Efficient Yb^3+:CaGdAlO_4 bulk and femtosecond-laser-written waveguide lasers

“…The fluorescence lifetime was determined by the pinhole method [18,19]. For different crystals with doping concentrations between 4.9% and 10%, it did not change significantly and was always in the order of 445 10 μs, comparable to the results in [12].…”

“…1). The peak values in σ-polarization are about 11% higher than the values in [12], and the anisotropy between π-and σ-polarization of 2.7 is somewhat smaller than the value of 3 reported there. It should be noted that only the first deviation may arise from the error in the determination of the doping concentration.…”

“…1. It should be noted that the cross sections, in particular in π-polarization, are much higher than the values reported in [2] and differ significantly from those in [12]. We determined an emission cross section of 5.5 × 10 −20 cm 2 in π-polarization and 2.0 × 10 −20 cm 2 in σ-polarization for the zero-phonon line transitions around 980 nm.…”

“…Due to this low segregation coefficient, there was some ambiguity about the cross-section values for Yb:CALGO in the past, as possibly the doping concentration in the melt was taken for their determination [2,12,13]. For this reason, we thoroughly refined the absorption and emission cross sections.…”

Diode-pumped ultrafast Yb:KGW laser with 56 fs pulses and multi-100 kW peak power based on SESAM and Kerr-lens mode locking

“…A comparison of performance of the diode-pumped Yblasers in the sub-100 fs regime is shown in Figure 3. As can be seen, the generated 56 fs pulses with 450 kW of peak power in our work demonstrate more than one order of magnitude higher average and peak powers when compared to the previous sub-60 fs diode-pumped Yb-lasers [37][38][39][40][41][42]. We believe that such a powerful ultrashort pulse laser source will be attractive for nonlinear frequency conversion into the visible and near-infrared ranges [43][44][45].…”