Research On Yb³⁺/Er³⁺ Co-doped LaMgB₅O₁₀ Laser Crystal Around 1.55 ?m

The spectroscopic and 1.55 ?m laser performances of a Yb(7.51 at.%):Er(0.68 at.%):LaMgB5O10 crystal grown by the flux method are mainly investigated in this thesis.Absorption cross section at the peak wavelength of 976 nm and stimulated emission cross section at the peak wavelength of 1518 nm for E//Z polarization are 1.68×10-20 cm2 and 0.88×10'20 cm2,respectively.The fluorescence lifetime of 4I13/2 multiplet is 538 ?s and energy transfer efficiency from Yb3+ to Er3+ is 82%.Room-temperature thermal conductivity of the Yb:Er:LaMgBsO10 crystal is about 5.0 Wm-1K-1,which is similar to that of the Yb:Er:YAl3(BO3)4 crystal(4.7 Wm-1K-1).Above parameters imply that the Yb:Er:LaMgBsO10 crystal may be a promising 1.55?m laser gain medium pumped by a continuous-wave 976 nm laser diode.When an X-cut,2.0 mm-thick Yb:Er:LaMgB5O10 crystal with sapphire cooling was end-pumped by a 976 nm laser diode,1568 nm continuous-wave laser with slope efficiency of 16%and maximum output power of 185 mW,and 1567 nm continuous-wave laser with slope efficiency of 23%and maximum output power of 90 mW were realized in a plano-concave and a plano-plano cavities,respectively.It has also shown that the influence of the waist radius of pump beam on 1.55 um continuous-wave laser performance is very serious.When the waist radius of pump beam in the crystal was 45?m,a higher 1.55 ?m continuous-wave laser performance was obtained.Using a 976 nm laser diode with higher power as pumping source in the plano-plano cavity,1567 nm continuous-wave laser with slope efficiency of 16%and maximum output power of 0.47 W was realized.