Fast and efficient optical field control via binary amplitude modulation: applications to optical holography and speckle customization

Abstract

Speckle patterns, which arise from the scattering of coherent light by disordered media, play a central role in applications such as imaging, sensing, and optical communication. However, controlling speckle patterns with both high speed and high efficiency remains a major challenge. Liquid crystal spatial light modulators provide precise phase control but operate at frame rates of only 50–100 Hz, while Digital Micromirror Devices (DMDs) can reach kHz speeds but typically suffer from low diffraction efficiency. This thesis introduces Diffuser-integrated Binary Amplitude Modulation (DiBAM), a framework that combines the kHz switching speed of DMDs with the strong mode mixing of a diffuser to enable rapid, efficient, and accurate speckle pattern engineering. Through purely binary amplitude modulation, DiBAM supports a wide range of wavefront-shaping applications, including point focusing, high-efficiency holography, and non-Rayleigh speckle customization. The diffuser ensures that each micromirror contributes to all output channels, enabling complex field synthesis with high modulation fidelity. Numerical and experimental demonstrations show that DiBAM achieves point focusing without phase modulators, surpasses state-of-the-art holographic methods in balancing efficiency and fidelity, and enables fast speckle customization with tailored intensity probability density functions. These findings establish DiBAM as a versatile, high-performance platform for next-generation adaptive optics and computational imaging.