Devices or components that generate, detect, source and/or control light. These can either convert electrical energy to optical energy or vice versa.
Opto-Electronics also known as Optronics (or Photo-electronics) is an emerging field in technology. Essentially, such products are designed with application of both optics and electronics research. Given the emerging nature of the field, the range of products is broad. These include optocouplers, light-emitting diodes (LEDs), displays, etc.