Wavefront Sensor for Laser Beams Based on Reweighted Amplitude Flow Algorithm

Abstract: We present a reference-free computational wavefront sensor based on binary amplitude modulation and phase retrieval. The method employs Digital Micro-mirror Device as a programmable amplitude modulator and reconstructs the complex optical field from multiple far-field intensity measurements using the Reweighted Amplitude Flow algo-rithm with Optimal Spectral Initialization. Unlike classical pupil-plane wavefront sen-sors, the proposed architecture does not include any wavelength-specific optical elements, enabling straightforward adaptation across a broad spectral range. The achievable spatial resolution of the reconstructed wavefront is scalable with the modulator resolution. We experimentally demonstrate wavefront reconstruction at 650 nm and at 2116 nm, where commercial wavefront sensors are not widely available. The reconstructed wavefront is validated against a commercial lateral shearing interferometer at 650 nm, and the method is further integrated into a closed-loop adaptive optics system using a deformable mirror. The approach is particularly suited for applications requiring high spatial resolution and large dynamic range in slowly varying or quasi-static laser fields, where computational reconstruction speed is not of the primary concern.