| Abstrakt: |
We report on the development of novel saturable absorbers for erbium lasers based on transparent glass-ceramics (GCs) containing a mixture of cobalt-doped β-willemite, Co 2+ :β-Zn 2 SiO 4 , and zinc oxide, Co 2+ :ZnO, nanosized (10-14 nm) crystals. The structure of the parent glass and GCs is studied by x-ray diffraction, differential scanning calorimetry, transmission electron microscopy, and Raman spectroscopy. Variations of absorption spectra with heat-treatment reveal that Co 2+ ions from the parent glass enter the crystals of ZnO and β-willemite. GCs are characterized by a broad absorption band due to the A 2 4(F4)→T 1 4(F4) transition of Co 2+ ions in tetrahedral sites spanning up to ∼1.74 μm, relatively low saturation fluence, F S =0.75 J/cm 2 at 1.54 μm, short recovery time, τ=830 ns, and high laser damage threshold, ∼14 J/cm 2 . By using the developed GCs in a diode-side-pumped Er, Yb:glass laser, 0.77 mJ/45 ns pulses are generated. |
