Kepler Microlens Array for Directional-emitting Micro-LED

In the field of naked-eye 3D display imaging, achieving precise and efficient light control is essential. This paper proposes a microlens array (MLA) designed based on Kepler structures to enhance light steering in a micro-LED-based naked-eye 3D display, fabricated by two-photon polymerization. The microlens array enables directional light deflection at angles of 9°, 17°, and 29° for micro-LED pixels measuring 26 μm, achieving optical efficiencies of 62.36%, 58.78%, and 49.28%, respectively. A comparison between geometric optics ray tracing and Finite-Difference Time-Domain (FDTD) simulation shows that the deflection angles are in good agreement. Experimental results indicate that the light deflection angle of the microlens array fabricated through two-photon polymerization is 27.9°, closely matching the results of theoretical simulations.