Karl Karlovich Rebane (born 11.04.1926) is a Soviet physicist, an academician of the Academy of Sciences of the Estonian SSR (1967) and its president (from 1973), and a corresponding member of the USSR Academy of Sciences (1976). He was born in Pärnu. He graduated from Leningrad University (1952). In 1956-64 he worked at the Institute of Physics and Astronomy of the Academy of Sciences of the Estonian SSR, in 1964 —68 he was academician-secretary of the Division of Physical, Mathematical and Technical Sciences, and in 1968 —73 vice-president of the Academy of Sciences of the Estonian SSR. In 1973-76 he was director of the Institute of Physics of the Academy of Sciences of the Estonian SSR. From 1968 he has also been professor at Tartu University.
His work concerned the spectroscopy of crystals (the theory of the spectra of crystals activated by impurity atoms and molecules, the theory of the influence of lattice vibrations and vibrational relaxation on electronic and intranuclear transitions in the particles forming the crystal, and the development of a theory of the secondary emission of activated crystals). He predicted and detected hot luminescence of crystals (1968).
He proposed using simple molecules and molecular ions embedded in the crystal lattice as sensitive probes for a detailed experimental study of the interaction of an impurity with the crystal and of the properties of the crystal. He made
accurate measurements of the spectra of chlorophyll molecules frozen in solid-state matrices.
P. N. Lebedev Gold Medal (1981).