Array ( [0] => {{Short description|Technical applications of optics}} [1] => {{More citations needed|date=April 2013}} [2] => [[File:Prism flat rainbow.jpg|thumb|right|300px|[[Dispersion (optics)|Dispersion]] of [[light]] (photons) by a prism]] [3] => [4] => '''Photonics''' is a branch of [[optics]] that involves the application of generation, detection, and manipulation of [[light]] in form of [[photon]]s through [[Emission (electromagnetic radiation)|emission]], [[Transmission (telecommunications)|transmission]], [[modulation]], [[signal processing]], switching, [[optical amplifier|amplification]], and [[photodetector|sensing]].{{cite book|author=Chai Yeh|title=Applied Photonics|url=https://books.google.com/books?id=1kTInFpx8m8C&pg=PA1|date=2 December 2012|publisher=Elsevier|isbn=978-0-08-049926-0|pages=1–}}{{cite book|author=Richard S. Quimby|title=Photonics and Lasers: An Introduction|url=https://books.google.com/books?id=82f-gIvtC7wC|date=14 April 2006|publisher=John Wiley & Sons|isbn=978-0-471-79158-4}} Photonics is closely related to quantum electronics, where quantum electronics deals with the theoretical part of it while photonics deal with its engineering applications. Though covering all light's technical applications over the whole [[light spectrum|spectrum]], most photonic applications are in the range of visible and near-[[infrared]] light. The term photonics developed as an outgrowth of the first practical semiconductor light emitters invented in the early 1960s and optical fibers developed in the 1970s. [5] => [6] => ==History== [7] => The word 'Photonics' is derived from the Greek word "phos" meaning light (which has genitive case "photos" and in compound words the root "photo-" is used); 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.{{citation needed|date=August 2017}} [8] => [9] => An early instance of the word was in a December 1954 letter from [[John W. Campbell]] to [[Gotthard Günther|Gotthard Gunther]]:
Incidentally, I’ve decided to invent a new science — photonics. It bears the same relationship to Optics that electronics does to electrical engineering. Photonics, like electronics, will deal with the individual units; optics and EE deal with the group-phenomena! And note that you can do things with electronics that are impossible in electrical engineering!{{Cite book |last=Campbell |first=John W. |title=The John W. Campbell Letters With Isaac Asimov and A.E. van Vogt, Volume II |date= |publisher=AC Projects, Inc |year=1991 |isbn=9780931150197 |editor-last=Chapdelaine |editor-first=Perry A. |chapter=December 14, 1954}}
Photonics as a field began with the invention of the [[maser]] and [[laser]] in 1958 to 1960. Other developments followed: the [[laser diode]] in the 1970s, [[optical fiber]]s for transmitting information, and the [[optical amplifier|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]]. [10] => [11] => Though coined earlier, the term photonics came into common use in the 1980s as fiber-optic data transmission was adopted by telecommunications network operators.{{citation needed|date=August 2017}} At that time, the term was used widely at [[Bell Laboratories]].{{citation needed|date=August 2017}} Its use was confirmed when the [[IEEE Lasers and Electro-Optics Society]] established an archival journal named [[IEEE Photonics Technology Letters|Photonics Technology Letters]] at the end of the 1980s.{{citation needed|date=August 2017}} [12] => [13] => During the period leading up to the [[dot-com crash]] circa 2001, photonics was a field focused largely on optical 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 [[Photonic computing|optical computing]]. Further growth of photonics is likely if current [[silicon photonics]] developments are successful.Responsive Photonic Nanostructures: Smart Nanoscale Optical Materials, Editor: Yadong Yin RSC Cambridge 2013 https://pubs.rsc.org/en/content/ebook/978-1-84973-653-4 [14] => [15] => ==Relationship to other fields== [16] => [17] => ===Classical optics=== [18] => 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 (optics)|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. [19] => [20] => ===Modern optics=== [21] => 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. [22] => [23] => The term ''photonics'' more specifically connotes: [24] => * The particle properties of light, [25] => * The potential of creating signal processing device technologies using photons, [26] => * The practical application of optics, and [27] => * An analogy to [[electronics]]. [28] => [29] => 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. [30] => [31] => 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,{{cite web |last1=Optics.org |title=Optics or photonics: what’s in a name? |url=https://optics.org/article/32348 |publisher=Optics.org}} 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. [32] => [33] => ===Emerging fields=== [34] => Photonics also relates to the emerging science of [[quantum information]] and quantum optics. Other emerging fields include: [35] => [36] => * [[Photoacoustic imaging|Optoacoustics or photoacoustic imaging]] where [[laser]] energy delivered into biological tissues will be absorbed and converted into heat, leading to [[Ultrasound|ultrasonic]] emission. [37] => * [[Optomechanics]], which involves the study of the interaction between light and mechanical vibrations of mesoscopic or macroscopic objects; [38] => * [[Optomics]], in which devices integrate both photonic and atomic devices for applications such as precision timekeeping, navigation, and metrology; [39] => * [[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. [40] => * [[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]]. [41] => * [[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]] [42] => [43] => ==Applications== [44] => [[Image:Aphrodita aculeata (Sea mouse).jpg|thumb|A [[sea mouse]] (''Aphrodita aculeata''),{{cite news|url=https://news.bbc.co.uk/1/hi/sci/tech/1099278.stm |title=Sea mouse promises bright future |work=BBC News |date=2001-01-03 |access-date=2013-05-05}} showing colorful spines, a remarkable example of photonic engineering by a living organism]] [45] => [46] => Applications of photonics are ubiquitous. Included are all areas from everyday life to the most advanced science, e.g. light detection, [[telecommunications]], [[Data processing|information processing]], [[photovoltaics]], [[photonic computing]], [[lighting]], [[metrology]], [[spectroscopy]], [[holography]], [[medicine]] (surgery, vision correction, endoscopy, health monitoring), [[biophotonics]], [[military technology]], laser material processing, art diagnostics (involving [[Infrared|InfraRed]] Reflectography, [[X-ray|Xrays]], [[Ultraviolet|UltraViolet]] fluorescence, [[X-ray fluorescence|XRF]]), [[agriculture]], and [[robotics]]. [47] => [48] => Just as applications of electronics have expanded dramatically since the first [[transistor]] was invented in 1948, the unique applications of photonics continue to emerge. Economically important applications for [[semiconductor]] photonic devices include optical data recording, fiber optic telecommunications, [[laser printing]] (based on xerography), displays, and [[laser pumping|optical pumping]] of high-power lasers. The potential applications of photonics are virtually unlimited and include chemical synthesis, medical diagnostics, on-chip data communication, sensors, laser defense, and [[fusion energy]], to name several interesting additional examples. [49] => [50] => * Consumer equipment: [[barcode]] scanner, printer, CD/DVD/Blu-ray devices, [[remote control]] devices [51] => * [[Telecommunications]]: [[fiber-optic communication]]s, optical down converter to microwave [52] => * [[Renewable Energy]]: [[photovoltaics|Solar power systems]] [53] => * [[Medicine]]: correction of poor eyesight, [[laser surgery]], surgical endoscopy, tattoo removal [54] => * Industrial [[manufacturing]]: the use of lasers for welding, drilling, cutting, and various methods of surface modification [55] => * [[Construction]]: laser leveling, laser rangefinding, smart structures [56] => * [[Aviation]]: photonic [[gyroscope]]s lacking mobile parts [57] => * [[Military]]: IR sensors, command and control, navigation, search and rescue, mine laying and detection [58] => * [[Entertainment]]: [[laser show]]s, beam effects, [[holographic art]] [59] => * [[Data processing|Information processing]] [60] => * [[Passive daytime radiative cooling]] [61] => * [[Sensors]]: [[LIDAR]], sensors for consumer electronics [62] => * [[Metrology]]: time and frequency measurements, [[rangefinder|rangefinding]] [63] => * [[Photonic computing]]:Archived at [https://ghostarchive.org/varchive/youtube/20211211/XVr_M9F-OEQ Ghostarchive]{{cbignore}} and the [https://web.archive.org/web/20191130094732/https://www.youtube.com/watch?v=XVr_M9F-OEQ Wayback Machine]{{cbignore}}: {{citation|url=https://youtube.com/watch?v=XVr_M9F-OEQ| title=- YouTube }}{{cbignore}} clock distribution and communication between [[computer]]s, [[printed circuit board]]s, or within optoelectronic [[integrated circuit]]s; in the future: [[quantum computer|quantum computing]] [64] => [65] => Microphotonics and nanophotonics usually includes [[photonic crystal]]s and [[solid state device]]s.{{cite book|author1=Hervé Rigneault|author2=Jean-Michel Lourtioz|author3=Claude Delalande |author4=Ariel Levenson |title=Nanophotonics|url=https://books.google.com/books?id=ETSFSod7MfkC&pg=PA5|date=5 January 2010|publisher=John Wiley & Sons|isbn=978-0-470-39459-5|pages=5–}} [66] => [67] => ==Overview of photonics research== [68] => The science of photonics includes investigation of the [[emission (electromagnetic radiation)|emission]], transmission, [[amplifier|amplification]], detection, and [[modulation]] of light. [69] => [70] => ===Light sources=== [71] => Photonics commonly uses semiconductor-based light sources, such as [[light-emitting diode]]s (LEDs), [[superluminescent diode]]s, and lasers. Other light sources include [[single photon sources]], [[fluorescent lamp]]s, [[cathode ray tube]]s (CRTs), and [[plasma screen]]s. Note that while CRTs, plasma screens, and [[organic light-emitting diode]] displays generate their own light, [[liquid crystal display]]s (LCDs) like [[TFT screen]]s require a [[backlight]] of either [[cold cathode fluorescent lamp]]s or, more often today, LEDs. [72] => [73] => Characteristic for research on semiconductor light sources is the frequent use of [[III-V semiconductor]]s instead of the classical semiconductors like [[silicon]] and [[germanium]]. This is due to the special properties of [[III-V semiconductor]]s that allow for the implementation of [[light source|light emitting device]]s. Examples for material systems used are [[gallium arsenide]] (GaAs) and [[aluminium gallium arsenide]] (AlGaAs) or other [[compound semiconductor]]s. They are also used in conjunction with silicon to produce [[hybrid silicon laser]]s. [74] => [75] => ===Transmission media=== [76] => Light can be transmitted through any [[transparency and translucency|transparent]] medium. [[Optical fiber|Glass fiber]] or [[plastic optical fiber]] can be used to guide the light along a desired path. In [[optical communication]]s optical fibers allow for [[transmission (telecommunications)|transmission]] distances of more than 100 km without amplification depending on the bit rate and modulation format used for transmission. A very advanced research topic within photonics is the investigation and fabrication of special structures and "materials" with engineered optical properties. These include [[photonic crystal]]s, [[photonic crystal fiber]]s and [[metamaterial]]s. [77] => [78] => ===Amplifiers=== [79] => {{Main|Optical amplifier}} [80] => Optical amplifiers are used to amplify an optical signal. Optical amplifiers used in optical communications are [[erbium-doped fiber amplifier]]s, [[semiconductor optical amplifier]]s, [[Raman amplifier]]s and [[optical parametric amplifier]]s. A very advanced research topic on optical amplifiers is the research on [[quantum dot]] semiconductor optical amplifiers. [81] => [82] => ===Detection=== [83] => [[Photodetector]]s detect light. Photodetectors range from very fast [[photodiode]]s for communications applications over medium speed charge coupled devices ([[Charge-coupled device|CCDs]]) for [[digital camera]]s to very slow [[solar cell]]s that are used for [[energy harvesting]] from [[sunlight]]. There are also many other photodetectors based on thermal, [[Photographic plate|chemical]], quantum, [[Photoelectric effect|photoelectric]] and other effects. [84] => [85] => ===Modulation=== [86] => {{main|Optical modulator}} [87] => Modulation of a light source is used to encode information on a light source. Modulation can be achieved by the light source directly. One of the simplest examples is to use a [[flashlight]] to send [[Morse code]]. Another method is to take the light from a light source and modulate it in an external [[optical modulator]].{{cite journal |last=Al-Tarawni |first=Musab A. M. |date=October 2017 |title=Improvement of integrated electric field sensor based on hybrid segmented slot waveguide |journal=Optical Engineering |volume=56 |issue=10 |pages=107105 |doi=10.1117/1.oe.56.10.107105|bibcode=2017OptEn..56j7105A |s2cid=125975031 }} [88] => [89] => An additional topic covered by modulation research is the modulation format. [[On-off keying]] has been the commonly used modulation format in optical communications. In the last years more advanced modulation formats like [[phase-shift keying]] or even [[orthogonal frequency-division multiplexing]] have been investigated to counteract effects like [[dispersion (optics)|dispersion]] that degrade the quality of the transmitted signal. [90] => [91] => ===Photonic systems=== [92] => Photonics also includes research on photonic systems. This term is often used for [[optical communication]] systems. This area of research focuses on the implementation of photonic systems like high speed photonic networks. This also includes research on [[optical regenerator]]s, which improve optical signal quality.{{citation needed|date=April 2013}} [93] => [94] => ===Photonic integrated circuits=== [95] => {{main|Photonic integrated circuit}} [96] => Photonic integrated circuits (PICs) are optically active integrated semiconductor photonic devices. The leading commercial application of PICs are optical transceivers for data center optical networks. PICs were fabricated on III-V [[indium phosphide]] semiconductor wafer substrates were the first to achieve commercial success;{{cite book|author1=Ivan Kaminow|author2=Tingye Li|author3=Alan E Willner|title=Optical Fiber Telecommunications Volume VIA: Components and Subsystems|url=https://books.google.com/books?id=8V8LMI9WhGEC|date=3 May 2013|publisher=Academic Press|isbn=978-0-12-397235-4}} PICs based on silicon wafer substrates are now also a commercialized technology. [97] => [98] => Key Applications for Integrated Photonics include: [99] => * Data Center Interconnects: Data centers continue to grow in scale as companies and institutions store and process more information in the cloud. With the increase in data center compute, the demands on data center networks correspondingly increase. Optical cables can support greater lane bandwidth at longer transmission distances than copper cables. For short-reach distances and up to 40 Gbit/s data transmission rates, non-integrated approaches such as [[vertical-cavity surface-emitting laser]]s can be used for optical transceivers on [[multi-mode optical fiber]] networks.{{cite book|author=Chang, Frank|title=Datacenter Connectivity Technologies: Principles and Practice|url=https://books.google.com/books?id=ooIstAEACAAJ|date=17 August 2018|publisher=River Publishers|isbn=978-87-93609-22-8}} Beyond this range and bandwidth, photonic integrated circuits are key to enable high-performance, low-cost optical transceivers. [100] => * Analog RF Signal Applications: Using the GHz precision signal processing of photonic integrated circuits, radiofrequency (RF) signals can be manipulated with high fidelity to add or drop multiple channels of radio, spread across an ultra-broadband frequency range. In addition, photonic integrated circuits can remove background noise from an RF signal with unprecedented precision, which will increase the signal to noise performance and make possible new benchmarks in low power performance. Taken together, this high precision processing enables us to now pack large amounts of information into ultra-long-distance radio communications. {{Citation needed|date=July 2018}} [101] => * Sensors: Photons can also be used to detect and differentiate the optical properties of materials. They can identify chemical or biochemical gases from air pollution, organic produce, and contaminants in the water. They can also be used to detect abnormalities in the blood, such as low glucose levels, and measure biometrics such as pulse rate. Photonic integrated circuits are being designed as comprehensive and ubiquitous sensors with glass/silicon, and embedded via high-volume production in various mobile devices. {{Citation needed|date=July 2018}} Mobile platform sensors are enabling us to more directly engage with practices that better protect the environment, monitor food supply and keep us healthy. [102] => * [[LIDAR]] and other [[phased array]] [[imaging]]: Arrays of PICs can take advantage of phase delays in the light reflected from objects with three-dimensional shapes to reconstruct 3D images, and Light Imaging, Detection and Ranging (LIDAR) with laser light can offer a complement to [[radar]] by providing precision imaging (with 3D information) at close distances. This new form of [[machine vision]] is having an immediate application in driverless cars to reduce collisions, and in biomedical imaging. Phased arrays can also be used for free-space communications and novel display technologies. Current versions of LIDAR predominantly rely on moving parts, making them large, slow, low resolution, costly, and prone to mechanical vibration and premature failure. Integrated photonics can realize LIDAR within a footprint the size of a postage stamp, scan without moving parts, and be produced in high volume at low cost. {{Citation needed|date=July 2018}} [103] => [104] => === Biophotonics === [105] => {{main|Biophotonics}} [106] => '''Biophotonics''' employs tools from the field of photonics to the study of [[biology]]. Biophotonics mainly focuses on improving medical diagnostic abilities (for example for cancer or infectious diseases){{Cite journal|last1=Lorenz|first1=Björn|last2=Wichmann|first2=Christina|last3=Stöckel|first3=Stephan|last4=Rösch|first4=Petra|last5=Popp|first5=Jürgen|date=May 2017|title=Cultivation-Free Raman Spectroscopic Investigations of Bacteria|journal=Trends in Microbiology|volume=25|issue=5|pages=413–424|doi=10.1016/j.tim.2017.01.002|issn=1878-4380|pmid=28188076}} but can also be used for environmental or other applications.{{Cite journal|last1=Wichmann|first1=Christina|last2=Chhallani|first2=Mehul|last3=Bocklitz|first3=Thomas|last4=Rösch|first4=Petra|last5=Popp|first5=Jürgen|date=5 November 2019|title=Simulation of Transportation and Storage and Their Influence on Raman Spectra of Bacteria|journal=Analytical Chemistry|volume=91|issue=21|pages=13688–13694|doi=10.1021/acs.analchem.9b02932|issn=1520-6882|pmid=31592643|s2cid=203924741 }}{{Cite journal|last1=Taubert|first1=Martin|last2=Stöckel|first2=Stephan|last3=Geesink|first3=Patricia|last4=Girnus|first4=Sophie|last5=Jehmlich|first5=Nico|last6=von Bergen|first6=Martin|last7=Rösch|first7=Petra|last8=Popp|first8=Jürgen|last9=Küsel|first9=Kirsten|date=January 2018|title=Tracking active groundwater microbes with D2 O labelling to understand their ecosystem function|journal=Environmental Microbiology|volume=20|issue=1|pages=369–384|doi=10.1111/1462-2920.14010|issn=1462-2920|pmid=29194923|s2cid=25510308}} The main advantages of this approach are speed of analysis, [[Non-invasive procedure|non-invasive]] diagnostics, and the ability to work [[In situ|in-situ]]. [107] => [108] => ==See also== [109] => * [[Nano-optics]] [110] => * [[OP-TEC]] [111] => * [[Optronics]]/optoelectronics [112] => * [[Organic photonics]] [113] => * [[Bio-inspired photonics]] [114] => * [[Photonics mast]] (on submarines) [115] => * [[Photonic radar]] [116] => * [[European Photonics Industry Consortium]] [117] => * [[IOWN Global Forum]] [118] => [119] => ==References== [120] => {{reflist}} [121] => [122] => [124] => {{Prone to spam|date=March 2015}} [125] => [140] => [141] => {{Engineering fields}} [142] => {{Branches of physics}} [143] => {{Photonics}} [144] => [145] => {{Authority control}} [146] => [147] => [[Category:Photonics| ]] [148] => [[Category:Optics]] [] => )
good wiki

Photonics

Photonics is a branch of optics that involves the application of generation, detection, and manipulation of light in form of photons through emission, transmission, modulation, signal processing, switching, amplification, and sensing. Photonics is closely related to quantum electronics, where quantum electronics deals with the theoretical part of it while photonics deal with its engineering applications.

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