Nicolaas Bloembergen, a Dutch-born American scientist who ate tulip bulbs to survive during World War II and went on to win the Nobel Prize in physics, died Sept. 5 at an assisted living facility in Tucson, Arizona. He was 97.

His son, Brink Bloembergen, who confirmed the death, said the cause was cardiorespiratory failure.

Over a much-honored career that included 40 years on the faculty of Harvard University, Dr. Bloembergen became a pioneer and major contributor in three significant areas of physics, all of which have significant applications in daily life.

He was one of the pioneers in the development of nuclear magnetic resonance (NMR) techniques, which have become invaluable to modern medicine for creating images of the tissues of the body.

One scientific paper that Bloembergen wrote with two other scientists was, for years, one of the most-quoted articles in physics.

Bloembergen was also recognized for making important advances in the development of the maser, a device similar to the laser but that amplifies microwaves rather than light waves.

He was one of three physicists awarded the Nobel Prize in 1981, along with Kai Siegbahn of Sweden and Arthur Schawlow of the United States. The Swedish Academy cited Bloembergen for his work in nonlinear optics. This field has important applications in modern optical communications.

Bloembergen, who once described physics as the science that explains “the how and why of things,” was part of a generation of scientists trained in Europe before World War II who later came to the United States. Their contributions helped put the United States at the forefront of scientific discovery.

Nicolaas Bloembergen was born March 11, 1920, in Dordrecht, the Netherlands. His father was a chemical engineer and executive. His maternal grandfather was a high school principal with a doctorate in mathematical physics.

Bloembergen began to concentrate on physics not because he found it easy but because he considered it “the most and difficult and challenging subject.”

He enrolled at the University of Utrecht in 1938 and obtained the equivalent of a bachelor’s degree (in 1941) and master’s degree (in 1943) before the Nazis shut down the institution. He later went into hiding and endured such privation that he recalled the winter of 1944 as the “hunger winter.”

Concealed from the Nazis, with food almost impossible to find, he ate tulip bulbs. They required long preparation and provided little nourishment, he recalled. But they staved off the worst hunger pangs by filling his stomach.

After the defeat of the Nazis in 1945, Bloembergen was accepted into graduate school at Harvard, where he worked on NMR under 1952 Nobel laureate Edward Purcell.

Bloembergen complete his PhD in physics at the University of Leiden in his home country in 1948. The next year, he returned to Harvard, where he remained on the faculty until retiring in 1990.

He was said to have never missed a class in his four decades at Harvard. He became a naturalized U.S. citizen in 1958.

In later years, he joined the faculty of the University of Arizona.

Survivors include his wife of 67 years, the former Huberta Deliana Brink of Tucson; and three children.

The title of Bloembergen’s PhD thesis was “Nuclear Magnetic Relaxation.” In this context, relaxation refers to a change in the energy state of a magnetic system composed of the spins of atomic nuclei. The spins of electrically charged particles create circulating electric currents, permitting the particles to be treated as atomic magnets.

Following his NMR work, Bloembergen devoted his attention to the amplification of microwave energy and the device for producing this effect, the maser. The word is the acronym for microwave amplification by stimulated emission of radiation.

The device operated on the principle behind the operation of the better-known and more widely used laser, in which the L stands for light.

With the ability to create extremely intense light beams, it was possible to forge into the unknown areas of nonlinear optics and nonlinear spectroscopy. One of Bloembergen’s major contributions was enabling these nonlinear effects to be understood.

Despite the seriousness with which he approached his work, Bloembergen was not without wit and humor. After his retirement at Harvard, he was made professor emeritus. He described his change in status this way: “A professor can do as he pleases, but a professor emeritus can do as he damn well pleases.”