Czochralski growth and characterization of Er3+,Yb3+:YCa4O(BO3)3 single crystals

Calcium-yttrium oxyborate single crystals YCa
₄
O(BO
₃
)
₃
co-doped erbium and ytterbium ions (Er,Yb:YCOB) (1,5 aT.% Er
³⁺
, 30 aT.% Yb
³⁺
and 2 aT.% Er
³⁺
, 20 aT.% Yb
³⁺
) were grown by Czochralski method. Absorption and photoluminescence properties of the Er, Yb: YCOB crystals were studied. The emergence of intensive luminescence near 1,5 μm indicates the effective energy transfer from the multiplets
²
F
_5/2
of the Y
^b3+
ions to the
⁴
I11/2 states of Er
^3
+
ions when pumping in the absorption band of ytterbium (940 nm). For the first time in the crystalline material Er, Yb: YCOB, a single pulse lasing in a Q-switch mode with the use of passive modulators based on Co: MALO was obtained.