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 the physical who is dedicated to the study of light visible: its properties and its behavior. It also analyzes its possible applications in the life of the human being, as is the construction of instruments to detect or use it.

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

This means that its behavior can be described according to the mechanics of waves (except in very specific contexts where light acts as a particle) and the approaches of classical electrodynamics of light.

Optics is a very important field of research that provides tools for others Sciences, especially to the astronomy, engineering, Photography and medicine (ophthalmology and optometry). To her we owe the existence of mirrors, lenses, telescopes, microscopes, lasers and systems optical fiber.

History of optics

Optics allowed inventions vital to science, such as microscopes.

The field of optics has been part of the concerns of the human being since ancient times. The earliest known lens attempts date back to ancient Egypt or ancient Mesopotamia, such as the Nirmud lens (700 BC) made in Assyria.

The ancient Greeks were also concerned with understanding the nature of light, which they understood based on two perspectives: its reception or view and its emission, since the ancient greeks thought that objects emitted copies of themselves through light (called eidola). Philosophers like Deócritus, Epicurus, Plato and Aristotle they studied optics profusely.

These scholars were replaced by the alchemists and Islamic scientists during the medieval times such as Al-Kindi (c. 801-873) and especially Abu Ali-al-Hasan or Alhazén (965-1040), considered the father of optics for his Optics book (11th century), where he explores the phenomena of refraction and reflection.

The Renaissance European 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 for various scientific purposes has not ceased.

Thanks to optics, geniuses of the stature of Copernicus, Galileo Galilei and Johannes Kepler were able to carry out their astronomical studies. Later, the first microscopes allowed the discovery of life microbial and the start of the biology and modern medicine. The Scientific revolution entire is due, to a large extent, to the contribution of optics.

Physical optics

Physical optics is one that considers light as a wave propagating in the space. It is the branch of optics that is most faithful to the principles and reasonings of physics, making use of knowledge previous such as Maxwell's Equations, to cite an important example.

In that way, it worries 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 notsystems numerical simulation.

Geometric optics

Geometric optics allow the study of phenomena such as rainbows and prisms.

Geometric optics is born from the geometric application of the laws phenomenological 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 geometry to find formulas for lenses, mirrors and diopters. In this way it is possible to study phenomena such as Rainbow, the propagation of light and prisms. All this using the language of the math.

Modern optics

The contemporary branch of optics arises with quantum physics and the new fields of knowledge that the latter made possible, as well as its eventual applications in engineering. Thus, modern optics encompasses an enormous variety of new fields of research regarding light and its applications, including:

  • The mechanisms of laser (amplification of light by simulated emission of radiation).
  • Photoelectric cells, LED lights and metamaterials.
  • Optoelectronics, hand in hand with computing, and digital image processing.
  • Lighting engineering, with applications in the Photography, the movie theater and other fields.
  • Quantum optics and the physical study of the photon as a light particle and a light wave at the same time.
  • Atmospheric optics and the understanding of atmospheric light processes.
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