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Biographical Memoirs of Fellows of the Royal Society

Daniel Frank Walls FRSNZ. 13 September 1942 — 12 May 1999

P. L. Knight, Gerard J Milburn

Published Jan 1, 2015• 0 citations
Publisher

Abstract

Dan Walls, a pioneer of quantum optics and especially the study of non-classical light, died in Auckland on 12 May 1999 after a battle with cancer, at the age of 57 years. Dan Walls completed a PhD with Roy Glauber at Harvard in 1969 and joined the University of Waikato in 1972. Together with his colleague Crispin Gardiner, during the next 25 years he established a major research centre for theoretical quantum optics in New Zealand and built active and productive collaborations with groups throughout the world.

DOI
10.1098/rsbm.2014.0019

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Introduction

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The Workshop on Atom Optics was held at the University of Adelaide in September 1995. It was attended by pproximately 40 physicists from Australia and New Zealand. The venue for the workshop was the new Institute for Theoretical Physics at the University of Adelaide which provided excellent facilities for lectures and discussion. Atom optics is a field which has grown rapidly since its beginning approximately five years ago. There are now several groups in Australia and New Zealand pursuing research activities in both theoretical and experimental aspects of atom optics.

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Michael Stephen Feld died in Boston on 10 April 2010, at age 69, after an eight-year struggle with multiple myeloma. He was widely known for his contributions to fundamental laser physics and for pioneering lasers and spectroscopy to biomedical problems.Feld was born 11 November 1940 in Brooklyn, New York. He graduated from Lynbrook High School on Long Island in 1958 and from MIT in 1963 with an SB degree in humanities and sciences and an SM degree in physics. He stayed on at MIT to earn a PhD in physics in 1967 for research on laser spectroscopy under Ali Javan. In 1968 Feld joined the MIT physics department as an assistant professor and went on to a varied and productive career as a member of the physics faculty. Feld’s graduate research laid the foundation for a lifelong interest in quantum optics. He established his presence in that field by demonstrating superradiance—the enhancement by coherence effects of the emission of light from a collection of radiators—in a molecular gas. By pursuing that problem in the face of skeptics who thought that Doppler broadening would make the effect impossible to observe, he demonstrated an independence of thought and scientific determination that would mark his career. His research in quantum optics led Feld into the field of cavity quantum electrodynamics. In 1987 he began a series of experiments on radiative shifts and enhanced and suppressed spontaneous emission of single atoms in an optical resonator. Those culminated in his development of the single-atom laser in 1994.From 1976 until his death, Feld was director of MIT’s Harrison Spectros-copy Laboratory. In that role he fostered collaborations among physicists, chemists, biologists, materials scientists, and physicians by welcoming them to participate in the laboratory. To support cooperative research, he established the MIT Regional Laser Facility, funded by NSF, and the MIT Laser Biomedical Research Center, funded by the National Institutes of Health. One of the research center’s many achievements was the development of the diffraction phase microscope (shown in the photo), which yields nanoscale quantitative measurements of the structure and dynamics of live red blood cells.Feld was notably direct. He questioned with equal intensity, acuteness, and persistence academic administrators, janitors, colleagues, waiters, students, and deliverymen. That quality helped him develop fruitful collaborations with scientists from a wide range of fields. Starting in the 1980s, those collaborations helped him turn his attention increasingly to applying lasers and laser-based techniques to biomedicine and biomedical engineering. Feld was an early leader in the use of light scattering, fluorescence spectroscopy, and Raman spectroscopy to investigate arterial plaque in vivo and to provide early cancer detection in some organs. In recent years his research shifted; rather than use those intensity-based modalities, he used field-based light scattering to develop low-coherence interferometry and to explore how to suppress turbidity and obtain images from inside apparently opaque tissue. Near-IR Raman spectroscopy has made it possible to measure levels of blood glucose through the skin without the prick of a needle. Quantitative phase microscopy has produced three-dimensional maps of the refractive index of live cells free of labels or dyes. It also permits early diagnosis of breast cancer and assessment of whether cells at the margins of a cancerous lesion are themselves cancerous. For his foundational contributions to laser spectroscopy and the biomedical use of spectroscopy, Feld received the 2008 William F. Meggers Award from the Optical Society of America.Throughout his career Feld enthusiastically engaged in undergraduate and graduate teaching at MIT. He supervised more than 50 PhD theses. Reflecting his breadth of interest, they were in chemistry, mechanical engineering, bioengineering, and materials research, as well as in physics, and several were part of the MIT-Harvard Health Sciences and Technology program.The 1963 March on Washington marked the beginning of Feld’s lifelong concern about minority graduate education in physics at MIT. He cochaired the committee that initiated establishment of MIT’s Dr Martin Luther King Jr Visiting Professors Program, and, with characteristic direct action, he personally guided five minority graduate students to their PhD degrees.One of those students was Ronald McNair, who went on to a career as an astronaut. Feld and McNair became close friends, and their teaching was reciprocal: Feld mentored McNair in physics; McNair taught Feld karate. Feld obtained a brown belt and was proud to be outdone by his twin sons, Jonathan and David, who became black belts. As was typical, once Feld became interested in karate, he made a serious study of its physics. He presented widely appreciated talks on the physics of karate with demonstrations that sometimes included his sons; he and McNair coauthored articles on karate. McNair’s death in the space shuttle Challenger accident in 1986 was a deep personal loss for Feld.Michael Feld was a creative, innovative physicist and a man of great charm, always asking for more effort, more time, and more insight from his collaborators and students. Many of them are today advancing laser physics, quantum optics, biomedicine, and biomedical engineering along paths that he opened. Through their work Feld’s already large impact on the scientific community continues to grow.Michael Stephen FeldDONNA COVENEY, MIT MEWS SERVICEPPT|High resolution© 2010 American Institute of Physics.

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In the early hours of 9 February 2001, the physics community lost one of its most distinguished members, Leonard Mandel, after a long illness. Mandel was the Lee DuBridge Professor Emeritus of Physics and Optics at the University of Rochester, having become emeritus only a few months before he died, at the age of 73, at his home in Pittsford, New York.Born on 9 May 1927 in Berlin, Germany, where his father had emigrated from Eastern Europe, Mandel received a BSc in mathematics and physics in 1947 and a PhD in nuclear physics in 1951 from Birkbeck College, University of London, in the UK. He became a technical officer at Imperial Chemical Industries Ltd in Welwyn, UK, in 1951. In 1955, he became a lecturer and, later, senior lecturer at Imperial College, University of London. He remained at Imperial College until 1964, when he joined the University of Rochester as a professor of physics. Mandel is widely credited as being one of the founding fathers of the field of quantum optics. Although he made seminal contributions across most of quantum optics, the central theme of his research was the exploration of the nature of light through insightful theoretical analyses and a set of pioneering experiments that have become landmarks in the field. Not since the beginning of quantum mechanics has an individual so intimately investigated and so dramatically advanced our understanding of the quantum aspects of light.Mandel’s early interest in quantum optics was stimulated by the Hanbury Brown–Twiss experiments, in which correlations in the fluctuations of photocurrents from two photodetectors illuminated by light from a distant source reveal information about the spatial coherence properties of the light. Mandel’s entrance into the debate about the appropriate theoretical description of this experiment was a basic paper published in 1958 in the Proceedings of the Physical Society (London) in which the so-called Mandel formula for photoelectric counting made its first appearance.In 1968, Mandel’s research group performed the now famous experiment involving interference at the single photon level: Two beams derived from independent lasers were attenuated to a level such that the average interval between photon emissions was very long compared to the transit time through the apparatus. Interference fringes were nonetheless recorded. As in the Hanbury Brown–Twiss experiment, the detection scheme explored interference of the fourth order in the amplitudes of the fields, as opposed to the more familiar second-order interference (as in a Michelson interferometer, for example), but now with an ingenious extension. Over the next three decades, Mandel continued to refine fourth-order interferometry into a powerful tool for investigating the quantum nature of light. It is now a standard technique used worldwide.Perhaps spurred by the debate about the quantum statistical properties of lasers and other light sources, Mandel and his students were among the first to carry out basic experiments from 1967 to 1968 to elucidate the coherence properties of the laser in the transition from incoherent to coherent emission around threshold. In the ensuing decades, those early studies grew into diverse investigations of more complex laser behavior, including mode correlation and competition in ring lasers, and optical bistability and first-order phase transitions in dye lasers. Mandel played a leading role in the quest to investigate states of the electromagnetic field with manifestly quantum or nonclassical characteristics. In 1977, his group made a historic advance in this endeavor with the first observation of photon anti-bunching in the case of the fluorescent light from a single atom. Subsequently, Mandel and one of his students made the first measurements of another nonclassical effect, namely, sub-Poissonian photon statistics. In the early 1980s, Mandel initiated what would become a landmark set of experiments involving pairs of photons produced by the fission of a pump photon in the process of parametric down conversion. Following earlier work by others on the correlation between photon pairs in atomic cascades, Mandel and his students first demonstrated a key nonclassical aspect of the down conversion process and were able to achieve a localized one-photon state.Pursuing the theme of fourth-order interference with pairs of photons in the late 1980s, Mandel and his students demonstrated quantum spatial beating, violations of local realism, and phase memory due to quantum entanglement with the vacuum. His group showed that P. A. M. Dirac’s well-known statement about single-photon interference must be modified to assert that, in fourth-order interference, a pair of photons interferes only with the pair itself. He and his students also introduced what became known as the Hong-Ou-Mandel interferometer. Beyond what had by then become “the standard model” of manifestly quantum effects, Mandel’s genius for probing the quantum realm led to advances throughout the 1990s that challenged and ultimately redefined our understanding of the quantum character of light and, more generally, of quantum measurement. For example, in 1991, Mandel and his students reported a remarkable experiment involving interference from the superposition of fields from two different but coherent parametric processes. They showed that the mere possibility of making a measurement destroyed an interference pattern, even if this possibility went unrealized. In 1995, Mandel’s group, in an experiment with photon pairs, demonstrated a central tenet of quantum mechanics: that there is no physical reality for elemental quantum processes in the absence of a measurement. Mandel supervised the thesis research of 39 students, many of whom have subsequently become leading figures in science and technology. He earned the lifelong respect of his students for his detailed and conscientious stewardship of their scientific development. He made frequent rounds of his laboratories to interact with each of his students and to provide help ranging from optical alignment and electronic design to theoretical calculations. Not wanting to interrupt a student at work, he would sometimes quietly approach in his soft-soled shoes to view the activity at hand, leading to more than a few startled heart skips. In response to a student’s query, “Can you see a signal yet?” as some component of an apparatus was being aligned, would come his distinctively British reply, “Not a sausage!” Once, when the need arose to regulate the water cooling for an oil diffusion pump, he solved the problem the next morning with a flow switch commandeered from a washing machine at home.In addition to his work at the frontiers of physics, Mandel was an excellent teacher. He had a special interest in neophyte science students and developed the first course at the University of Rochester for non-science majors, which he taught regularly for 20 years. From 1966 to 1995, he was one of the main organizers of a well-known series of international conferences called the Rochester Conferences on Coherence and Quantum Optics. Mandel was the coauthor of Optical Coherence and Quantum Optics (Cambridge U. Press, 1995) and the coeditor of several conference proceedings. In 1980, a paper on coherence properties of optical fields, which he coauthored in 1965, was designated a Citation Classic by the Institute of Scientific Publications. In 1988, that paper was listed as one of the 100 most-cited articles published in the Review of Modern Physics since 1955. Mandel received many top awards, including the Frederic Ives Medal (1993) and the Max Born Medal (1982) from the Optical Society of America. He received the Marconi Medal (1987) from the Italian Research Council and the Thomas Young Award (1989) from the British Institute of Physics. In May 2001, Mandel was elected posthumously to membership in the National Academy of Sciences.Mandel was a scientist with a warm personality, humility, compassion, and a delightful sense of humor. He enjoyed a happy family life with his wife Jeanne, a ballet teacher with whom he shared the love for ballet, and with their two children. He adored his four grandchildren and took lively interest in all their activities. Those of us who were fortunate to have been associated with Mandel as students, colleagues, or friends will remember him with deep affection and utmost respect. He will be greatly missed. Leonard Mandel PPT|High resolution© 2001 American Institute of Physics.

Physics Today•Aug 1, 2001•0 citations

An interview with Nobel laureate Roy Glauber, Physics 2005

Roy J. Glauber

The field of quantum optics rests on the work of Roy Glauber, who helped elucidate the nature of light as both particles and waves. According to Glauber, quantum optics allowed "all sorts of experiments...that never could have been done before." He suggests that it was not his "small revelation" that the Nobel Committee awarded, but rather the decades of research that followed his own. Nonetheless, Glauber received one-half of the 2005 Nobel Prize in Physics "for his contribution to the quantum theory of optical coherence" while the other half was shared by John Hall and Theodor Hänsch for their work on laser-based precision spectroscopy. Glauber admits that the behavior of light seems strange and unintuitive--yet the phenomena that Einstein called "spooky action at a distance" may have many practical applications. In this candid interview, Glauber shares his thoughts about working at Los Alamos National Laboratory--his shock to learn that he was helping to build The Bomb, and his dismay about how it was used. At Los Alamos, Glauber met two of his major influences: Julian Schwinger, who was Glauber's thesis advisor at Harvard, and Los Alamos scientific director Robert Oppenheimer, who facilitated his early post-doctoral research. Glauber also tells a poignant account of how his marriage fell victim to the social upheaval of the 1960's, and how he was left to raise two children alone. Despite the difficulties of reconciling academia with family, Glauber is amused to find himself revered by women as "someone who has raised children and nonetheless had a successful academic career."

Journal of Visualized Experiments•Jun 26, 2009•0 citations
Dan Walls, a pioneer of quantum optics and especially the study of non-classical light, died in Auckland on 12 May 1999 after a battle with cancer, at the age of 57 years. Dan Walls completed a PhD with Roy Glauber at Harvard in 1969 and joined the University of Waikato in 1972. Together with his colleague Crispin Gardiner, during the next 25 years he established a major research centre for theoretical quantum optics in New Zealand and built active and productive collaborations with groups throughout the world.
The Workshop on Atom Optics was held at the University of Adelaide in September 1995. It was attended by pproximately 40 physicists from Australia and New Zealand. The venue for the workshop was the new Institute for Theoretical Physics at the University of Adelaide which provided excellent facilities for lectures and discussion. Atom optics is a field which has grown rapidly since its beginning approximately five years ago. There are now several groups in Australia and New Zealand pursuing research activities in both theoretical and experimental aspects of atom optics.
Michael Stephen Feld died in Boston on 10 April 2010, at age 69, after an eight-year struggle with multiple myeloma. He was widely known for his contributions to fundamental laser physics and for pioneering lasers and spectroscopy to biomedical problems.Feld was born 11 November 1940 in Brooklyn, New York. He graduated from Lynbrook High School on Long Island in 1958 and from MIT in 1963 with an SB degree in humanities and sciences and an SM degree in physics. He stayed on at MIT to earn a PhD in physics in 1967 for research on laser spectroscopy under Ali Javan. In 1968 Feld joined the MIT physics department as an assistant professor and went on to a varied and productive career as a member of the physics faculty. Feld’s graduate research laid the foundation for a lifelong interest in quantum optics. He established his presence in that field by demonstrating superradiance—the enhancement by coherence effects of the emission of light from a collection of radiators—in a molecular gas. By pursuing that problem in the face of skeptics who thought that Doppler broadening would make the effect impossible to observe, he demonstrated an independence of thought and scientific determination that would mark his career. His research in quantum optics led Feld into the field of cavity quantum electrodynamics. In 1987 he began a series of experiments on radiative shifts and enhanced and suppressed spontaneous emission of single atoms in an optical resonator. Those culminated in his development of the single-atom laser in 1994.From 1976 until his death, Feld was director of MIT’s Harrison Spectros-copy Laboratory. In that role he fostered collaborations among physicists, chemists, biologists, materials scientists, and physicians by welcoming them to participate in the laboratory. To support cooperative research, he established the MIT Regional Laser Facility, funded by NSF, and the MIT Laser Biomedical Research Center, funded by the National Institutes of Health. One of the research center’s many achievements was the development of the diffraction phase microscope (shown in the photo), which yields nanoscale quantitative measurements of the structure and dynamics of live red blood cells.Feld was notably direct. He questioned with equal intensity, acuteness, and persistence academic administrators, janitors, colleagues, waiters, students, and deliverymen. That quality helped him develop fruitful collaborations with scientists from a wide range of fields. Starting in the 1980s, those collaborations helped him turn his attention increasingly to applying lasers and laser-based techniques to biomedicine and biomedical engineering. Feld was an early leader in the use of light scattering, fluorescence spectroscopy, and Raman spectroscopy to investigate arterial plaque in vivo and to provide early cancer detection in some organs. In recent years his research shifted; rather than use those intensity-based modalities, he used field-based light scattering to develop low-coherence interferometry and to explore how to suppress turbidity and obtain images from inside apparently opaque tissue. Near-IR Raman spectroscopy has made it possible to measure levels of blood glucose through the skin without the prick of a needle. Quantitative phase microscopy has produced three-dimensional maps of the refractive index of live cells free of labels or dyes. It also permits early diagnosis of breast cancer and assessment of whether cells at the margins of a cancerous lesion are themselves cancerous. For his foundational contributions to laser spectroscopy and the biomedical use of spectroscopy, Feld received the 2008 William F. Meggers Award from the Optical Society of America.Throughout his career Feld enthusiastically engaged in undergraduate and graduate teaching at MIT. He supervised more than 50 PhD theses. Reflecting his breadth of interest, they were in chemistry, mechanical engineering, bioengineering, and materials research, as well as in physics, and several were part of the MIT-Harvard Health Sciences and Technology program.The 1963 March on Washington marked the beginning of Feld’s lifelong concern about minority graduate education in physics at MIT. He cochaired the committee that initiated establishment of MIT’s Dr Martin Luther King Jr Visiting Professors Program, and, with characteristic direct action, he personally guided five minority graduate students to their PhD degrees.One of those students was Ronald McNair, who went on to a career as an astronaut. Feld and McNair became close friends, and their teaching was reciprocal: Feld mentored McNair in physics; McNair taught Feld karate. Feld obtained a brown belt and was proud to be outdone by his twin sons, Jonathan and David, who became black belts. As was typical, once Feld became interested in karate, he made a serious study of its physics. He presented widely appreciated talks on the physics of karate with demonstrations that sometimes included his sons; he and McNair coauthored articles on karate. McNair’s death in the space shuttle Challenger accident in 1986 was a deep personal loss for Feld.Michael Feld was a creative, innovative physicist and a man of great charm, always asking for more effort, more time, and more insight from his collaborators and students. Many of them are today advancing laser physics, quantum optics, biomedicine, and biomedical engineering along paths that he opened. Through their work Feld’s already large impact on the scientific community continues to grow.Michael Stephen FeldDONNA COVENEY, MIT MEWS SERVICEPPT|High resolution© 2010 American Institute of Physics.
Quantum optics was born in the first years of the 20th century. The first papers leading to further ideas of quanta of light were presented by Max Planck and Albert Einstein. Their pioneering papers laid the foundations for the theory of quantum optics. However, one should remember that for the birth of the formal theory of quantisation of light, the development of quantum mechanics was necessary. Interestingly, the word ’photon’ appeared for the first time in a paper by a Gilbert Lewis, a chemist, in 1926 and was later used by P.A.M. Dirac, a physicist, the next year. The modern sense of the term quantum optics was established in 1956 when Hanbury Brown and Twiss built the intensity interferometr and performed their famous experiment in which correlations between two light beams were measured. Although the results of their experiment could be explained on the basis of the classical theory of light, with some quantumcomponent to the process of photodetection, their result is commonly accepted as the beginning of the modern quantum optics era. The next milestone in the development of quantum optics was the invention of laser in 1960. The physical properties of the light generated by lasers were considerably different from those characterising the light generated by classical thermal sources. This fact was a great impulse leading to further development of quantum optics’ ideas. The first of them were presented in the fundamental papers written by Glauber, describing new states of light quantum coherent states.
In the early hours of 9 February 2001, the physics community lost one of its most distinguished members, Leonard Mandel, after a long illness. Mandel was the Lee DuBridge Professor Emeritus of Physics and Optics at the University of Rochester, having become emeritus only a few months before he died, at the age of 73, at his home in Pittsford, New York.Born on 9 May 1927 in Berlin, Germany, where his father had emigrated from Eastern Europe, Mandel received a BSc in mathematics and physics in 1947 and a PhD in nuclear physics in 1951 from Birkbeck College, University of London, in the UK. He became a technical officer at Imperial Chemical Industries Ltd in Welwyn, UK, in 1951. In 1955, he became a lecturer and, later, senior lecturer at Imperial College, University of London. He remained at Imperial College until 1964, when he joined the University of Rochester as a professor of physics. Mandel is widely credited as being one of the founding fathers of the field of quantum optics. Although he made seminal contributions across most of quantum optics, the central theme of his research was the exploration of the nature of light through insightful theoretical analyses and a set of pioneering experiments that have become landmarks in the field. Not since the beginning of quantum mechanics has an individual so intimately investigated and so dramatically advanced our understanding of the quantum aspects of light.Mandel’s early interest in quantum optics was stimulated by the Hanbury Brown–Twiss experiments, in which correlations in the fluctuations of photocurrents from two photodetectors illuminated by light from a distant source reveal information about the spatial coherence properties of the light. Mandel’s entrance into the debate about the appropriate theoretical description of this experiment was a basic paper published in 1958 in the Proceedings of the Physical Society (London) in which the so-called Mandel formula for photoelectric counting made its first appearance.In 1968, Mandel’s research group performed the now famous experiment involving interference at the single photon level: Two beams derived from independent lasers were attenuated to a level such that the average interval between photon emissions was very long compared to the transit time through the apparatus. Interference fringes were nonetheless recorded. As in the Hanbury Brown–Twiss experiment, the detection scheme explored interference of the fourth order in the amplitudes of the fields, as opposed to the more familiar second-order interference (as in a Michelson interferometer, for example), but now with an ingenious extension. Over the next three decades, Mandel continued to refine fourth-order interferometry into a powerful tool for investigating the quantum nature of light. It is now a standard technique used worldwide.Perhaps spurred by the debate about the quantum statistical properties of lasers and other light sources, Mandel and his students were among the first to carry out basic experiments from 1967 to 1968 to elucidate the coherence properties of the laser in the transition from incoherent to coherent emission around threshold. In the ensuing decades, those early studies grew into diverse investigations of more complex laser behavior, including mode correlation and competition in ring lasers, and optical bistability and first-order phase transitions in dye lasers. Mandel played a leading role in the quest to investigate states of the electromagnetic field with manifestly quantum or nonclassical characteristics. In 1977, his group made a historic advance in this endeavor with the first observation of photon anti-bunching in the case of the fluorescent light from a single atom. Subsequently, Mandel and one of his students made the first measurements of another nonclassical effect, namely, sub-Poissonian photon statistics. In the early 1980s, Mandel initiated what would become a landmark set of experiments involving pairs of photons produced by the fission of a pump photon in the process of parametric down conversion. Following earlier work by others on the correlation between photon pairs in atomic cascades, Mandel and his students first demonstrated a key nonclassical aspect of the down conversion process and were able to achieve a localized one-photon state.Pursuing the theme of fourth-order interference with pairs of photons in the late 1980s, Mandel and his students demonstrated quantum spatial beating, violations of local realism, and phase memory due to quantum entanglement with the vacuum. His group showed that P. A. M. Dirac’s well-known statement about single-photon interference must be modified to assert that, in fourth-order interference, a pair of photons interferes only with the pair itself. He and his students also introduced what became known as the Hong-Ou-Mandel interferometer. Beyond what had by then become “the standard model” of manifestly quantum effects, Mandel’s genius for probing the quantum realm led to advances throughout the 1990s that challenged and ultimately redefined our understanding of the quantum character of light and, more generally, of quantum measurement. For example, in 1991, Mandel and his students reported a remarkable experiment involving interference from the superposition of fields from two different but coherent parametric processes. They showed that the mere possibility of making a measurement destroyed an interference pattern, even if this possibility went unrealized. In 1995, Mandel’s group, in an experiment with photon pairs, demonstrated a central tenet of quantum mechanics: that there is no physical reality for elemental quantum processes in the absence of a measurement. Mandel supervised the thesis research of 39 students, many of whom have subsequently become leading figures in science and technology. He earned the lifelong respect of his students for his detailed and conscientious stewardship of their scientific development. He made frequent rounds of his laboratories to interact with each of his students and to provide help ranging from optical alignment and electronic design to theoretical calculations. Not wanting to interrupt a student at work, he would sometimes quietly approach in his soft-soled shoes to view the activity at hand, leading to more than a few startled heart skips. In response to a student’s query, “Can you see a signal yet?” as some component of an apparatus was being aligned, would come his distinctively British reply, “Not a sausage!” Once, when the need arose to regulate the water cooling for an oil diffusion pump, he solved the problem the next morning with a flow switch commandeered from a washing machine at home.In addition to his work at the frontiers of physics, Mandel was an excellent teacher. He had a special interest in neophyte science students and developed the first course at the University of Rochester for non-science majors, which he taught regularly for 20 years. From 1966 to 1995, he was one of the main organizers of a well-known series of international conferences called the Rochester Conferences on Coherence and Quantum Optics. Mandel was the coauthor of Optical Coherence and Quantum Optics (Cambridge U. Press, 1995) and the coeditor of several conference proceedings. In 1980, a paper on coherence properties of optical fields, which he coauthored in 1965, was designated a Citation Classic by the Institute of Scientific Publications. In 1988, that paper was listed as one of the 100 most-cited articles published in the Review of Modern Physics since 1955. Mandel received many top awards, including the Frederic Ives Medal (1993) and the Max Born Medal (1982) from the Optical Society of America. He received the Marconi Medal (1987) from the Italian Research Council and the Thomas Young Award (1989) from the British Institute of Physics. In May 2001, Mandel was elected posthumously to membership in the National Academy of Sciences.Mandel was a scientist with a warm personality, humility, compassion, and a delightful sense of humor. He enjoyed a happy family life with his wife Jeanne, a ballet teacher with whom he shared the love for ballet, and with their two children. He adored his four grandchildren and took lively interest in all their activities. Those of us who were fortunate to have been associated with Mandel as students, colleagues, or friends will remember him with deep affection and utmost respect. He will be greatly missed. Leonard Mandel PPT|High resolution© 2001 American Institute of Physics.
The field of quantum optics rests on the work of Roy Glauber, who helped elucidate the nature of light as both particles and waves. According to Glauber, quantum optics allowed "all sorts of experiments...that never could have been done before." He suggests that it was not his "small revelation" that the Nobel Committee awarded, but rather the decades of research that followed his own. Nonetheless, Glauber received one-half of the 2005 Nobel Prize in Physics "for his contribution to the quantum theory of optical coherence" while the other half was shared by John Hall and Theodor Hänsch for their work on laser-based precision spectroscopy. Glauber admits that the behavior of light seems strange and unintuitive--yet the phenomena that Einstein called "spooky action at a distance" may have many practical applications. In this candid interview, Glauber shares his thoughts about working at Los Alamos National Laboratory--his shock to learn that he was helping to build The Bomb, and his dismay about how it was used. At Los Alamos, Glauber met two of his major influences: Julian Schwinger, who was Glauber's thesis advisor at Harvard, and Los Alamos scientific director Robert Oppenheimer, who facilitated his early post-doctoral research. Glauber also tells a poignant account of how his marriage fell victim to the social upheaval of the 1960's, and how he was left to raise two children alone. Despite the difficulties of reconciling academia with family, Glauber is amused to find himself revered by women as "someone who has raised children and nonetheless had a successful academic career."