DVD photosensor : weekend die-shot

This is unidentified photo-sensor from DVD-RW drive. Most of the work is done by middle quad - it can receive the signal, track focus (via astigmatic focusing) and follow the track. Additional quads are probably here to improve tracking, they are not used as full quads - there are fewer outputs for left and right quads.

Die size 1839x1635 µm.



Closer look at photo-diodes: