A transparent chip substrate or {HEAD ~ appropriate holes} within {TAIL ~ the substrate} would allow the external optical devices to be positioned within the semispherical volume beneath the chip 
within
A transparent chip substrate or { HEAD ~ appropriate holes } within { TAIL ~ the substrate } would allow the external optical devices to be positioned within the semispherical volume beneath the chip
OTH OTH OTH OTH OTH 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 OTH OTH