Focus shaping via flat optics

Complex three-dimensional (3D) focus shaping plays a critical role in applications ranging from laser-based manufacturing to super-resolution optical microscopy. Traditional methods typically rely on multiple components (e.g., phase plates and objective lenses), which can be bulky and complex. In this work, we leverage inverse design to develop a single, patterned “flat optic” capable of producing precise 3D focus profiles. We demonstrate extended depth-of-focus spots with both Gaussian and square top-hat beam shapes, along with 3D hollow beams and other custom designs. These flat optics enable efficient laser marking, glass scribing, and laser cutting, and they function across all power levels and pulse widths—from continuous-wave (CW) to femtosecond—highlighting their versatility for a broad range of laser-based processes.