Science & TechnologyGreek → English
Photodiode
/ˌfoʊtoʊˈdaɪoʊd/noun
A semiconductor device that converts light into an electric current.
The Greek roots
φῶς
phôs
light
δι-
di-
two
ὁδός
hodós
way, road
Literally: “light two-way”
The story of the word
Three Greek pieces stacked by three different generations of engineers. ὁδός, road, came from Faraday's electrode in 1834; δι- was bolted on when wireless telegraphy needed a name for the two-electrode valve; φῶς arrived when the same junction was asked to detect light. Photodiodes sit behind every barcode scanner, pulse oximeter and television remote, and a solar cell is the same physics run at scale.
- How it travelled
- Ancient Greek → scientific coinage → English
- First recorded
- 20th century
Same family
diodephotographphotonelectrodetriode
In a sentence
A photodiode in the lid tells the laptop when to dim the screen.