Optoelectronics – basic information and example applications

Optoelectronics is a rapidly growing field that combines electronics and optics to use light to process information.

It is based on the phenomena of interaction of light and other forms of electromagnetic radiation with semiconductor materials. This makes it possible to convert electrical signals to optical and vice versa. Optoelectronic devices use effects such as photoelectricity, photovoltaics, photoemission or electroluminescence to detect, emit and modulate light.

Optoelectronics combines the achievements of chemistry, solid-state physics and electronics to create an interdisciplinary field with a broad spectrum of applications. It includes technologies for acquiring, transmitting, processing and presenting information by means of light. It enables the design of high-speed and high-performance devices such as lasers, radiation detectors, optical modulators and displays.

Optoelectronics plays a key role in today’s telecommunications and information systems. It allows ultra-fast transmission of huge amounts of data using optical fibers. It is also used in medicine, industry, transportation and many other fields. Its importance will grow as the world becomes more digitized and the need for ever faster information processing systems increases. It can be said that optoelectronics is driving the digital revolution and is a key technology of the future.

1. Cells Solar cells use optoelectronics to convert light into energy
   Electricity generation in solar cells that absorb light from the sun is a common application that takes advantage of these effects. The electricity thus generated can be used directly or stored in batteries for later use. Practical applications for solar cells include power generation both on Earth, such as in off-grid homes in remote areas, and in space, such as in satellites.
2. Optoelectronic devices play a key role in applications and products – from computers to communications
   Electroluminescence is another important phenomenon used in optoelectronics. When an electric current flows through some materials, it causes electrons at high energy levels to combine with electron holes and move to more stable lower energy levels, releasing energy in the form of light. LEDs are a common example of the use of electroluminescence. LEDs in various colors are used as power indicators, in digital displays such as in calculators and household appliances, to illuminate signs and street lights, as headlights and car lights, and much more. Vehicle dashboards also often use electroluminescence for illumination.
3. The use of optoelectronics made it possible to develop photocopiers
   Photoconductivity, is the phenomenon of increased conductivity of a material under illumination. This effect depends on higher light intensity generating more electrons and electron holes in some materials, which increases their electrical conductivity. This particular phenomenon of optoelectronics enabled the construction of photocopiers. When a photoconductive surface in a photocopier is exposed to an image, a difference in conductivity is created between the illuminated areas containing no image and the non-illuminated areas containing it. As a result, the powder in the machine is distributed in the form of an image, after which it is fixed on a sheet of paper, completing the copying process.
4. Optoelectronics can be used to automate administrative work in many ways
   These and other optoelectronic effects are being integrated into a huge number of devices and applications in numerous combinations, and even more are under development. Many industries have been revolutionized through the use of optoelectronics. Optoelectronic devices play a key role in applications and products – from computers to communications, medical technology to military equipment, photography and other imaging techniques, and more.

There are a variety of optoelectronic components that convert light signals into electrical signals and vice versa. The most important of these are:

• Photodiodes – semiconductor light sensors made of an active P-N junction that generate current or voltage when light falls on the junction. They have different modes of operation and are used, among others. In medical and industrial equipment.
• Photovoltaic cells – convert solar energy directly into electricity. Widely used in telecommunications systems, marine navigation or rural electrification.
• Photoresistors – light-controlled resistors whose resistance decreases with illumination. Used in light sensors and switches.
• LEDs – semiconductor diodes that emit light through the process of electroluminescence. They are widely used as indicators and light sources in electronics.
• Encoder sensor ICs – convert rotary or linear motion into electrical signals in motion control systems.
• Laser diodes – semiconductor diodes that convert electrical energy into laser light. Used among others. In CD players, medical devices and telecommunications.
• Fiber optics – transmit information in the form of modulated light. Used in telecommunications, sensors and las