Editing Photonics (section)

==Relationship to other fields==

===Classical optics===
Photonics is closely related to [[optics]]. Classical optics long preceded the discovery that light is quantized, when [[Albert Einstein]] famously explained the [[photoelectric effect]] in 1905. Optics tools include the refracting [[lens]], the reflecting [[mirror]], and various optical components and instruments developed throughout the 15th to 19th centuries. Key tenets of classical optics, such as [[Huygens Principle]], developed in the 17th century, [[Maxwell's Equations]] and the wave equations, developed in the 19th, do not depend on quantum properties of light.

===Modern optics===
Photonics is related to [[quantum optics]], [[optomechanics]], [[electro-optics]], [[optoelectronics]] and [[quantum electronics]]. However, each area has slightly different connotations by scientific and government communities and in the marketplace. Quantum optics often connotes fundamental research, whereas photonics is used to connote applied research and development.

The term ''photonics'' more specifically connotes:
* The particle properties of light,
* The potential of creating signal processing device technologies using photons,
* The practical application of optics, and
* An analogy to [[electronics]].

The term [[optoelectronics]] connotes devices or circuits that comprise both electrical and optical functions, i.e., a thin-film semiconductor device. The term [[electro-optics]] came into earlier use and specifically encompasses nonlinear electrical-optical interactions applied, e.g., as bulk crystal modulators such as the [[Pockels cell]], but also includes advanced imaging sensors.

An important aspect in the modern definition of Photonics is that there is not necessarily a widespread agreement in the perception of the field boundaries. Following a source on optics.org,<ref name=":0">{{cite web |last1=Optics.org |title=Optics or photonics: what's in a name? |url=https://optics.org/article/32348 |publisher=Optics.org}}</ref> the response of a query from the publisher of Journal of Optics: A Pure and Applied Physics to the editorial board regarding streamlining the name of the journal reported significant differences in the way the terms "optics" and "photonics" describe the subject area, with some description proposing that "photonics embraces optics". In practice, as the field evolves, evidences that "modern optics" and Photonics are often used interchangeably are very diffused and absorbed in the scientific jargon.

===Emerging fields===
Photonics also relates to the emerging science of [[quantum information]] and quantum optics. Other emerging fields include:

* [[Photoacoustic imaging|Optoacoustics or photoacoustic imaging]] where [[laser]] energy delivered into biological tissues will be absorbed and converted into heat, leading to [[ultrasonic]] emission. 
* [[Optomechanics (science)|Optomechanics]], which involves the study of the interaction between light and mechanical vibrations of mesoscopic or macroscopic objects; 
* [[Optomics]], in which devices integrate both photonic and atomic devices for applications such as precision timekeeping, navigation, and metrology; 
* [[Plasmonics]], which studies the interaction between light and [[plasmon]]s in dielectric and metallic structures. Plasmons are the quantizations of [[plasma oscillation]]s; when coupled to an electromagnetic wave, they manifest as [[surface plasmon polariton]]s or [[localized surface plasmon]]s. 
* [[Polaritonics]], which differs from photonics in that the fundamental information carrier is a [[polariton]]. Polaritons are a mixture of photons and [[phonons]], and operate in the range of frequencies from 300 [[gigahertz]] to approximately 10 [[Terahertz (unit)|terahertz]].
* [[Programmable photonics]], which studies the development of photonic circuits that can be reprogrammed to implement different functions in the same fashion as an [[FPGA|electronic FPGA]]