BLOMBERG Nicholas (Nicolaas Bloembergen)( Netherlands-American physicist, Nobel Prize in Physics, 1981)
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Biography BLOMBERG Nicholas (Nicolaas Bloembergen)
genus. March 11, 1920
Netherlands-American physicist Nicolaas Bloembergen was born in Dordrecht (Netherlands) and was the second of six children from Oka Bloembergen and Sophia Mary (nee Quint) Nicolaas Bloembergen. His father was a chemical engineer with a degree and worked as employees in the company for the production of fertilizers. His mother, the daughter of the headmaster, who had a doctorate in mathematical physics, had a diploma, which allowed her to teach French, but she devoted herself to caring for their families. Raised in a conservative, disciplined and intellectual atmosphere, the boy loved to read, and outside the home is actively spent time: swimming, sailing, skating, which greatly encouraged in his family.
. Shortly after the family moved in Bilthoven, a suburb of Utrecht, Nicholas went to primary school
. In twelve years he began to study in a municipal school in Utrecht, where the emphasis was on the humanities, and students preparing for university. Almost all of his teachers have doctorates. His penchant for natural science emerged only in recent school years, when he began to study the foundations of physics and chemistry.
In 1938. Bloembergen entered the University of Utrecht to study physics. 'The choice of physics - he wrote later - was probably caused by the fact that this subject seemed to me the most difficult'. After the occupation of Germany, the Netherlands in 1940. Many faculty members were fired or caught by the Gestapo. Nevertheless, Bloembergen received the equivalent of a master's degree in 1943, just before the Nazis closed the university. During the next two years he hid from the Nazis. By the end of the war, Europe was devastated, so that B. for further education had to go to American schools, and he was admitted to graduate school at Harvard University in 1945. Buoyed by his family, he went there classes, attending lectures of leading physicists such as Julius C. Schwinger and John X. Van Vleck.
In just six weeks before the arrival of B. in the United States Edward M. Purcell and his two colleagues discovered nuclear magnetic resonance (NMR) - absorption and emission of a nucleus of high frequency electromagnetic energy associated with the nuclear spin. Kernel behaves like a spinning gyroscope. Since it is positively charged, its motion is equivalent to electric current, which generates a magnetic field similar to field created by currents in the windings of the electromagnet. Nuclear Magnetism, like any magnetism has magnitude and direction, and also interacts with external electromagnetic fields.
As graduate Purcell B. helped develop the first NMR instruments and with Purcell, and RV. Pound in 1948. published an important article on the relaxation effects in NMR nuclear magnetic orientation of the return to a previous state after the excitation of electromagnetic fields from an external source. This return is caused by the surrounding structure and depends on the details of this structure. Many of these materials included in a doctoral dissertation BA, which he presented at Leiden University in the same year, and he was receiving a stipend for research work, he moved there in 1947. and began working in the laboratory behalf of the Netherlands physicist Kamerlingh Onnes.
Returning to the United States in 1949, B. was elected a member of a very prestigious Harvard Alumni Society. He began there as an associate professor in 1951, full professor in 1957, professor of physics in 1974. and university professor in 1980
In 1953, Mr.. Charles G. Charles Townes, along with two colleagues experienced at Columbia University maser (an acronym from the English expression, . meaning 'microwave gain through stimulated emission'), . device, . giving intense, . narrow, . monochromatic beam of microwaves,
. Stimulated (induced) radiation has been predicted by Albert Einstein in 1917. on the basis of quantum theory and model of the atom proposed by Niels Bohr, according to which negatively charged electrons revolve around the positively charged dense central core. The motion of electrons is limited to a few orbits (or energy levels), and they can move from a lower to a higher level, aroused by the absorption of electromagnetic radiation. Max Planck showed that this radiation consists of discrete portions, now called photons, and that its frequency is proportional to the photon energy. Photons absorbed by an atom has an energy equal to the difference between the two characteristic energy levels of the atom. The excited electron is quickly transferred back to a lower level, emitting a photon corresponding to the energy (and corresponding frequency) equal to the difference between the two levels. Typically, photons are emitted at random times and completely unrelated phases Einstein showed, . that if the atoms (or molecules, . which also have energy levels, . but is more sophisticated atoms) could bring up to a certain energy level and keep it, . the radiation with matching energy (frequency) of photons would cause their simultaneous transition to a lower level,
. Suitable frequency and photon energy should correspond to the difference between two energy levels. The result should be an avalanche selection in the same time, the photons with the same frequency and same phase (position in the vibration cycle), generating powerful coherent (all in one phase) radiation. As a relatively small magnetic signal is relatively large signal at the same frequency at the output, the result is an amplification of stimulated emission.
. In maser Townes used gaseous ammonia with two particular energy levels, which corresponded to the difference of photons with frequency radio spectrum
. When B. wrote in 1956. his work on magnetic resonance, he proposed to base the development of maser principle of three levels, allowing use of solid materials, such as crystals. Under this scheme, the crystal, filed under the influence of submitting the appropriate radiation frequency, passes to the uppermost of the three specific energy levels. As a result of a natural exit from the excited state will transition to the intermediate level as a source of stimulated emission. Radiation with a frequency corresponding to the difference between the two lowest levels is desired then the emission of radiation. Arthur L. Schawlow later called scheme B. first practically useful masers.
The first device, which gives the induced (stimulated) emission of visible light, was built in 1960. American physicist Theodore Maimana and became known as 'laser' (l - from the English word "light" - 'light'). In the same year, Arthur Schawlow and other physicists also built lasers.
During the same period and the maser and laser have been independently created Nikolai Basov and Aleksandr Prokhorov. In 1965, Mr.. Arnaud A. Penzias and Robert Y. Wilson used a solid-state maser based on the ruby crystal to detect the cosmic microwave background radiation, the balance of a hypothetical 'big bang', in which our universe was born.
B. known as one of the founders of nonlinear optics, the general theory of interaction of electromagnetic radiation with matter, more general than that which was formulated in the XIX century. James Clerk Maxwell. According to Maxwell's theory, the impact on the substance of the visible light or any other form of electromagnetic radiation is directly proportional to the intensity of radiation.
In 1962. B. with three colleagues published the general theory of nonlinear optics, which was subsequently considerably expanded. He made a significant contribution to the development of lasers, . showing, . that by virtue of the laws of nonlinear optics in the laser can appear harmonics, . multiples of the fundamental frequency and similar overtones in the sound, . happen as a result of the radiation beams of energy higher frequency,
. Describing the alleged interaction of three laser beams, which forms a fourth beam, whose frequency can be controlled with high accuracy, B. laid the theoretical basis for creating a custom laser. Using tunable lasers, other researchers, including the need to allocate Schawlow, have developed sophisticated techniques of laser spectroscopy, which provided new, very detailed information about the structure of atoms and molecules. In spectroscopy, laser beams excite the atoms, converting them to energy levels higher than the lowest (basic) state. Noting what the frequency is preferably absorbed or emitted, spectroscopists can determine the characteristic energy levels, ie. structure of the material studied. Precise knowledge of the frequency of the beam, which provides a monochromatic (single frequency) nature of laser light, and the ability to precisely adjust the frequency of the various energy levels allow for a more thorough analysis.
. 'For contributions to the development of laser spectroscopy' B
. Schawlow and divided among themselves in 1981. half of the Nobel Prize in Physics. The other half was awarded Kai Siegbahn for electron spectroscopy using x-ray. In conclusion, Nobel lecture B. pointed out some applications of nonlinear optical processes, including development of optical communication systems, time and linear metrology, and the collection of information.
At a conference of physicists in the Netherlands in 1948. B. met Hubert Delianya Brink, a native of Indonesia, who studied medicine. She followed him in the next year in America on student exchange, and B. he proposed to her on the first day after her arrival. They married in 1950, they had a son and two daughters. He became an American citizen in 1958. 'Good old Dutch gentleman', as described one of his colleagues, B. likes to play tennis, make walking and skiing family lives in Lexington (Mass.).
In addition to the Nobel Prize, B. Oliver Buckley won the American Physical Society (1958), . Morris Liebmann Award of the Institute of Radio Engineers (1959), . Medal Stuart Ballantyne Franklinovskogo Institute (1961), . National Medal 'For his scientific achievements' of the National Science Foundation (1974) and Frederic Ives Medal of the American Optical Society (1979). He is a member of the American Academy of Arts and Sciences, . U.S. National Academy of Sciences and the Dutch Royal Academy of Sciences.,