Whispering gallery modes in simply made glass microspheres

A simple technique to form glass microresonators is proposed and used to make microresonators of samarium-doped phosphate glass. Measured in the vicinity of ⁴G_5/2 - ⁶H_7/2 transition of Sm³⁺ ion photoluminescence spectra of the microresonators gave the value of Q-factor approximately 6000.