Direct calibration of phase-only spatial light modulators using an array of binary phase Fresnel zone plates

In this manuscript, we propose an all-diffractive, direct method for calibrating the phase response of liquid crystal on silicon spatial light modulators. This approach uses a single-phase mask comprising an array of binary phase Fresnel lenses, each of which samples a specific gray level across the full available range. Consequently, the complete phase calibration curve can be derived from a single recorded irradiance pattern, significantly reducing acquisition time and experimental complexity compared to conventional sequential phase calibration techniques, which require repeated measurements and additional optical components. The phase calibration method demonstrates accurate results under continuous-wave laser illumination, and remains effective under periodic laser power oscillations (~6.8 Hz). Thanks to its efficiency and adaptability, it enables rapid calibration and optimization under varying illumination conditions, making it particularly valuable for multispectral imaging and optical metrology applications.