(where N,M are relatively prime numbers) into 3 desired domains. The design of spectral DOEs is based on a non-linear phase transformation by the law of color-separation grating.
Half-tone
image of a DOE relief to focus the wavelength
l0 = 0,525 mm,
l+1
= 0,42 mm, l-1
= 0,7 mm (N
= 4, p = 1)
into a segment, four spots and four segments;
Intensity distributions produced after a plane illuminating beam
passes through the DOE:
l0 (à), l+1
(á), l-1 (â).
a) 
b)
c) 
Publications:
L.L.Doskolovich Design of diffractive optical elements to separate and focus
the light of different wavelength, Computer Optics, 1998,18, pp. 16-24.