Optoelectronics, often known as optronics, is a subfield of photonics that focuses on the research and application of electronic devices and systems that are able to locate, detect, and regulate light. In this context, the term "light" frequently encompasses not only visible light but also other kinds of radiation that are not visible to the human eye, such as gamma rays, X-rays, ultraviolet, and infrared. Electrical-to-optical or optical-to-electrical transducers are examples of optoelectronic devices. Instruments that use such devices in their functioning are also examples of optoelectronic devices.