Funnel-based biomimetic volume optics

We demonstrate the use of three-dimensional funnel index of refraction patterns analogous to those of retinal Müller cells as support for tunable and multi-functional volume optical component miniaturization and integration. Our experiments in paraelectric photorefractive crystals show how a single funnel can act both as a waveguide and a tunable focusing/defocusing micro-lens. Pairing multiple funnel patterns, we are also able to demonstrate ultra-compact tunable beam-splitting, with distinct guided output modes in under 1mm of propagation. © 2012 Optical Society of America.