Optoelectronics are electronic and semiconductor devices that use light as one of their inputs to function. So it is basically a field of technology which combines the physics of light with the world of electricity. These instruments are based on quantum mechanics principles of light on semiconducting materials, sometimes in the presence of electric fields. By light, we mean visible light as well as invisible forms of radiation such as gamma rays, X-rays, infrared and ultraviolet light.
Optoelectronics encompasses the study, design and manufacture of hardware devices that convert electrical signals into photon signals and vice versa. Optoelectronic devices are electrical-to-optical or optical-to-electrical transducers, or instruments that use such devices in their operation. Optoelectronics includes everything from items that are used to provide lighting, to items which use that light to transmit information. It has a wide-range of applications where strong and reliable lighting is required. Optoelectronics includes many different types of items such as fiber optics, electric eyes, remote sensing systems, medical diagnostic systems and optical information systems.
The family of devices that are covered under optoelectronics includes:
- Photoelectric and photovoltaic devices: these use photosensitive semiconductor materials that release electrons when voltage is passed through them. Some examples are: solar cells, photodiodes, photomultipliers, integrated optical circuits and phototransistors.
- Stimulated emission devices that emit high intensity light when a small voltage is passed through it. Some example devices are: injection laser diodes and lasers.
- Photoconductivity devices use semiconductors, whose resistance changes with the amount of light. Some example devices are: charge-coupled imaging units, light-dependent resistors and photoconductive camera tubes.
- Lossev effect devices like light-emitting diodes (LED).
- Photoemissivity devices such as the photoemissive camera tube.
The above devices are used in many different applications such as digital cameras, lighting, electronic displays, special lighting in domestic and automobile electronics, night vision devices, solar panels for electricity generation, etc.
Optoelectronics is often mistakenly referred to as or confused with electro-optics. However, electro-optics is actually a wider branch of physics that deals with all interactions between light and electric charge, whether or not they form part of an electronic device.