By J. N. Hodgson (auth.)
The electromagnetic thought of Maxwell and the electron concept of Lorentz and Drude encouraged loads of experimental paintings at the optical houses of solids within the overdue 19th and early 20th centuries. The time used to be now not then ripe, besides the fact that, for basic growth during this box. The experimental ideas weren't on hand to provide appropriate specimens for optical measurements with good outlined constitution and purity. at the theoretical facet, the classical electron concept supplied just a very incomplete account of the interplay of sunshine waves with subject. The centre of curiosity in optical examine moved to atomic and molecular spectroscopy the place quantitative effects have been more straightforward to acquire. The quantum thought, beginning with Bohr's concept of 1913, supplied a hugely profitable foundation for the translation of the optical spectra of atoms and molecules. The present-day idea of the optical houses of solids relies at the quantum conception of electrons in solids, constructed from the early researches of Sommerfeld and Bloch, and the speculation of lattice vibrations originating within the examine by way of Born. The formal con nection among optical absorption and electron wave features in solids has been popular because the Nineteen Thirties however it is simply lately that electron power band calculations have completed adequate accuracy to make ecocnomic a comparability of experimental and theoretical effects. with out a few assistance from a theoretical band constitution calculation, it might be tough to make any growth with the in terpretation of an optical absorption spectrum.