1. T. W. Adair, III, E. J. Sharp, and C. F. Squire, J. Chem. Phys. 44, 3650 (1966).JCPSA60021-9606
2. C. A. Plint and L. W. Watson, Bull. Am. Phys. Soc. 11, 811 (1966).BAPSA60003-0503
3. L. Taurel and Girard‐Nottin, J. Phys. 27, 26 (1966).
4. The authors acknowledge discussions with J. L. Gammel concerning the theoretical interpretation. See also M. Born and E. Wolf, Principles of Optics (Pergamon Press, Inc., New York, 1959) Chap. 14.
5. A. Sommerfeld, Optics (Academic Press Inc., New York. 1954), p. 172.