A micro-optic drill was a small hand-held device that could drill holes of microscopic sizes into solid materials.
In 2368, Geordi La Forge hooked up a plasma inverter and a laser scanner and used the two combined devices to send enough plasma through a hole, created by means of a micro-optic drill to temporarily plasma-shock Deanna Troi and Miles O'Brien who were taken over by Ux-Mal criminals. (TNG: "Power Play")