The word ‘photonics’ is derived from the Greek word “phos” meaning light; it appeared in the late 1960s to describe a research field whose goal was to use light to perform functions that traditionally fell within the typical domain of electronics, such as telecommunications, information processing, etc.
Photonics as a field began with the invention of the laser in 1960. Other developments followed: including the laser diode in the 1970s, optical fibers for transmitting information, and the erbium-doped fiber amplifier. These inventions formed the basis for the telecommunications revolution of the late 20th century and provided the infrastructure for the Internet.
Though coined earlier, the term photonics came into common use in the 1980s as fiber-optic data transmission was adopted by telecommunications network operators. At that time, the term was used widely at Bell Laboratories. Its use was confirmed when the IEEE Lasers and Electro-Optics Society established an archival journal named Photonics Technology Letters at the end of the 1980s.
During the period leading up to the dot-com crash circa 2001, photonics as a field focused largely on telecommunications. However, photonics covers a huge range of science and technology applications, including: laser manufacturing, biological and chemical sensing, medical diagnostics and therapy, display technology, and optical computing.
Various non-telecom photonics applications exhibit strong growth, particularly since the dot-com crash, partly because many companies have been looking for new application areas. Further growth of photonics is likely if current silicon photonics developments are successful.
Classical Optics
Photonics is closely related to optics. However, optics preceded the discovery that light is quantized (when Albert Einstein explained the photoelectric effect in 1905). Optics tools include the refracting lens, the reflecting mirror, and various optical components known prior to 1900. Key tenets of classical optics, such as Huygen’s principle, Maxwell’s equations, and wave equations, 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, e.g., 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 typically used for surveillance by civilian or government organizations.
Emerging Fields
Photonics also relates to the emerging science of quantum information in those cases where it employs photonic methods. Other emerging fields include opto-atomics, in which devices integrate both photonic and atomic devices for applications such as precision timekeeping, navigation, and metrology; polaritonics, which differs from photonics in that the fundamental information carrier is a polariton, which is a mixture of photons and phonons, and operates in the range of frequencies from 300 gigahertz to approximately 10 terahertz.