Fabrication of microtoroid resonators on LiNbO3

This paper proposes a new microtoroid fabrication technique and successfully produces the first high Q-factor microtoroid resonator on LiNbO₃. The novel fabrication technique uses selective ion implantation and chemical etching to produce the microdisk structure. By the combined effects of gravity force and surface tension, the thickness of the microdisk rim is increased and thus the microtoroid structure is formed. The microtoroid structure enhances the confinement of the resonant field and increases the intrinsic Q factor. After the 3-hour reverse thermal reflow, the measured intrinsic Q factor is as high as 2.3×10⁴.