The second optical window may be formed in a straight line with {HEAD ~ an optical input/output section} formed in {TAIL ~ the memory die} and the first optical window 
formed in
The second optical window may be formed in a straight line with { HEAD ~ an optical input / output section } formed in { TAIL ~ the memory die } and the first optical window
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH