Emil Wolf (July 30, 1922 – June 2, 2018) was a Czech-born American

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

who made advancements in physical

optics Optics is the branch of physics that studies the behaviour and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behaviour of visible, ultrav ...

, including

diffraction Diffraction is defined as the interference or bending of waves around the corners of an obstacle or through an aperture into the region of geometrical shadow of the obstacle/aperture. The diffracting object or aperture effectively becomes a s ...

coherence Coherence, coherency, or coherent may refer to the following: Physics * Coherence (physics), an ideal property of waves that enables stationary (i.e. temporally and spatially constant) interference * Coherence (units of measurement), a deriv ...

properties of optical fields,

spectroscopy Spectroscopy is the field of study that measures and interprets the electromagnetic spectra that result from the interaction between electromagnetic radiation and matter as a function of the wavelength or frequency of the radiation. Matter ...

of partially coherent

radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...

, and the theory of direct scattering and inverse scattering. He was also the author of numerous other contributions to optics.

Life and career

Wolf was born into a Jewish family in

Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 million people. The city has a temperate ...

Czechoslovakia , rue, Чеськословеньско, , yi, טשעכאסלאוואקיי, , common_name = Czechoslovakia , life_span = 1918–19391945–1992 , p1 = Austria-Hungary , image_p1 ...

. He was forced to leave his native country when the Germans invaded. After brief periods in Italy and France (where he worked for the Czech government in exile), he moved to the United Kingdom in 1940. He received his B.Sc. in Mathematics and Physics (1945), and Ph.D. in Mathematics from

Bristol University , mottoeng = earningpromotes one's innate power (from Horace, ''Ode 4.4'') , established = 1595 – Merchant Venturers School1876 – University College, Bristol1909 – received royal charter , type ...

, England, in 1948. Between 1951 and 1954 he worked at the

University of Edinburgh The University of Edinburgh ( sco, University o Edinburgh, gd, Oilthigh Dhùn Èideann; abbreviated as ''Edin.'' in post-nominals) is a public research university based in Edinburgh, Scotland. Granted a royal charter by King James VI in 1 ...

with

Max Born Max Born (; 11 December 1882 – 5 January 1970) was a German physicist and mathematician who was instrumental in the development of quantum mechanics. He also made contributions to solid-state physics and optics and supervised the work of a ...

, writing the famous textbook

Principles of Optics ''Principles of Optics'', colloquially known as ''Born and Wolf'', is an optics textbook written by Max Born and Emil Wolf that was initially published in 1959 by Pergamon Press. After going through six editions with Pergamon Press, the book ...

now usually known simply as '' Born and Wolf''. After a period on the Faculty of the University of Manchester, he moved to the United States in 1959 to take a position at the

University of Rochester The University of Rochester (U of R, UR, or U of Rochester) is a private research university in Rochester, New York. The university grants undergraduate and graduate degrees, including doctoral and professional degrees. The University of ...

. He became a naturalized U.S. citizen and was the Wilson Professor of Optical Physics at the University of Rochester. He was president of the

Optical Society of America Optica (formerly known as The Optical Society (OSA) and before that as the Optical Society of America) is a professional society of individuals and companies with an interest in optics and photonics. It publishes journals and organizes conference ...

in 1978. Until his death Wolf resided in Cloverwood in Pittsford, New York, with his wife. Wolf predicted a new mechanism that produces

redshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase in fr ...

and

blueshift In physics, a redshift is an increase in the wavelength, and corresponding decrease in the frequency and photon energy, of electromagnetic radiation (such as light). The opposite change, a decrease in wavelength and simultaneous increase i ...

, that is not due to moving sources (

Doppler effect The Doppler effect or Doppler shift (or simply Doppler, when in context) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who ...

), that has subsequently been confirmed experimentally (called the Wolf effect). Technically, he found that two non- Lambertian sources that emit beamed energy, can interact in a way that causes a shift in the spectral lines. It is analogous to a pair of tuning forks with similar frequencies (pitches), connected together mechanically with a sounding board; there is a strong coupling that results in the resonant frequencies getting "dragged down" in pitch. The Wolf effect can produce either redshifts or blueshifts, depending on the observer's point of view, but is redshifted when the observer is head-on. A subsequent 1999 article by Sisir Roy ''et al.'' have suggested that the Wolf effect may explain discordant redshift in certain quasars. Wolf remained an active teacher, researcher and author well into his 80s. He died on June 2, 2018, aged 95.

Works

Wolf was a very well known book author in the field of optics. Along with

, he co-wrote ''

'' one of the standard textbooks of optics commonly known as "Born and Wolf". In addition he co-authored, with Leonard Mandel, ''Optical Coherence and Quantum Optics''. He also authored ''Introduction to the Theory of Coherence and Polarization of Light'' and ''Selected Works of Emil Wolf with Commentary'' (World Scientific Publishing, 2001, ). Furthermore, he edited the '' Progress in Optics'' series of books, for

Elsevier Elsevier () is a Dutch academic publishing company specializing in scientific, technical, and medical content. Its products include journals such as '' The Lancet'', '' Cell'', the ScienceDirect collection of electronic journals, '' Trends'', ...

, from its inception in 1962.

Awards, memberships and degrees

Awards

* Frederic Ives Medal of the

(1977) * Albert A. Michelson Medal of the

Franklin Institute The Franklin Institute is a science museum and the center of science education and research in Philadelphia, Pennsylvania. It is named after the American scientist and statesman Benjamin Franklin. It houses the Benjamin Franklin National Memori ...

(1980) * Max Born Award of the Optical Society of America (1987) *Marconi Medal of the Italian National Research Council (1987) *Gold Medal of the Czechoslovak Academy of Science (1991) *Medal of the Union of Czechoslovak Mathematicians and Physicists (1991) *Gold Medal of Palacký University of Olomouc, Czechoslovakia (1991) *

Esther Hoffman Beller Medal The Esther Beller Hoffman Medal is an award given by The Optical Society that recognizes outstanding contributions by individuals around the world to the fields of optical science and engineering education. The award was established in 1993 and pas ...

(2002) * G. G. Stokes Award of

SPIE SPIE (formerly the Society of Photographic Instrumentation Engineers, later the Society of Photo-Optical Instrumentation Engineers) is an international not-for-profit professional society for optics and photonics technology, founded in 1955. It ...

(2010)

Memberships

*Honorary member of the Optical Society of America (President in 1978) *Honorary member of the Optical Societies of India and Australia

Honorary degrees

University of Groningen The University of Groningen (abbreviated as UG; nl, Rijksuniversiteit Groningen, abbreviated as RUG) is a public research university of more than 30,000 students in the city of Groningen in the Netherlands. Founded in 1614, the university is th ...

, the Netherlands (1989) *

(1990) * Palacký University of Olomouc (1992) *

University of Bristol , mottoeng = earningpromotes one's innate power (from Horace, ''Ode 4.4'') , established = 1595 – Merchant Venturers School1876 – University College, Bristol1909 – received royal charter , type ...

(1997) *

Université Laval Université Laval is a public research university in Quebec City, Quebec, Canada. The university was founded by royal charter issued by Queen Victoria in 1852, with roots in the founding of the Séminaire de Québec in 1663 by François de Montm ...

, Quebec (1997) *

University of Franche-Comté The University of Franche-Comté (UFC) is a pluridisciplinary public French university located in Besançon, Franche-Comté, with decentralized campuses in Belfort, Montbéliard, Vesoul and Lons-le-Saunier. It is a founding member of the comm ...

, France (1999) * Aalborg University, Denmark (1999).

References

External links

Emil Wolf
Home Page at

.
''Principles of Optics: Electromagnetic Theory of Propagation, Interference and Diffraction of Light (English)''
Sample chapters. *
Articles Published by early OSA Presidents
Journal of the Optical Society of America * Gregory J. Gbur (2018
RIP Emil Wolf, 1922-2018)
{{DEFAULTSORT:Wolf, Emil 1922 births 2018 deaths American physicists Optical physicists Fellows of Optica (society) Czechoslovak emigrants to the United Kingdom Czechoslovak emigrants to the United States Czech Jews Scientists from Prague Alumni of the University of Bristol University of Rochester faculty Presidents of Optica (society) People with acquired American citizenship Jews who immigrated to the United Kingdom to escape Nazism