UV to NIR optical properties of IP-Dip, IP-L, and IP-S after two-photon polymerization determined by spectroscopic ellipsometry

The polymers IP-Dip, IP-L, and IP-S are among the most commonly used photo-resists employed for the rapid prototyping of optical components using two-photon polymerization. Despite the widespread use of these polymers, measured data on their optical properties is scarce. Recently, the refractive index n of these polymers has been determined in the visible and near-infrared spectral range. However, the accurate optical properties including extinction coefficient κ in the ultraviolet spectral range have not been reported yet. Here we report on accurate, ellipsometric measurements of the complex dielectric functions of two-photon polymerized IP-Dip, IP-L, and IP-S in the spectral range from 210 nm to 1500 nm. Model dielectric functions composed of oscillators with Lorentz, Gaussian, and Tauc-Lorentz broadenings are presented for all investigated polymers.