Precise light control in highly tilted geometry by freeform illumination optics

The control of light propagation in highly tilted geometry by freeform illumination optics has numerous applications. However, difficulties associated with the tailoring of freeform surfaces in tilted geometry significantly limit the scope of applications. Here, for the first time, to the best of our knowledge, we develop a general formulation for designing freeform illumination optics in highly tilted geometry. The numerical and experimental results show that when a precise control of light propagation is achieved, the freeform lenses are highly efficient and can significantly reduce glare and light trespass.