An optical semiconductor device includes a plurality of {HEAD ~ electrodes} formed on {TAIL ~ a common side} of a substrate 
An optical semiconductor device includes a plurality of { HEAD ~ electrodes } formed on { TAIL ~ a common side } of a substrate
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH