光源

guāngyuán
light source

CEDICT

light source (source of illumination)

Wiktionary

能发出光波的物体。如太阳、日光灯等。

重編國語辭典

Entry Composition

1 光 guāng
  1. bright; shiny
  2. only; merely
  3. used up; finished
  4. to leave (a part of the body) uncovered

classifier: 道
2 源 yuán
  1. root
  2. source
  3. origin