  We report self-pulsation in an erbium-doped silica toroidal microcavity laser
coupled to a tapered fiber and investigate the effects of pump power and
taper-cavity coupling condition on the dynamic behaviors of the pulse train.
The microcavity is pumped at 1444.8 nm, and lasing occurs at 1560.2 nm with a
threshold of 12 {\mu}W. Experimental results are interpreted within the
framework of ion-pair induced self-quenching model.
