The Nobel Prize in Physics 1981

• Summary
• Press Release

Nobel Prize Award Ceremony

• Award Ceremony Speech

Nicolaas Bloembergen

• Biographical
• Nobel Lecture

• Banquet Speech
• Interview
• Other Resources

Arthur L. Schawlow

• Biographical
• Nobel Lecture

• Other Resources

Kai M. Siegbahn

• Biographical
• Nobel Lecture

Nicolaas Bloembergen

Born: 11 March 1920, Dordrecht, the Netherlands

Affiliation at the time of the award: Harvard University, Cambridge, MA, USA

Prize motivation: "for their contribution to the development of laser spectroscopy"

Field: Optical physics, quantum electrodynamics

Autobiography

My parents, Auke Bloembergen and Sophia Maria Quint, had four sons and two daughters. I am the second child, born on March 11, 1920, in Dordrecht, the Netherlands. My father, a chemical engineer, was an executive in a chemical fertilizer company. My mother, who had an advanced degree to teach French, devoted all her energies to rearing a large family.

Before I entered grade school, the family moved to Bilthoven, a residential suburb of Utrecht. We were brought up in the protestant work ethic, characteristic of the Dutch provinces. Intellectual pursuits were definitely encouraged. The way of life, however, was much more frugal than the family income would have dictated.

At the age of twelve I entered the municipal gymnasium in Utrecht, founded as a Latin school in 1474. Nearly all teachers held Ph.D. degrees. The rigid curriculum emphasized the humanities: Latin, Greek, French, German, English, Dutch, history and mathematics. My preference for science became evident only in the last years of secondary school, where the basics of physics and chemistry were well taught. The choice of physics was probably based on the fact that I found it the most difficult and challenging subject, and I still do to this day. My maternal grandfather was a high school principal with a Ph.D. in mathematical physics. So there may be some hereditary factor as well. I am ever more intrigued by the correspondence between mathematics and physical facts. The adaptability of mathematics to the description of physical phenomena is uncanny.

My parents made a rule that my siblings should tear me away from books at certain hours. The periods of relaxation were devoted to sports: canoing, sailing, swimming, rowing and skating on the Dutch waterways, as well as the competitive team sport of field hockey. I now attempt to keep the body fit by playing tennis, by hiking and by skiing.

Professor L.S. Ornstein taught the undergraduate physics course when I entered the University of Utrecht in 1938. He permitted me and my partner in the undergraduate lab, J.C. Kluyver (now professor of physics in Amsterdam) to skip some lab routines and instead assist a graduate student, G.A. W. Rutgers, in a Ph.D. research project. We were thrilled to see our first publication, "On the straggling of Po-a-particles in solid matter", in print (Physica 7, 669, 1940).

After the German occupation of Holland in May 1940, the Hitler regime removed Ornstein from the university in 1941. I made the best possible use of the continental academic system, which relied heavily on independent studies. I took a beautiful course on statistical mechanics by L. Rosenfeld, did experimental work on noise in photoelectric detectors, and prepared the notes for a seminar on Brownian motion given by J.M.W. Milatz. Just before the Nazis closed the university completely in 1943, I managed to obtain the degree of Phil. Drs., equivalent to a M.Sc. degree. The remaining two dark years of the war I spent hiding indoors from the Nazis, eating tulip bulbs to fill the stomach and reading Kramers' book "Quantum Theorie des Elektrons und der Strahlung" by the light of a storm lamp. The lamp needed cleaning every twenty minutes, because the only fuel available was some left-over number two heating oil. My parents did an amazing job of securing the safety and survival of the family.

I had always harbored plans to do some research for a Ph.D. thesis outside the Netherlands, to broaden my perspective. After the devastation of Europe, the only suitable place in 1945 appeared to be the United States. Three applications netted an acceptance in the graduate school at Harvard University. My father financed the trip and the Dutch government obliged by issuing a valuta permit for the purchase of US$ 1,850. As my good fortune would have it, my arrival at Harvard occurred six weeks after Purcell, Torrey and Pound had detected nuclear magnetic resonance (NMR) in condensed matter. Since they were busy writing volumes for the M.I.T. Radiation Laboratory series on microwave techniques, I was accepted as a graduate assistant to develop the early NMR apparatus. My thorough Dutch educational background enabled me to quickly profit from lectures by J. Schwinger, J.H. Van Vleck, E.C. Kemble and others. The hitherto unexplored field of nuclear magnetic resonance in solids, liquids and gases yielded a rich harvest. The results are laid down in one of the most-cited physics papers, commonly referred to as BPP (N. Bloembergen, E.M. Purcell and R.V. Pound, Phys. Rev. 73, 679, 1948). Essentially the same material appears in my Ph.D. thesis, "Nuclear Magnetic Relaxation", Leiden, 1948, republished by W.A. Benjamin, Inc., New York, in 1961. My thesis was submitted in Leiden because I had passed all required examinations in the Netherlands and because C.J. Gorter, who was a visiting professor at Havard during the summer of 1947, invited me to take a postdoctoral position at the Kamerlingh Onnes Laboratorium. My work in Leiden in 1947 and 1948 resulted in establishing the nuclear spin relaxation mechanism by conduction electrons in metals and by paramagnetic impurities in ionic crystals, the phenomenon of spin diffusion, and the large shifts induced by internal magnetic fields in paramagnetic crystals.

During a vacation trip of the Physics Club "Christiaan Huyghens" I met Deli (Huberta Deliana Brink) in the summer of 1948. She had spent the war years in a Japanese concentration camp in Indonesia, where she was born. She was about to start her pre-med studies. When I returned to Harvard in 1949 to join the Society of Fellows, she managed to get on a student hospitality exchange program and traveled after me to the United States on an immigrant ship. I proposed to her the day she arrived and we got married in Amsterdam in 1950. Ever since, she has been a source of light in my life. Her enduring encouragement has contributed immensely to the successes in my further career. After the difficult years as an immigrant wife, raising three children on the modest income of a struggling, albeit tenured, young faculty member, she has found the time and energy to develop her considerable talents as a pianist and artist. We became U.S. citizens in 1958.

Our children are now independent. The older daughter, Antonia, holds M.A. degrees in political science and demography, and works in the Boston area. Our son, Brink, has an M.B.A. degree and is an industrial planner in Oregon. Our younger daughter, Juliana, envisages a career in the financial world. She has interrupted her banking job to obtain an M.B.A. in Philadelphia.

In this family setting my career in teaching and research at Harvard unfolded: Junior Fellow, Society of Fellows 1949 - 1951; Associate Professor 1951- 1957; Gordon McKay Professor of Applied Physics 1957 - 1980; Rumford Professor of Physics 1974 - 1980; Gerhard Gade University Professor 1980 present. While a Junior Fellow, I broadened my experimental background to include microwave spectroscopy and some nuclear physics at the Harvard cyclotron. I preferred the smaller scale experiments of spectroscopy, where an individual, or a few researchers at most, can master all aspects of the problem. When I returned to NMR in 1951, there were still many nuggets to be unearthed. My group studied nuclear quadrupole interactions in alloys and imperfect ionic crystals, discovered the anisotropy of the Knight shift in noncubic metals, the scalar and tensor indirect nuclear spin-spin coupling in metals and insulators, the existence of different temperatures of the Zeeman, exchange and dipolar energies in ferromagnetic relaxation, and a variety of cross relaxation phenomena. All this activity culminated in the proposal for a three-level solid state maser in 1956.

Although I was well aware of the applicability of the multilevel pumping scheme to other frequency ranges, I held the opinion - even after Schawlow and Townes published their proposal for an optical maser in 1958 - that it would be impossible for a small academic laboratory, without previous expertise in optics, to compete successfully in the realization of lasers. This may have been a self-fulfilling prophesy, but it is a matter of record that nearly all types of lasers were first reduced to practice in industrial laboratories, predominantly in the U.S.A.

I recognized in 1961 that my laboratory could exploit some of the new research opportunities made accessible by laser instrumentation. Our group started a program in a field that became known as "Nonlinear Optics". The early results are incorporated in a monograph of this title, published by W. A. Benjamin, New York, in 1965, and the program is still flourishing today. The principal support for all this work, over a period of more than thirty years, has been provided by the Joint Services Electronics Program of the U. S. Department of Defense, with a minimum amount of administrative red tape and with complete freedom to choose research topics and to publish.

My academic career at Harvard has resulted in stimulating interactions with many distinguished colleagues, and also with many talented graduate students. My coworkers have included about sixty Ph.D. candidates and a similar number of postdoctoral research fellows. The contact with the younger generations keeps the mind from aging too rapidly. The opportunities to participate in international summer schools and conferences have also enhanced my professional and social life. My contacts outside the academic towers, as a consultant to various industrial and governmental organizations, have given me an appreciation for the problems of socio-economic and political origin in the "real" world, in addition to those presented by the stubborn realities of matter and instruments in the laboratory.

Sabbatical leaves from Harvard have made it possible for us to travel farther and to live for longer periods of time in different geographical and cultural environments. Fortunately, my wife shares this taste for travel adventure. In 1957 I was a Guggenheim fellow and visiting lecturer at the École Normale Supérieure in Paris, in 1964 - 1965 visiting professor at the University of California in Berkeley, in 1973 Lorentz guest professor in Leiden and visiting scientist at the Philips Research Laboratories in the Netherlands. The fall of 1979 I spent as Raman Visiting Professor in Bangalore, India, and the first semester of 1980 as Von Humboldt Senior Scientist in the Institut für Quantum Optik, in Garching near Munich, as well as visiting professor at the College de France in Paris. I highly value my international professional and social contacts, including two exchange visits to the Soviet Union and one visit to the People's Republic of China, each of one-month duration. My wife and I look forward to continuing our diverse activities and to enjoying our home in Five Fields, Lexington, Massachusetts, where we have lived for 26 years.

From Nobel Lectures, Physics 1981-1990, Editor-in-Charge Tore Frängsmyr, Editor Gösta Ekspång, World Scientific Publishing Co., Singapore, 1993

This autobiography/biography was written at the time of the award and first published in the book series Les Prix Nobel. It was later edited and republished in Nobel Lectures. To cite this document, always state the source as shown above.

Addendum, 1991

In June 1990 I retired from the faculty of Harvard University and became Gerhard Gade University Professor Emeritus. During the past decade I was also a visiting professor or lecturer for extended periods at the California Institute of Technology, at Fermi Scuola Nationale Superiore in Pisa, Italy, and at the University of Munich, Germany.

In 1991 I serve as President of the American Physical Society. I became an honorary professor of Fudan University, Shanghai, People's Republic of China, and received honorary doctorates from Laval University, Quebec, the University of Connecticut and the University of Hartford. In 1983 I received the Medal of Honor from the Institute of Electrical and Electronic Engineers.

My research in nonlinear optics continued with special emphasis on interactions of picosecond and femtosecond laser pulses with condensed matter and of collision-induced optical coherences. My personal life and professional activities during the past decade have been a natural continuation of what I described in my autobiographical notes in 1981.