Freeform optics design based on ray mapping methods

Manipulating flux transportation of optical fields holds great promise across various kinds of applications, encompassing laser micro-processing, optical trapping, microscopic imaging, and illumination engineering. In recent decades, freeform optics, lauded for its capacity to efficiently control the wavefronts of optical beams with high design freedom, has garnered significant attention as a potent tool for shaping light. Nevertheless, the constraints imposed by geometric optics pose a further limitation on FOEs, particularly in their ability to sculpt coherent light, such as laser beams, as these are particularly susceptible to diffraction effects. Within the context of this study, we propose a design paradigm that harnesses freeform optics to craft light trajectories in three dimensions. This approach inherently gives rise to caustics, which are singularitie which are singularities within the realm of flux transfer in geometric optics. Crucially, our proposed method yields the capability to generate sharply defined light patterns, empirically giving better results for mitigating diffraction effects in contrast to previous design methodologies, which is observed by experiments.