In one embodiment the light is confined from {HEAD ~ both the internal and the external sides} of {TAIL ~ the device} forming a guiding channel or just by the external side forming a disk resonator 
In one embodiment the light is confined from { HEAD ~ both the internal and the external sides } of { TAIL ~ the device } forming a guiding channel or just by the external side forming a disk resonator
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH