Freeform gradient-index optics for prescribed illumination

A new type of prescribed illumination optic is presented that leverages newly available freeform gradient-index (F-GRIN) media. Using F-GRIN to impart freeform optical influence, only plane-parallel surfaces are required, and by additive manufacturing, designs can directly incorporate gradient discontinuities. The design process is surveyed, and several designs are demonstrated for generating both binary and grayscale illumination targets from a point source. Fabricated designs are presented for the first time, verifying that F-GRIN optics present a flexible, new way of generating a prescribed illumination distribution.