Photonics is the study of the generation, emission, propagation, reception and detection of light. It includes both classical optics and quantum optics. Its applications are found in a wide range of areas including communications, information processing, sensing and imaging.
The term “photonics” was first coined in an article published in 1960 by Gordon Gould while he was a graduate student at Columbia University. In this article, Gould proposed the use of optical amplifiers to overcome some of the limitations of electronics at that time. The word “photonics” is derived from the Greek word for light, “phos”.
The field of photonics has grown rapidly since its inception and there are now several international organizations dedicated to promoting research and development in this area. These include the International Society for Optics and Photonics (SPIE) and the Optical Society (OSA).
There are many different types of photons, each with their own unique properties. The most common type of photon is the electromagnetic photon, which travels at the speed of light and has an electric and magnetic field component. Other types of photons include acoustic photons (sound waves), spin photons (angular momentum), plasmonic photons (surface waves on metals) and photonic crystals (light traveling through a periodic structure).
Photons can be generated using a variety of methods including thermal radiation, electrical conduction, laser amplification or spontaneous emission. They can also be detected using a variety of methods such as photoelectric effect detectors, bolometers or photoconductors.
The study of photonics has led to many important discoveries and inventions such as lasers, fiber optics and solar cells. It has also resulted in new technologies such as optical coherence tomography which is used for medical imaging purposes.