Rodney Loudon (25 July 1934 – 25 December 2022) was a British physicist, best known for his work in

quantum optics Quantum optics is a branch of atomic, molecular, and optical physics and quantum chemistry that studies the behavior of photons (individual quanta of light). It includes the study of the particle-like properties of photons and their interaction ...

. He was Emeritus Professor of Theoretical Physics at the

University of Essex The University of Essex is a public university, public research university in Essex, England. Established by royal charter in 1965, it is one of the original plate glass university, plate glass universities. The university comprises three camp ...

.Staff profile
University of Essex, retrieved 2016-03-14. Loudon died on 25 December 2022, at the age of 88.

Education

Loudon attended the

Bury Grammar School Bury Grammar School is a 3–18 private day school for boys in Bury, Greater Manchester, England, that has existed since c.1570. It is now part of a group of schools for preschool, junior, senior and sixth form studies. Since 2017, when Bu ...

Manchester Manchester () is a city and the metropolitan borough of Greater Manchester, England. It had an estimated population of in . Greater Manchester is the third-most populous metropolitan area in the United Kingdom, with a population of 2.92&nbs ...

. He received his

Master of Arts A Master of Arts ( or ''Artium Magister''; abbreviated MA or AM) is the holder of a master's degree awarded by universities in many countries. The degree is usually contrasted with that of Master of Science. Those admitted to the degree have ...

(1956) and

Doctor of Philosophy A Doctor of Philosophy (PhD, DPhil; or ) is a terminal degree that usually denotes the highest level of academic achievement in a given discipline and is awarded following a course of Postgraduate education, graduate study and original resear ...

(1959) degrees from the

University of Oxford The University of Oxford is a collegiate university, collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the List of oldest un ...

, where he was a member of the

Brasenose College Brasenose College (BNC) is one of the constituent colleges of the University of Oxford in the United Kingdom. It began as Brasenose Hall in the 13th century, before being founded as a college in 1509. The library and chapel were added in the m ...

.After Oxford he undertook postdoctoral research at

University of California, Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a Public university, public Land-grant university, land-grant research university in Berkeley, California, United States. Founded in 1868 and named after t ...

Research work

Loudon's research focused on various aspects of theoretical solid state and

laser physics Laser science or laser physics is a branch of optics that describes the theory and practice of lasers. Laser science is principally concerned with quantum electronics, laser construction, optical cavity design, the physics of producing a po ...

, and particularly on

light scattering In physics, scattering is a wide range of physical processes where moving particles or radiation of some form, such as light or sound, are forced to deviate from a straight trajectory by localized non-uniformities (including particles and radia ...

. His 1964 paper on the

Raman effect In chemistry and physics, Raman scattering or the Raman effect () is the inelastic scattering of photons by matter, meaning that there is both an exchange of energy and a change in the light's direction. Typically this effect involves vibrationa ...

was one of the 100 most cited papers in all areas of physical science between 1960 and 1969. He has published more than 190 papers and 3 books, one of which (the three editions of ''The Quantum Theory of Light'') is recognized internationally and has been translated into Russian and Japanese. His early work on

exciton An exciton is a bound state of an electron and an electron hole which are attracted to each other by the electrostatic Coulomb's law, Coulomb force resulting from their opposite charges. It is an electrically neutral quasiparticle regarded as ...

phonon A phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, specifically in solids and some liquids. In the context of optically trapped objects, the quantized vibration mode can be defined a ...

s and

magnon A magnon is a quasiparticle, a collective excitation of the spin structure of an electron in a crystal lattice. In the equivalent wave picture of quantum mechanics, a magnon can be viewed as a quantized spin wave. Magnons carry a fixed amou ...

s and his later treatments of non-classical effects in the statistical properties of

light Light, visible light, or visible radiation is electromagnetic radiation that can be visual perception, perceived by the human eye. Visible light spans the visible spectrum and is usually defined as having wavelengths in the range of 400– ...

have attracted many citations. His later work on surface excitations and on

optical amplification An optical amplifier is a device that amplifies an optical signal directly, without the need to first convert it to an electrical signal. An optical amplifier may be thought of as a laser without an optical cavity, or one in which feedback from ...

attenuation In physics, attenuation (in some contexts, extinction) is the gradual loss of flux intensity through a Transmission medium, medium. For instance, dark glasses attenuate sunlight, lead attenuates X-rays, and water and air attenuate both light and ...

and detection has also proved to be important. Loudon worked at the University of Essex as Professor, Chairman and Dean. He has also worked at

British Telecom BT Group plc (formerly British Telecom) is a British Multinational corporation, multinational telecommunications holding company headquartered in London, England. It has operations in around 180 countries and is the largest provider of fixed-li ...

Royal Radar Establishment The Royal Radar Establishment was a research centre in Malvern, Worcestershire in the United Kingdom. It was formed in 1953 as the Radar Research Establishment by the merger of the Air Ministry's Telecommunications Research Establishment (TRE ...

Bell Telephone Laboratories Nokia Bell Labs, commonly referred to as ''Bell Labs'', is an American industrial research and development company owned by Finnish technology company Nokia. With headquarters located in Murray Hill, New Jersey, Murray Hill, New Jersey, the compa ...

and

Radio Corporation of America RCA Corporation was a major American electronics company, which was founded in 1919 as the Radio Corporation of America. It was initially a patent pool, patent trust owned by General Electric (GE), Westinghouse Electric Corporation, Westinghou ...

, and he has been a consultant to these organisations over several years, contributing to both applied and fundamental research. In addition to his physics research Loudon was a member of

Institute of Physics The Institute of Physics (IOP) is a UK-based not-for-profit learned society and professional body that works to advance physics education, physics research, research and applied physics, application. It was founded in 1874 and has a worldwide ...

Council and Opto-Electronics Group of

Rank Prizes The Rank Prizes comprise the Rank Prize for Optoelectronics and the Rank Prize for Nutrition. The prizes recognise, reward and encourage researchers working in the respective fields of optoelectronics and nutrition. The prizes are funded by the c ...

Committee.

Books

The Quantum Theory of Light
(1973); 2nd edition (1983)
3rd edition (2000)
* with William Hayes
Scattering of Light by Crystals
(1978) * with David J. Barber
An Introduction to the Properties of Condensed Matter
(1989)

Awards and honours

*Loudon was elected a Fellow of the Royal Society (FRS) in 1987. One or more of the preceding sentences may incorporate text from the royalsociety.org website where "all text published under the heading 'Biography' on Fellow profile pages is available under Creative Commons Attribution 4.0 International License." *

Young Medal and Prize The Institute of Physics (IOP) awards numerous prizes to acknowledge contributions to physics research, education and applications. It also offers smaller specific subject-group prizes, such as for PhD thesis submissions. Bilateral awards * The ...

1987 *

Max Born Award The Max Born Award is given by Optica (formerly the Optical Society of America) for ''outstanding contributions to physical optics'' and is named after Max Born, a physicist renowned for his foundational contributions to quantum mechanics and opt ...

1992. *

Humboldt Prize The Humboldt Research Award (), also known informally as the Humboldt Prize, is an award given by the Alexander von Humboldt Foundation of Germany to internationally renowned scientists and scholars who work outside of Germany in recognition of ...

1998.

References

{{DEFAULTSORT:Loudon, Rodney 1934 births 2022 deaths British physicists Fellows of the Royal Society Alumni of Brasenose College, Oxford Academics of the University of Essex People from Prestwich