Patent ID: 8853931

Claim:
An electrodeless plasma lamp comprising: a lamp body; a power source configured to provide radio-frequency (RF) power via a feed to the lamp body; an elongate bulb proximate the lamp body, the bulb containing a fill; a first conductive element including a first side with a first protrusion, the first side having a first width greater than the first protrusion's width; and a second conductive element including a second side with a second protrusion, the second side having a second width greater than the second protrusion's width, the first side and second side facing each other and being spaced apart by a first distance and being configured to couple the RF power via an electric field to the fill to form at least one plasma arc, the first protrusion and the second protrusion extending towards each other and being spaced apart by a second distance that is less than the first distance, the first and second protrusions to provide localized enhancement of the electric field at the first side and the second side, wherein the first side and the second side extend transverse to a longitudinal axis of the bulb.