the branch of electronics dealing with devices that generate, transform, transmit, or sense optical, infrared, or ultraviolet radiation, as cathode-ray tubes, electroluminescent and liquid crystal displays, lasers, and solar cells.
British Dictionary definitions for optoelectronics
optoelectronics
/ˌɒptəʊɪlɛkˈtrɒnɪks/
noun
1.
(functioning as sing) the study or use of devices in which an optical input produces an electrical output, or in which electrical stimulation produces visible or infrared output