Fig. 1. Experimental setup. At, variable attenuator; P₁, P₂, P₃, linear polarizers; L₁, L₂, convergent lenses; QWP, quarter-wave plate; SF, spatial filter; Ap, circular aperture.

Fig. 2. Binary phase grating. (a) Normalized intensity of diffraction orders versus phase level; (b) experimental diffraction patterns for different phase values.

Fig. 3. Sinusoidal phase grating. (a) Normalized intensity versus parameter a; (b) experimental diffraction patterns.

Fig. 4. Gori’s optimum triplicator. (a) Phase profile for a = 1, a = 2.65, and a = 8; (b) theoretical and experimental normalized intensity of the 0th and ±1st orders versus a; (c) experimental diffraction patterns for different values of a.

Fig. 5. Quantized phase profile. Inset, for N = 20 versus Gori’s.

Fig. 6. Calculated diffraction efficiency of the quantized triplicator as a function of N. (a) η_0±1; (b) η_±2 and η_±3; (c) experimental diffraction patterns with N = 2, 3, 5, and 20.

Fig. 7. (a) Illustration of the gray-level image addressed to the SLM and (b) the corresponding experimental diffraction patterns for a uniform phase, a positive and a negative blazed gratings, and the random triplicator generated by randomly addressing to 4 × 4 macropixels the phase of either the uniform grating or that of the positive or the negative blazed grating.