Review of vat photopolymerization 3D printing of photonic devices

Vat photopolymerization (VP) 3D printing, a subset of additive manufacturing, is renowned for its capability to create intricate structures with high precision, particularly useful in optical applications. The process involves using photosensitive resins cured layer by layer through various light-curing technologies like Stereolithography (SLA), Digital Light Processing (DLP), Two-Photon Polymerization (TPP), Continuous Liquid Interface Production (CLIP), and Liquid Crystal Display (LCD). Each technique offers unique advantages in terms of speed, resolution, and material compatibility, with TPP providing the highest resolution. This review explores the diverse applications of VP 3D-printed optical components, including lenses, waveguides, optical gratings, resonators, metamaterials, sensors, and actuators, demonstrating their significant role in advancing optical technology and innovation. Challenges in material selection, post-processing requirements, size limitations, and support structures are discussed, alongside potential future research directions. These include developing advanced photopolymer materials with enhanced optical properties, hardware improvements for higher resolution and multi-material printing, and quality assurance measures for ensuring optical precision. Despite some limitations, VP 3D printing presents a promising avenue for the rapid prototyping and production of complex, multifunctional optical devices, marking a significant stride in optical manufacturing and technological development.