  We report on fabrication of whispering-gallery-mode microlasers in a Nd:glass
chip by femtosecond laser three-dimensional (3D) micromachining. Main
fabrication procedures include the fabrication of freestanding microdisks
supported by thin pillars by femtosecond laser ablation of the glass substrate
immersed in water, followed by CO2 laser annealing for surface smoothing.
Lasing is observed at a pump threshold as low as ~69 {\mu}W at room temperature
with a continuous-wave laser diode operating at 780nm. This technique allows
for fabrication of microcavities of high quality factors in various dielectric
materials such as glasses and crystals.
