Optoelectronics

Optoelectronics is a branch of electronics that studies and exploits the interaction between light and electronic devices. It covers components that emit, detect, regulate, or convert light into electrical signals, and systems that integrate these components. The field blends optics, semiconductor physics, materials science, and electrical engineering and focuses on devices that convert electrical energy into light and vice versa, or manipulate light signals in the electrical domain.

Materials commonly used include gallium arsenide (GaAs), indium phosphide (InP), gallium nitride (GaN), silicon (Si), silicon carbide (SiC), and emerging materials such as perovskites. Key devices include light emitters (light-emitting diodes and laser diodes), detectors (photodiodes and phototransistors, including avalanche photodiodes), solar cells, and image sensors (CCD and CMOS). Optical modulators and switches, photonic integrated circuits, and fiber-optic components are also central. The performance metrics include emission efficiency, responsivity, sensitivity, quantum efficiency, and speed.

Applications span fiber-optic communications, where LEDs or laser diodes supply signals and photodiodes receive them; displays and solid-state lighting; sensing and imaging in medical, environmental, and industrial contexts; spectroscopy and environmental monitoring; and solar energy harvesting.

Historically, optoelectronics advanced with the invention of practical LEDs and lasers in the 1960s, followed by rapid growth in optical communications and imaging technologies. Today the field includes ongoing work in silicon photonics, organic and quantum-dot emitters, perovskites, and integrated photonic circuits, aiming to combine high-speed optical functions with traditional electronics.