3D printing of optical materials: an investigation of the microscopic properties

TL;DR

This paper explores the microscopic properties of 3D printed optical materials, focusing on how process variables affect uniformity and light propagation, using in-situ laser confocal microscopy and kinetic modeling.

Contribution

It introduces an in-situ experimental method and kinetic modeling to analyze and improve the optical quality of 3D printed structures.

Findings

Identified factors limiting light propagation in printed materials

Developed a real-time, microscale investigation method

Provided strategies to enhance optical properties

Abstract

3D printing technologies are currently enabling the fabrication of objects with complex architectures and tailored properties. In such framework, the production of 3D optical structures, which are typically based on optical transparent matrices, optionally doped with active molecular compounds and nanoparticles, is still limited by the poor uniformity of the printed structures. Both bulk inhomogeneities and surface roughness of the printed structures can negatively affect the propagation of light in 3D printed optical components. Here we investigate photopolymerization-based printing processes by laser confocal microscopy. The experimental method we developed allows the printing process to be investigated in-situ, with microscale spatial resolution, and in real-time. The modelling of the photo-polymerization kinetics allows the different polymerization regimes to be investigated and the influence of process variables to be rationalized. In addition, the origin of the factors limiting light propagation in printed materials are rationalized, with the aim of envisaging effective experimental strategies to improve optical properties of printed materials.