Bell Labs

About: Bell Labs is a based out in . It is known for research contribution in the topics: Laser & Optical fiber. The organization has 36499 authors who have published 59862 publications receiving 3190823 citations. The organization is also known as: Bell Laboratories & AT&T Bell Laboratories.

Electronic Polarizabilities of Ions in Crystals

Abstract: A set of electronic polarizabilities has been obtained from a least-squares fit of experimental refraction data using simple additivity and a Lorentz factor of $\frac{4\ensuremath{\pi}}{3}$. Except for the fluorides, the electronic polarizability values of the alkali-halide crystals calculated from this set agree with the experimental data within 3 percent. Similar least-squares fits were attempted with various values of the Lorentz factor, the best fit being obtained for $\frac{4\ensuremath{\pi}}{3}$. On the basis of $\frac{4\ensuremath{\pi}}{3}$, the additivity assumption and the alkali-halide set, polarizabilities have been obtained for other ions. The best values for the sodium $D$ line in ${\mathrm{A}}^{3}$ are ${\mathrm{Li}}^{+}$ 0.03, ${\mathrm{Na}}^{+}$ 0.41, ${\mathrm{K}}^{+}$ 1.33, ${\mathrm{Rb}}^{+}$ 1.98, ${\mathrm{Cs}}^{+}$ 3.34, ${\mathrm{F}}^{\ensuremath{-}}$ 0.64, ${\mathrm{Cl}}^{\ensuremath{-}}$ 2.96, ${\mathrm{Br}}^{\ensuremath{-}}$ 4.16, ${\mathrm{I}}^{\ensuremath{-}}$ 6.43, ${\mathrm{Ca}}^{++}$ 1.1, ${\mathrm{Sr}}^{++}$ 1.6, ${\mathrm{Ba}}^{++}$ 2.5, ${\mathrm{O}}^{\ensuremath{-}\ensuremath{-}}$ 0.5-3.2, ${\mathrm{S}}^{\ensuremath{-}\ensuremath{-}}$ 4.8-5.9, ${\mathrm{Se}}^{\ensuremath{-}\ensuremath{-}}$ 6.0-7.5, ${\mathrm{Te}}^{\ensuremath{-}\ensuremath{-}}$ 8.3-10.2, ${\mathrm{Ag}}^{+}$ 2.4, ${\mathrm{Cu}}^{+}$ 1.6, ${\mathrm{Cu}}^{++}$ 0.2, ${\mathrm{Zn}}^{++}$ 0.8, ${\mathrm{Cd}}^{++}$ 1.8, ${\mathrm{Ge}}^{4+}$ 1, ${\mathrm{Sn}}^{4+}$ 3.4, ${\mathrm{Pb}}^{++}$ 4.9. Values represented by a spread indicate ions that cannot be treated additively.

Normal mode determination in crystals

Abstract: The group theoretical methods by which the symmetries of normal modes in crystals may be determined are outlined, and a series of tables are presented to facilitate rapid determination of the selection rules for vibrational transitions. Emphasis is placed on the method of nuclear site group analysis in which the number of infrared and Raman active modes of each symmetry may be obtained without detailed analysis of the symmetry elements in the crystallographic unit cell or the construction of tables. By using the tables presented here for most cases identification of the crystallographic space group is sufficient information to allow determination of the vibrational mode selection rules by inspection. Several examples are included in which crystals are analyzed by each of the methods.

Light waves in thin films and integrated optics.

Abstract: Integrated optics is a far-reaching attempt to apply thin-film technology to optical circuits and devices, and, by using methods of integrated circuitry, to achieve a better and more economical optical system. The specific topics discussed here are physics of light waves in thin films, materials and losses involved, methods of couplings light beam into and out of a thin film, and nonlinear interactions in waveguide structures. The purpose of this paper is to review in some detail the important development of this new and fascinating field, and to caution the reader that the technology involved is difficult because of the smallness and perfection demanded by thin-film optical devices.