Control of light’s spatial coherence via spatial light modulator

Reducing light coherence is no longer seen as a limitation but rather as a valuable feature in applications such as displays , holography, and optical communication. In these technologies, low spatial coherence reduces artifacts, improves brightness, and minimizes speckle formation. Rotating glass diffusers, lack precision and repeatability as they rely on mechanical adjustments. Our approach, based on a Spatial Light Modulator (SLM), eliminates these limitations by enabling dynamic and programmable control of spatial coherence. Using Laguerre-Gaussian beam, we reverse-engineer coherence effects by superposing amplitude-phase maps displayed continuously on the SLM. We extended this method to Hermite-Gaussian beams, demonstrating partial. We simulate the effect of rotating diffusers using vortex lattices, controlling parameters such as vortex number, lattice period, and topological charge. Our experimental setup validates these findings through single-shot and point-by-point measurements, confirming numerical simulations. This technique is scalable, tunable, and can be applied to digital micromirror devices, offering broad potential for integration with modern optical systems.