3D Printing of Glass Imaging Optics with High Precision by Liquid Silica Resin

3D printing of optics has gained significant attention in the optical industry, but most of the research have been focused on organic polymers. In contrast, 3D printing inorganic glass has been achieved by filament, laser sintering, and vat photopolymerization methods, but burning out organics and sintering during densification gives rise to shrinkage, surface distortions, and limited quality. In order to attain optical quality suitable for micro-optics suitable for imaging, we developed a solvent-free, liquid silica resin (LSR) with minimal organics to achieve higher curing speed, better mechanical properties, lower thermal treatment temperature with no sintering required, reduced shrinkage, and, ultimately, glass optics with good surface quality. A two-photon polymerization process was utilized to print lenses from the LSR with flat, spherical, aspherical, freeform, and discontinuous surfaces with good surface shape and quality for imaging applications. Optical systems (e.g. micro-objective and micro-spectrometer) with multiple optical elements have also been printed and evaluated for imaging applications. Most importantly, we have also fabricated the micro-sized Alvarez lens pairs with moveable components. This study has paved the path for low-cost fabrication of complex glass optical systems for imaging applications.