Concept, history and types of optics

We explain what optics is, its history, impact on other sciences and how physical, geometric and modern optics differ.

Optics studies the properties of light and how they can be used.

What is optics?

Optics is a branch of physics that is dedicated to the study of visible light : its properties and behavior.It also analyzes its possible applications in human life, as is the construction of instruments to detect or use it.

Light has been defined by optics as a strip of electromagnetic emissions , whose behavior is similar to other ways invisible (to us) of the electromagnetic spectrum, such as ultraviolet or infrared radiation.

This means that their behavior can be described according to wave mechanics (except in very specific contexts in which light acts as a particulate) and the approaches of classical electrodynamics of light.

Optics is a very important research field that nourishes other sciences with tools, especially astronomy, engineering, photography and medicine (ophthalmology and optometry).To her we owe the existence of mirrors, lenses , telescopes, microscopes, lasers and fiber optic systems.

It can serve you: Speed ​​of light

History of optics

Optics allowed vital inventions for science, such as microscopes.

The field of optics has been part of human concerns since ancient times. The first attempts at known lenses date from the ancient Egypt or ancient Mesopotamia, such as the lens of Nirmud (700 BC) manufactured in Assyria.

The ancient Greeks also worried about understanding the nature of light , which they understood based on two perspectives: their reception or vision, and their emission, since the ancient Greeks thought that objects they issued copies of themselves through light (called eidola ).Philosophers such as Deocritus, Epicurus, Platon and Aristotle profusely studied optics.

The relief of these scholars was constituted by Islamic alchemists and scientists during medieval European times, such as Al-Kindi (c.801-873) and especially Abu Ali-al-Hasan or Alhazen (965-1040), who is considered the father of optics for his Book of optics (11th century), where he explored the phenomena of refraction and reflection.

The European Renaissance brought that knowledge to the West, especially thanks to Roberto Grosseteste and Roger Bacon. The first practical glasses were manufactured in Italy around 1286 .Since then, the application of optical lenses to different scientific purposes have not ceased.

Thanks to the optics, geniuses such as Copernico, Galileo Galilei and Johannes Kepler were able to carry out their astronomical studies.Later, the first microscopes allowed the discovery of microbial life and the beginning of biology and medicine modern. The entire Scientific Revolution is largely due to the contribution of optics .

Physical optics

Physical optics is one that considers light as a wave propagating in space .That is to say that it is the branch of optics that is most faithful to the principles and physics reasoning, leveraging prior knowledge such as Maxwell's Equations, to cite an important example.

In this way, cares about physical phenomena such as interference, polarization or diffraction .In addition, it proposes predictive models to know how light will behave in certain situations or in certain media, when not of numerical simulation.

Geometric optics

Geometric optics allows you to study phenomena such as rainbows and prisms.

Geometric optics is born from the geometric application of phenomenological laws around refraction and reflection by Willebrord Snel van Royen (1580-1626), the Dutch scientist known as Snell.

For this, this branch of optics starts from the existence of a light ray, whose behavior is described by the rules of the geometry to find formulas corresponding to lenses, mirrors and diopters.Thus it is possible to study phenomena such as rainbows, the propagation of light and prisms .All using the language of mathematics.

Modern optics

The contemporary branch of optics emerges with quantum physics and the new fields of knowledge that the latter made possible, as well as its possible applications by engineering.that way, modern optics comprises a huge variety of new fields of research regarding light and its applications, which include:

• The mechanisms of laser (amplification of light by simulated emission of radiation).


• The photoelectric cells , LED lights and metamaterials.


• The optoelectronica , hand in hand with computer science, and digital image processing.


• The lighting engineering , with applications in photography, film and other fields.


• Quantum optics and the photon physical study as a light particle and light wave at the same time.


• The atmospheric optics and the understanding of atmospheric lighting processes.

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