[2] LI Y, WOLF E. Focal shift in diffracted converging spherical waves[J].Opt.Commun,1981,39(4):211-215.
[3] CARTER W H. Focal shift and concept of effective Fresnel number for a Gaussian laser beam[J]. Applied Opt,1982,21(11): 1989-1994.
[5] SELF S A. Focusing of spherical Gaussian beams[J]. Applied Optics,1983,22(5):685-661.
[6] GIVENS PARKER M. Focal shift in diffracted converging spherical waves[J].Opt.Commun,1982, 41(3):145-148.
[9] SHEPPARD C J R, TOROK P. Dependence of Fresnel number on aperture stop position[J]. J.Opt.Soc.Am.A, 1998, 15(22):3016-3019.
[10] WENZEL R G. Effect of the aperture-lens separation on the focal shift in large-F-number systems[J]. J.Opt.Soc.Am.A,1987,4(2):340-345.