What is photonics?

Photonics deals with light and its technical use. The term photonics is composed of the term photon and the suffix of electronics. Today, this includes optical technologies that are used to generate, amplify, transmit, control and measure electromagnetic radiation. Photons designate the smallest discrete energy packets of light. Electrons interact with photons, resulting in the interface with electronics. (Steglich & Heise, 2019; Bäuerle, 2009)

What is light and how can we use it?

Light is an elementary phenomenon. It is the basis for the development of life and surrounds us everywhere, at all times. For the majority of mankind, this is taken for granted and one forgets the multitude of things in daily life that are only possible because of light. On the one hand, it allows us to see colors, but on the other hand, it also transmits energy so that we feel warmth. Plants need light for photosynthesis and in other creatures, such as humans, it influences hormone release and causes a feeling of satisfaction.

Due to its versatile properties and various applications, we began to use light for technical purposes as well. This laid the foundation for photonics, which could be developed further and further through technological progress and opened up new possibilities.

Today, lighting technology applications can be found in a large part of everyday devices such as smartphones, screens or lighting in general. But light has also become an indispensable tool for industry and medicine. This is especially true as climate and environmental protection, combined with the expansion of mobility, energy, communication, safety and health, are main present challenges in our modern society.

Topics such as energy and resource conservation become the cornerstone of the latest technical achievements. Modern applications that are not environmentally compatible are currently hardly popular. This is where photonics plays a key role. As a result, many processes can be made more efficient and a reduction in waste and emissions, among other things, can be enabled. Thus, photonic technologies have a considerable potential for the future, which, if exploited appropriately, could make a decisive contribution to improving the quality of life of future generations.


The human eye can only detect light with wavelengths of 380 nm to 780 nm                            (1 nm = 10-9 m), the so-called “visible light” through which we perceive objects and especially colors. (Slabke, 2018)

Under ideal conditions in vacuum, light reaches nearly     300,000 km/s, the highest possible speed in the universe, also known as the speed of light. (Steglich & Heise, 2019)

Bundled, light can achieve a power of nearly 1 billion megawatts for a fraction of a second. This is equivalent to approximately 1360 billion horsepower, or 1.3 billion Bugatti Veyrons, which, with over 1000 horsepower, is considered one of the most powerful supercars in the world. (Steglich & Heise, 2019; Denz, 2019; Winkelmann, 2019)

Light is a special case of electromagnetic radiation and has both particle and wave properties. (Demtröder, 2016)

Light of several different colors or wavelengths is added together in the eye, whereby usually only one color is recognizable for us.


  • Light-emitting diodes – short – LEDs, are semiconductor components that can emit light.
  • Laser – The term laser stands for “Light Amplification by Stimulated Emission of Radiation” and roughly means light amplification by multiplying light particles.
  • Photovoltaics – Photovoltaics describes the conversion of radiant energy into electrical energy using solar cells.
  • Optical sensors, lenses and mirrors in cameras, binoculars, telescopes …

Application areas of photonics

Optical communication uses photons as information carriers, employing laser light that can travel long distances in fiber optic cables with little loss.

Photonics is present in many forms, whether it is used to “laser away” defective vision, to capture and manipulate tiny viruses and bacteria using laser tweezers, or in the form of optoelectronic pulse measuring devices.

In industrial manufacturing, laser radiation is exploited to precisely introduce large amounts of energy into a system in a very short period of time, allowing defined layers of a material to be heated, melted or vaporized without affecting the surrounding material. These include:

  • Laser cutting, welding, soldering
  • Laser polishing, hardening, alloying and coating
  • Generation of 3D structures (3D printing, additive manufacturing)
  • Light barrier technology for the measurement of piece numbers on an assembly line
  • Measurement of topography and distances
  • Speed measurements
  • Flat screens, CDs, DVDs and Blu-rays

  • Bar code reader, laser printer

  • LEDs


Bäuerle, D. (2009). Laser – Grundlagen und Anwendungen in Photonik, Technik, Medizin und Kunst. Weinheim: WILEY-VCH.

Demtröder, W. (2016). Experimentalphysik 3 – Atome, Moleküle und Festkörper. 5. Auflage Hrsg. Berlin Heidelberg: Springer Spektrum.

Denz, C. (2019). Photonik – Von der klassichen Optik zur Zukunft des Lichts. In: D. Duchardt, A. B. Bossman & C. Denz, Hrsg. Vielfältige Physik – Wissenschaftlerinnen schreiben über ihre Forschung. Berlin: Springer Spektrum, pp. 196-206.

Slabke, U. (2018). LED-Beleuchtungstechnik – Grundwissen für Planung, Auswahl und Installation. Berlin: VDE Verlag.

Steglich, P. & Heise, K. (2019). Photonik einfach erklärt – Wie Licht die Industrie revolutionierte. Wiesbaden: Springer Spektrum.

Winkelmann, S. (2019). Bugatti Veyron 16.4 – Ein Sportwagen der Superlative. [Online] Available at: [Zugriff am 30. 12. 2019]