Non-iterative heterogeneous phase zoning enabling controllable intensity and morphology in multi-focus array...

This study introduces a non-iterative heterogeneous phase zoning (NHPZ) method to control multi-focus arrays with tailored intensity distributions and focal spot morphologies. Leveraging vectorial diffraction theory, we derive a phase factor expression that governs spatial displacement control for focal points. The pupil plane is divided into sector-shaped zones, with phase factors adjusted to achieve precise control over individual focal spot intensity and morphology. We explore the relationship between phase zone size and focal intensity and present strategies for modulating intensity in multi-focus arrays. Numerical simulations and experiments validate the method's effectiveness in generating and modulating multi-focus arrays with Gaussian, vortex, Bessel, and Airy beam structures. Additionally, we demonstrate the application of the NHPZ method in femtosecond laser direct writing (TPP-DLW), successfully fabricating micro/nanostructures with controlled linewidths and intensity distributions. This approach provides an efficient and precise solution for overcoming intensity inhomogeneity in multi-focus parallel fabrication, with applications in micro/nano fabrication, optical sensing, and imaging.