High-Transparency 3D Micro-Optics of Hybrid-Polymer SZ2080™ Made via Ultrafast Laser Nanolithography and Atomic Layer Deposition

This is the authors' abstract. We don't add key points for this paper.

Laser Direct Writing (LDW) allows for the fabrication of complex free-form structures, particularly advantageous in micro-optic applications when used in conjunction with high-performance polymers, such as SZ2080™. Nonetheless, high-complexity and integrated micro-optical elements often manifest multiple interfaces, resulting in increased Fresnel reflection losses. While conventional physical vapour deposition processes are usually employed in the manufacture of high-precision optics, such methods are incapable of producing uniform coatings on micrometer scale complex free-form structures. Atomic Layer Deposition (ALD) is an alternative highly flexible coating process, able to coat intricate geometries down to nano-scale. We propose the use of LDW in conjunction with ALD in the production of highly efficient anti-reflective (AR) coated functional free-form sub-100 μm micro-optic elements - multi-layer platforms and triplet objectives. Low-temperature deposition of aluminum oxide and titanium oxide AR coating proved to be compatible with SZ2080™ polymer structures, as no loss of optical function was observed. In addition, a substantial increase in transmittance, up to 99.9% per interface, is seen. Such findings prove suitable for use in highly efficient compound micro-lens arrays, greatly integrated solutions, and low-loss photonic components making them readily available for Photonic Integrated Circuits (PICs).