Where does “optoelectronic” come from?

I need to work through this chain carefully, but there's a significant problem: the chain provided doesn't actually support the word "optoelectronic." The chain shows: English electronic | English electron | Ancient Greek ὀπτός | Latin -icus | Proto-Indo-European -kos This chain traces "electronic" back to "electron" (from Ancient Greek ἤλεκτρον, meaning amber), but "ὀπτός" (meaning "visible" or "seen") doesn't appear in that derivation. Additionally, the chain repeats "Proto-Indo-European -kos" three times without explanation. The word "optoelectronic" is a compound of "opto-" (from Greek ὀπτός, relating to vision/light) + "electronic," but the chain as presented doesn't coherently support this compound or explain how these elements connect.

optoelectronic (English): Of or pertaining to optoelectronics; That has...