Phase diffractive optical elements for the Hadamard expansion

An iterative method in this paper reports the design of a phase diffractive optical element (DOE) that has a transmission function in the form of a linear combination of a finite number of Hadamard functions with different carrier spatial frequencies. If such a DOE is coupled with a spherical lens and illuminated by the light wave, the light intensities in desired points will be proportional to the squared modules of the expansion coefficients of that light field in terms of the Hadamard basis. It is found that 80% of the incident light energy is accounted for by the formation of the desired coefficients.