The design of diffractive phase elements (DPE's) for generating color
pseudo-nondiffracting beams (PNDB's) in a multiple-wave illuminating s
ystem by the conjugate-gradient method is described. The axial-intensi
ty distributions for dual-color PNDB's generated by the DPE's are show
n. The color PNDB's behave as segmented axial-intensity distributions;
in each of segments only one color persists. The sequence of waveleng
th components in the color PNDB's can be arbitrarily preset. Three-dim
ensional plots of a dual-color PNDB indicate the characteristics of a
beam with high transverse resolution. (C) 1998 Optical Society of Amer
ica.