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