Francisco Javier "Frank" Duarte (born c. 1954) is a
laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The fir ...
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 caus ...
and
author
An author is the writer of a book, article, play, mostly written work. A broader definition of the word "author" states:
"''An author is "the person who originated or gave existence to anything" and whose authorship determines responsibility f ...
/editor of several books on
tunable laser
A tunable laser is a laser whose wavelength of operation can be altered in a controlled manner. While all laser gain media allow small shifts in output wavelength, only a few types of lasers allow continuous tuning over a significant wavelength ran ...
s.
His research on
physical optics
In physics, physical optics, or wave optics, is the branch of optics that studies interference, diffraction, polarization, and other phenomena for which the ray approximation of geometric optics is not valid. This usage tends not to include effec ...
and laser development has won several awards, including an
Engineering Excellence Award in 1995 for the invention of the
N-slit laser interferometer.
Research
Laser oscillators
Duarte and Piper introduced ''multiple-prism near-grazing-incidence grating'' cavities which originally were disclosed as
copper-laser-pumped narrow-linewidth tunable laser oscillators.
Subsequently, he developed narrow-linewidth multiple-prism grating configurations for high-power CO
2 laser oscillators and solid-state tunable organic laser oscillators.
Intracavity dispersion theory
Duarte also conceived the
multiple-prism dispersion theories for
tunable narrow-linewidth laser oscillators,
and multiple-prism laser
pulse compression Pulse compression is a signal processing technique commonly used by radar, sonar and echography to increase the range resolution as well as the signal to noise ratio. This is achieved by modulating the transmitted pulse and then correlating th ...
,
which are summarized in several of his books.
The introduction to this theory is the generalized multiple-prism dispersion equation
:
which has found a variety of applications.
Tunable lasers for isotope separation
His
tunable narrow-linewidth laser oscillator configurations
have been adopted by various research groups working on
uranium
Uranium is a chemical element with the symbol U and atomic number 92. It is a silvery-grey metal in the actinide series of the periodic table. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons. Uranium is weak ...
atomic vapor laser isotope separation
Atomic vapor laser isotope separation, or AVLIS, is a method by which specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions. A similar technology, using molecules instead of atoms, is ...
(AVLIS).
This work was supported by the
Australian Atomic Energy Commission
The Australian Atomic Energy Commission (AAEC) was a statutory body of the Australian government.
It was established in 1952, replacing the Atomic Energy Policy Committee. In 1981 parts of the Commission were split off to become part of CSIRO, t ...
.
During the course of this research, Duarte writes that he did approach the then federal minister for energy,
Sir John Carrick, to advocate for the introduction of an
AVLIS
Atomic vapor laser isotope separation, or AVLIS, is a method by which specially tuned lasers are used to separate isotopes of uranium using selective ionization of hyperfine transitions. A similar technology, using molecules instead of atoms, is ...
facility in Australia. In 2002, he participated in research that led to the isotope separation of
lithium
Lithium (from el, λίθος, lithos, lit=stone) is a chemical element with the symbol Li and atomic number 3. It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid el ...
using narrow-linewidth tunable
diode lasers.
Solid state organic dye lasers
From the mid-1980s to early 1990s Duarte and scientists from the
US
Army Missile Command developed ''ruggedized''
narrow-linewidth laser oscillators tunable directly in the visible spectrum.
This constituted the first disclosure, in the open literature, of a tunable narrow-linewidth laser tested on a rugged terrain. This research led to experimentation with polymer gain media and in 1994 Duarte reported on the first narrow-linewidth tunable
solid state dye laser oscillators.
These dispersive oscillator architectures were then refined to yield single-longitudinal-mode emission limited only by
Heisenberg's uncertainty principle
In quantum mechanics, the uncertainty principle (also known as Heisenberg's uncertainty principle) is any of a variety of mathematical inequalities asserting a fundamental limit to the accuracy with which the values for certain pairs of physic ...
.
Organic gain media
Joint research, with R. O. James, on solid-state organic-inorganic materials, led to the discovery of polymer-
nanoparticle
A nanoparticle or ultrafine particle is usually defined as a particle of matter that is between 1 and 100 nanometres (nm) in diameter. The term is sometimes used for larger particles, up to 500 nm, or fibers and tubes that are less than 1 ...
gain media and to the emission of tunable low-divergence homogeneous laser beams from this class of media.
In 2005, Duarte and colleagues were the first to demonstrate directional coherent emission from an electrically excited
organic semiconductor
Organic semiconductors are solids whose building blocks are pi-bonded molecules or polymers made up by carbon and hydrogen atoms and – at times – heteroatoms such as nitrogen, sulfur and oxygen. They exist in the form of molecular crystals or ...
.
These experiments utilized a tandem
OLED
An organic light-emitting diode (OLED or organic LED), also known as organic electroluminescent (organic EL) diode, is a light-emitting diode (LED) in which the emissive electroluminescent layer is a film of organic compound that emits light i ...
within an integrated interferometric configuration.
[
Duarte's work in this area began with the demonstration of narrow-linewidth laser emission using ]coumarin
Coumarin () or 2''H''-chromen-2-one is an aromatic organic chemical compound with formula . Its molecule can be described as a benzene molecule with two adjacent hydrogen atoms replaced by a lactone-like chain , forming a second six-membered h ...
-tetramethyl dyes which offer high conversion efficiency and wide tunability in the green region of the electromagnetic spectrum.
Interferometry and quantum optics
In the late 1980s, he invented the digital ''N''-slit laser interferometer for applications in imaging and microscopy
Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of micr ...
. Concurrently, he applied Dirac’s notation to describe quantum mechanically its interferometric and propagation characteristics. A further innovation in this interferometer was the use of extremely elongated Gaussian beams, width to height ratios of up to 2000:1, for
sample illumination.
This research also led to the generalized N-slit interferometric equation
Quantum mechanics was first applied to optics, and interference in particular, by Paul Dirac. Richard Feynman, in his Lectures on Physics, uses Dirac's notation to describe thought experiments on double-slit interference of electrons. Feynman's ...
that was then applied to describe classical optics phenomena such as interference
Interference is the act of interfering, invading, or poaching. Interference may also refer to:
Communications
* Interference (communication), anything which alters, modifies, or disrupts a message
* Adjacent-channel interference, caused by extr ...
, 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 ...
, refraction
In physics, refraction is the redirection of a wave as it passes from one medium to another. The redirection can be caused by the wave's change in speed or by a change in the medium. Refraction of light is the most commonly observed phenomeno ...
, and reflection Reflection or reflexion may refer to:
Science and technology
* Reflection (physics), a common wave phenomenon
** Specular reflection, reflection from a smooth surface
*** Mirror image, a reflection in a mirror or in water
** Signal reflection, in ...
, in a generalized and unified quantum approach that includes positive and negative refraction. He also derived the cavity linewidth equation, for dispersive laser oscillators, using quantum mechanical principles.
Further developments include very large ''N''-slit laser interferometers to generate and propagate interferometric characters for secure free-space optical communications. ''Interferometric characters'' is a term coined in 2002 to link interefometric signals to alphanumerical characters (see figure's legend).
These experiments provided the first observation of diffraction patterns superimposed over propagating interference signals, thus demonstrating non-destructive (or soft) interception of propagating interferograms.
A spin-off of this research, with applications to the aviation industry, resulted from the discovery that ''N''-slit laser interferometers are very sensitive detectors of clear air turbulence
In meteorology, clear-air turbulence (CAT) is the turbulent movement of air masses in the absence of any visual clues, such as clouds, and is caused when bodies of air moving at widely different speeds meet.
The atmospheric region most suscepti ...
.
Duarte provides a description of quantum optics, almost entirely via Dirac's notation, in his book ''Quantum Optics for Engineers''. In this book he derives the probability amplitude for quantum entanglement,
:
which he calls the Pryce-Ward
Ward may refer to:
Division or unit
* Hospital ward, a hospital division, floor, or room set aside for a particular class or group of patients, for example the psychiatric ward
* Prison ward, a division of a penal institution such as a pris ...
probability amplitude, from an ''N''-slit interferometric perspective. It is this that becomes the probability disclosed by Pryce and Ward. Duarte also emphasizes a pragmatic non-interpretational approach to quantum mechanics.
Career
Macquarie University
At Macquarie University
Macquarie University ( ) is a public research university based in Sydney, Australia, in the suburb of Macquarie Park. Founded in 1964 by the New South Wales Government, it was the third university to be established in the metropolitan area of S ...
, Duarte studied quantum physics under John Clive Ward
John Clive Ward, (1 August 1924 – 6 May 2000) was a British-Australian physicist. He introduced the Ward–Takahashi identity, also known as "Ward Identity" (or "Ward's Identities"). Andrei Sakharov said Ward was one of the titans of q ...
and semiconductor physics under Ronald Ernest Aitchison. His PhD research was on laser physics and his supervisor was James A. Piper.
In the area of university politics, he established and led the Macquarie science reform movement
Macquarie science reform movement refers to the successful
transformation of the degree system at Macquarie University in 1979
which followed an academic and political campaign initiated in 1977.F. J. Duarte, M. Golding, and B. Bulliman, Science ...
, that transformed the degree structure of the university. Macquarie's science reform, was widely supported by local scientists including physicists R. E. Aitchison, R. E. B. Makinson, A. W. Pryor
Arthur William Pryor (31 August 1928 – 6 September 2014) was an Australian physicist known for his contributions to neutron diffraction and infrared laser isotope separation.- A. W. Pryor, Personal memories of two advanced uranium enrichment p ...
, and J. C. Ward.
In 1980, Duarte was elected as one of the Macquarie representatives to the Australian Union of Students
The Australian Union of Students (AUS), formerly National Union of Australian University Students (NUAUS), was a representative body and lobby group for Australian university and college of advanced education students. It collapsed in 1984 and w ...
from where he was expelled, and then reinstated, for "running over the tables."
Following completion of his PhD work, Duarte did post doctoral research, with B. J. Orr at the University of New South Wales
The University of New South Wales (UNSW), also known as UNSW Sydney, is a public research university based in Sydney, New South Wales, Australia. It is one of the founding members of Group of Eight, a coalition of Australian research-intensive ...
, and then back at Macquarie University
Macquarie University ( ) is a public research university based in Sydney, Australia, in the suburb of Macquarie Park. Founded in 1964 by the New South Wales Government, it was the third university to be established in the metropolitan area of S ...
.
American phase
In 1983, Duarte traveled to the United States to assume a physics professorship at the University of Alabama
The University of Alabama (informally known as Alabama, UA, or Bama) is a Public university, public research university in Tuscaloosa, Alabama. Established in 1820 and opened to students in 1831, the University of Alabama is the oldest and la ...
. In 1985 he joined the Imaging Research Laboratories, at the Eastman Kodak Company
The Eastman Kodak Company (referred to simply as Kodak ) is an American public company that produces various products related to its historic basis in analogue photography. The company is headquartered in Rochester, New York, and is incorpor ...
, where he remained until 2006. While at Kodak he was chairman of Lasers '87 and subsequent conferences in this series. Duarte has had a long association with the US Army Missile Command and the US Army Aviation and Missile Command, where he has participated (with R. W. Conrad and T. S. Taylor) in directed energy research.
He was elected Fellow of the Australian Institute of Physics
The Australian Institute of Physics was established in 1963, when it replaced the Australian Branch of the British Institute of Physics based in London. in 1987) and a Fellow of the Optical Society of America in 1993.
In 1995, he received the Engineering Excellence Award for "the invention of an electrooptic coherent interferometer for direct applications to imaging diagnostics of transparent surfaces, such as photographic film and film substrates. and in 2016, he was awarded the
David Richardson Medal
' for "seminal contributions to the physics and technology of multiple-prism arrays for narrow-linewidth tunable laser oscillators and laser pulse compression," from the Optical Society.
Personal
Duarte was born in Santiago, Chile
Santiago (, ; ), also known as Santiago de Chile, is the capital (political), capital and largest city of Chile as well as one of the largest cities in the Americas. It is the center of Chile's most densely populated Regions of Chile, region, t ...
, and traveled to Sydney, Australia
Sydney ( ) is the capital city of the States and territories of Australia, state of New South Wales, and the most populous city in both Australia and List of cities in Oceania by population, Oceania. Located on Australia's east coast, the metro ...
, as a teenager. There, he lived first in Strathfield
Strathfield is a suburb in the Inner West of Sydney, in the state of New South Wales, Australia. It is located 12 kilometres west of the Sydney central business district and is the administrative centre of the Municipality of Strathfield. A ...
and then in the northern small town of Cowan
Cowan or Cowans may refer to:
Places Australia
* Cowan, New South Wales
* Cowan Creek, a waterway to the north of Sydney, Australia
* Division of Cowan, a federal division of the Australian House of Representatives, in Western Australia
* Hundr ...
. In the United States he resided for a brief period in Tuscaloosa, Alabama
Tuscaloosa ( ) is a city in and the seat of Tuscaloosa County in west-central Alabama, United States, on the Black Warrior River where the Gulf Coastal and Piedmont plains meet. Alabama's fifth-largest city, it had an estimated population of 1 ...
, and then moved to Western New York
Western New York (WNY) is the westernmost region of the U.S. state of New York. The eastern boundary of the region is not consistently defined by state agencies or those who call themselves "Western New Yorkers". Almost all sources agree WNY in ...
.
Books
* ''Dye Laser Principles'' (1990)[
]
* ''Tunable Laser Optics, 2nd Ed.'' (2015, Second edition)
*''Tunable Laser Applications, 3rd Ed'' (1996, 2009, 2016)
* ''Fundamentals of Quantum Entanglement'' (2019)
* ''Quantum Entanglement Engineering and Applications'' (2021)
See also
*Heat equation
In mathematics and physics, the heat equation is a certain partial differential equation. Solutions of the heat equation are sometimes known as caloric functions. The theory of the heat equation was first developed by Joseph Fourier in 1822 for t ...
*Laser space communication
Laser communication in space is the use of free-space optical communication in outer space. Communication may be fully in space (an inter-satellite laser link) or in a ground-to-satellite or satellite-to-ground application. The main advantage ...
s
* Multiple-prism beam expanders
*Organic laser
Organic lasers use an organic (carbon based) material as the gain medium. The first organic laser was the liquid dye laser. These lasers use laser dye solutions as their gain media.
Organic lasers are inherently tunable and when configured as ...
*Polarization rotator
A polarization rotator is an optical device that rotates the polarization axis of a linearly polarized light beam by an angle of choice. Such devices can be based on the Faraday effect, on birefringence, or on total internal reflection. F. J. ...
References
External links
Duarte's home page
at ''Lasers'' '92: right to left; Marlan Scully
Marlan Orvil Scully (born August 3, 1939) is an American physicist best known for his work in theoretical quantum optics. He is a professor at Texas A&M University and Princeton University. Additionally, in 2012 he developed a lab at the Baylor ...
, Willis Lamb
Willis Eugene Lamb Jr. (; July 12, 1913 – May 15, 2008) was an American physicist who won the Nobel Prize in Physics in 1955 "for his discoveries concerning the fine structure of the hydrogen spectrum." The Nobel Committee that year awarded hal ...
, John L. Hall
John Lewis "Jan" Hall (born August 21, 1934) is an American physicist, and Nobel laureate in physics. He shared the 2005 Nobel Prize in Physics with Theodor W. Hänsch and Roy Glauber for his work in precision spectroscopy.
Biography
Born ...
, and F. J. Duarte
{{DEFAULTSORT:Duarte, F. J.
21st-century American physicists
American inventors
Experimental physicists
Quantum physicists
Laser researchers
Scientific instrument makers
American nanotechnologists
Microscopists
Futurologists
Space advocates
Fellows of Optica (society)
Fellows of the Australian Institute of Physics
American science writers
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20th-century American male writers
21st-century American male writers
American male essayists
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American book publishers (people)
21st-century American businesspeople
Kodak people
Macquarie University alumni
Instituto Nacional General José Miguel Carrera alumni
American people of Spanish descent
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People from Santiago
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Chilean physicists
Living people
1950s births
Hispanic and Latino American scientists
Hispanic and Latino American physicists