F. J. Duarte
Encyclopedia
F. J. Duarte is a laser
physicist and author/editor of several well-known books on tunable laser
s. He introduced the generalized multiple-prism dispersion theory
and has discovered various multiple-prism grating oscillator laser configurations. These configurations include the multiple-prism near-grazing-incidence grating cavities originally disclosed as copper-laser
-pumped narrow-linewidth tunable lasers. Duarte's contributions have found applications in a variety of fields including:
Army Missile Command
developed, and demonstrated, ruggedized narrow-linewidth laser oscillators tunable directly in the visible spectrum. This pioneering work 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
. His work on solid-state organic-inorganic materials led to the assessment of intra-gain-medium interference
phenomena and to the emission of low-divergence homogeneous laser beams from polymer-nanoparticle
gain media. In 2005 Duarte and colleagues were the first to demonstrate coherent emission from an electrically excited organic semiconductor
.
atomic vapor laser isotope separation (AVLIS). This work was supported by the Australian Atomic Energy Commission
. In a review article, Duarte discloses that during the course of this research he did approach the then federal minister for energy, Sir John L. Carrick
, to advocate for the introduction of an AVLIS facility in Australia. In 2002, he participated in research that led to the isotope separation of lithium
using tunable diode lasers.
and to solve problems in industrial imaging and optical metrology. The electro-optical N-slit interferometer uses prismatic beam expansion
to illuminate the N-slit array and comprises a photodiode array (or digital detector), at the interference plane, to register the interferograms. This work also led to a generalized N-slit interferometric equation
that was then applied to describe interference, diffraction
, refraction
, and reflection
, in a rational and unified approach.
More recently, Duarte and colleagues have developed very large N-slit laser interferometers to generate and propagate interferometric characters for secure free-space optical communications
. These experiments have also provided the first observation of diffraction patterns superimposed over propagating interference signals.
(Sydney, Australia) where he also established and led the successful science reform movement
of the late 1970s. Science reform, at Macquarie, was widely supported by local scientists including physicists Ronald Ernest Aitchison
, R. E. B. Makinson, and the famed John Clive Ward
. His career path includes post-doctoral research in Australia, plus academic and industrial-research appointments in the United States
.
of the Optical Society of America (1993) for his contributions to the development of narrow-linewidth
tunable lasers
. He is the first South American to have received such distinctions. Subsequently, he received the prestigious Engineering Excellence Award from the Optical Society of America for the invention of the N-slit laser interferometer
. Duarte's contributions are cited in well over a hundred scholarly books, including several classics.
Laser
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of photons. The term "laser" originated as an acronym for Light Amplification by Stimulated Emission of Radiation...
physicist and author/editor of several well-known books on tunable laser
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 range....
s. He introduced the generalized multiple-prism dispersion theory
Multiple-prism dispersion theory
The first description of multiple-prism arrays, and multiple-prism dispersion, was given by Newton in his book Opticks. Prism pair expanders were introduced by Brewster in 1813. A modern mathematical description of the single-prism dispersion was given by Born and Wolf in 1959...
and has discovered various multiple-prism grating oscillator laser configurations. These configurations include the multiple-prism near-grazing-incidence grating cavities originally disclosed as copper-laser
Copper vapor laser
Copper vapor laser uses vapors of copper as the lasing medium in a 3-level laser. It produces green laser light at 510.6 nm and yellow laser light at 578.2 nm. The pulse width is typically from 5 to 60 ns, and peak power from 50 to 5000 kW. Its pulse repetition frequencies can be 2 to 100 kHz...
-pumped narrow-linewidth tunable lasers. Duarte's contributions have found applications in a variety of fields including:
- atomic vapor laser isotope separation,
- laser medicineLaser medicineLaser medicine is the use of various types of lasers in medical diagnosis, treatment, or therapy. Types of lasers used in medicine include in principle any laser design, especially:* CO2 lasers* diode lasers* dye lasers* excimer lasers* fiber lasers...
, - laser microscopyMicroscopyMicroscopy is the technical field of using microscopes to view samples and objects that cannot be seen with the unaided eye...
, - laser pulse compressionPrism compressorA prism compressor is an optical device used to shorten the duration of a positively chirped ultrashort laser pulse by giving different wavelength components a different time delay. It typically consists of two prisms and a mirror. Figure 1 shows the construction of such a compressor...
, - laser spectroscopy,
- tunable diode lasers.
Solid state dye laser development
From the mid 1980s to early 1990s Duarte and scientists from the USArmy Missile Command
United States Army Aviation and Missile Command
The United States Army Aviation and Missile Command is primarily responsible for life cycle management of army missile, helicopter, unmanned ground vehicle and unmanned aerial vehicle weapon systems. The central part of AMCOM's job involves acquisition and sustainment support for aviation and...
developed, and demonstrated, ruggedized narrow-linewidth laser oscillators tunable directly in the visible spectrum. This pioneering work led to experimentation with polymer gain media and in 1994 Duarte reported on the first narrow-linewidth tunable solid state dye laser
Solid state dye lasers
Solid state dye lasers were introduced in 1967 by Soffer and McFarland. In these solid state lasers, the gain medium is a laser dye-doped organic matrix such as poly , rather than a liquid solution of the dye...
oscillators. These dispersive oscillator architectures were then refined to yield single-longitudinal-mode emission limited only by Heisenberg's uncertainty principle
Uncertainty principle
In quantum mechanics, the Heisenberg uncertainty principle states a fundamental limit on the accuracy with which certain pairs of physical properties of a particle, such as position and momentum, can be simultaneously known...
. His work on solid-state organic-inorganic materials led to the assessment of intra-gain-medium interference
phenomena and to the emission of low-divergence homogeneous laser beams from polymer-nanoparticle
Nanoparticle
In nanotechnology, a particle is defined as a small object that behaves as a whole unit in terms of its transport and properties. Particles are further classified according to size : in terms of diameter, coarse particles cover a range between 10,000 and 2,500 nanometers. Fine particles are sized...
gain media. In 2005 Duarte and colleagues were the first to demonstrate coherent emission from an electrically excited organic semiconductor
Organic light-emitting diode
An OLED is a light-emitting diode in which the emissive electroluminescent layer is a film of organic compounds which emit light in response to an electric current. This layer of organic semiconductor material is situated between two electrodes...
.
Tunable lasers for isotope separation
As previously outlined, Duarte and Piper developed narrow-linewidth multiple-prism grating laser oscillators whose designs have been adopted by various research groups working on uraniumUranium
Uranium is a silvery-white metallic chemical element in the actinide series of the periodic table, with atomic number 92. It is assigned the chemical symbol U. A uranium atom has 92 protons and 92 electrons, of which 6 are valence electrons...
atomic vapor laser isotope separation (AVLIS). This work was supported by the Australian Atomic Energy Commission
Australian Atomic Energy Commission
The Australian Atomic Energy Commission 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, the remainder continuing until 1987, when it was replaced by...
. In a review article, Duarte discloses that during the course of this research he did approach the then federal minister for energy, Sir John L. Carrick
John Carrick (Australian politician)
Sir John Leslie Carrick, AC, KCMG is a former Australian politician.-Early life:Carrick studied economics at the University of Sydney . Before he was able to commence his career to any great degree he fought with the Sparrow Force of the Australian Army during World War II. He was landed on...
, to advocate for the introduction of an AVLIS facility in Australia. In 2002, he participated in research that led to the isotope separation of lithium
Lithium
Lithium is a soft, silver-white metal that belongs to the alkali metal group of chemical elements. It is represented by the symbol Li, and it has the atomic number 3. Under standard conditions it is the lightest metal and the least dense solid element. Like all alkali metals, lithium is highly...
using tunable diode lasers.
Interferometry
In the late 1980s, Duarte applied Dirac’s notation to describe quantum mechanically the N-slit laser interferometerN-Slit interferometer
The N-slit interferometer is an extension of the double-slit interferometer also known as Young's double-slit interferometer. One of the first known uses of N-slit arrays in optics was illustrated by Newton...
and to solve problems in industrial imaging and optical metrology. The electro-optical N-slit interferometer uses prismatic beam expansion
Beam expander
Beam expanders are used in laser physics either as intracavity or extracavity elements. They can be telescopic in nature or prismatic. Generally prismatic beam expanders use several prisms and are known as multiple-prism beam expanders....
to illuminate the N-slit array and comprises a photodiode array (or digital detector), at the interference plane, to register the interferograms. This work also led to a generalized N-slit interferometric equation
N-slit interferometric equation
Quantum mechanics was first applied to optics, and interference in particular, by Paul Dirac. Feynman, in his lectures, uses Dirac’s notation to describe thought experiments on double-slit interference of electrons...
that was then applied to describe interference, diffraction
Diffraction
Diffraction refers to various phenomena which occur when a wave encounters an obstacle. Italian scientist Francesco Maria Grimaldi coined the word "diffraction" and was the first to record accurate observations of the phenomenon in 1665...
, refraction
Refraction
Refraction is the change in direction of a wave due to a change in its speed. It is essentially a surface phenomenon . The phenomenon is mainly in governance to the law of conservation of energy. The proper explanation would be that due to change of medium, the phase velocity of the wave is changed...
, and reflection
Reflection (physics)
Reflection is the change in direction of a wavefront at an interface between two differentmedia so that the wavefront returns into the medium from which it originated. Common examples include the reflection of light, sound and water waves...
, in a rational and unified approach.
More recently, Duarte and colleagues have developed very large N-slit laser interferometers to generate and propagate interferometric characters for secure free-space optical communications
Free-space optical communication
Free-space optical communication is an optical communication technology that uses light propagating in free space to transmit data for telecommunications or computer networking."Free space" means air, outer space, vacuum, or something similar...
. These experiments have also provided the first observation of diffraction patterns superimposed over propagating interference signals.
Macquarie University
Duarte studied physics at Macquarie UniversityMacquarie University
Macquarie University is an Australian public teaching and research university located in Sydney, with its main campus situated in Macquarie Park. Founded in 1964 by the New South Wales Government, it was the third university to be established in the metropolitan area of Sydney...
(Sydney, Australia) where he also established and led the successful science reform movement
Macquarie science reform movement
Macquarie science reform movement refers to the successfultransformation of the degree system at Macquarie University in 1979which followed an academic and political campaign initiated in 1977.Macquarie University, founded in 1964, adopted a degree structure...
of the late 1970s. Science reform, at Macquarie, was widely supported by local scientists including physicists Ronald Ernest Aitchison
Ronald Ernest Aitchison
Ronald Ernest Aitchison , was born in Hurstville, NSW, Australia on 29 December 1921. From 1942 to 1945 Ron worked as an engineer with the Amalgamated Wireless Valve Company on the design and production of klystrons and radar magnetrons, which were new devices important to the war effort...
, R. E. B. Makinson, and the famed John Clive Ward
John Clive Ward
John Clive Ward , was a British-Australian physicist. His most famous creation was the Ward-Takahashi identity, originally known as "Ward Identity" . This celebrated result, in quantum electrodynamics, was inspired by a conjecture of Dyson and was disclosed in a one-half page letter typical of...
. His career path includes post-doctoral research in Australia, plus academic and industrial-research appointments in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
.
Recognitions
Duarte was elected Fellow of the Australian Institute of Physics (1987) and FellowOSA Fellow
The OSA Fellow, of the Optical Society of America, is a membership designation.The bylaws of this society only allow 10% of its membership to be designated as an OSA Fellow. The OSA Fellow is peer group nomination.-The nominee:...
of the Optical Society of America (1993) for his contributions to the development of narrow-linewidth
Laser linewidth
←Laser linewidth is the spectral linewidth of a laser beam.Two of the most distinctive characteristics of laser emission are spatial coherence and spectral coherence. While spatial coherence is related to the beam divergence of the laser, spectral coherence is evaluated by measuring the laser...
tunable lasers
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 range....
. He is the first South American to have received such distinctions. Subsequently, he received the prestigious Engineering Excellence Award from the Optical Society of America for the invention of the N-slit laser interferometer
N-Slit interferometer
The N-slit interferometer is an extension of the double-slit interferometer also known as Young's double-slit interferometer. One of the first known uses of N-slit arrays in optics was illustrated by Newton...
. Duarte's contributions are cited in well over a hundred scholarly books, including several classics.
See also
- Multiple-prism grating laser oscillators
- Prism pulse compressorsPrism compressorA prism compressor is an optical device used to shorten the duration of a positively chirped ultrashort laser pulse by giving different wavelength components a different time delay. It typically consists of two prisms and a mirror. Figure 1 shows the construction of such a compressor...
- Solid state dye lasersSolid state dye lasersSolid state dye lasers were introduced in 1967 by Soffer and McFarland. In these solid state lasers, the gain medium is a laser dye-doped organic matrix such as poly , rather than a liquid solution of the dye...
External links
- Duarte's home page
- Prism and Multiple-Prism Pulse Compression: Tutorial
- Tunable Laser Books
- United States Patents by F. J. Duarte, at Patent Genius
- Group photograph including, right to left, Marlan ScullyMarlan ScullyMarlan Orvil Scully is a physicist best known for his work in theoretical quantum optics. He is currently a professor at Texas A&M University and Princeton University. He has authored over 700 scientific articles, as well as standard textbooks such as “Laser Physics” and “Quantum Optics” ...
, Willis LambWillis LambWillis Eugene Lamb, Jr. was an American physicist who won the Nobel Prize in Physics in 1955 together with Polykarp Kusch "for his discoveries concerning the fine structure of the hydrogen spectrum". Lamb and Kusch were able to precisely determine certain electromagnetic properties of the electron...
, John L. HallJohn L. HallJohn Lewis "Jan" Hall is an American physicist, and Nobel laureate in physics. He shared one half of the 2005 Nobel Prize in Physics with Theodor W. Hänsch for his work in precision spectroscopy.-Biography:...
, and F. J. Duarte.