Maximizing transmittance in two-photon 3D printed materials for micro-optics in the visible.

We characterize three commercial resins suitable for three-dimensional two-photon printing of mm volume micro-optical components for visible light - IP-S, IP-n162, and IP-Visio - under different print modes and post-processing conditions. Due to the combination of cured resin absorption and bulk scattering, we find a maximum total printed thickness of 4 mm (or greater) for at least 50% transmittance of red light, up to 2 mm for green light, and large maximum thickness variation for blue light (0.1 to 1 mm).