subsequent to {HEAD ~ bonding} removing a portion of {TAIL ~ the single crystal} which defines the cavity, 
subsequent to { HEAD ~ bonding } removing a portion of { TAIL ~ the single crystal } which defines the cavity ,
OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH