K. Strehl, Z. Instrumentenk. 22, 213 (1902).
A. Maréchal, Rev. Opt. 26, 257 (1947).
3 A. Maréchal, thesis, University of Paris (1948). See also: M. Born and E. Wolf, Principles of Optics (Pergamon Press, London, 1965), 3rd ed., p. 468; E. L. O'Neill, Introduction to Statistical Optics (Addison-Wesley, Publ. Co., Reading, Mass., 1963), p. 62.
The shape of the pupil periphery for an extra-axial pencil was first approximated by a best-fitting ellipse, and then scaled to correspond to a unit-circle. W. B. King, Appl. Opt. 7, 197 (1968).
H. H. Hopkins, Proc. Phys. Soc. (London) B, 70, 1002 (1957).
Here we intend to investigate the Strehl ratio under the condition that the secondary spherical aberration coefficient is fixed, while relative amounts of primary spherical and defocusing are variable. For the even-aberration case, the scaling parameter ƒ is numerically equal to W60.
R. Richter, Z. Instrumentenk. 45, 1 (1925); E. H. Linfoot, Opt. Acta 10, 84 (1963).
This special property also served to check the accuracy of the numerical-integration technique over the range of aberration values employed. Using M=1 and N=10, we have found that the numerical results for the Strehl ratio corresponding to these two cases agree to the seventh decimal place; the respective phases are, of course, different.
W. B. King, Appl. Opt. 7, 489 (1968); R. Barakat and A. Houston, J. Opt. Soc. Am. 55, 1142 (1965).
H. H. Hopkins, Optica Acta, 13, 343 (1966).