Pulsed laser action in LiYF4:Er3+, Ho3+at 77°K

Pulsed laser action at 77°K has been demonstrated in LiYF
4
:Er
³⁺
, Ho
³⁺
with an emission wavelength of 2.066 μ. The laser transition is the
⁵
I_{7} \rightarrow
⁵
I
8
in trivalent holmium, and there is evidence of energy transfer from erbium to holmium. The fluorescent lifetime is approximately 20 ms, and the pulsed threshold is 40 joules.