Henry R. Hirsch."October 15, 1961." "...presented to the Department of Physics, Massachusetts Institute of Technology, in partial fulfillment of the requirements for the degree of Doctor of Philosophy." "Reprinted from Journal of the Optical Society of America, vol. 51, no. 11, 1192-1202, November, 1961."Army Signal Corps Contract DA36-039-sc-78108, Department of the Army Task 3-99-20-001 and Project 3-99-00-000.