Two-photon polymerization for random rough surface preparation

A typical tool to characterize diffuse materials is the determination of the scattering and absorption coefficients. Most of these evaluation methods consider optically smooth surfaces between the investigated and the surrounding medium. However, realistic surfaces generally show a distinct roughness, which influences the reflected and transmitted light of the investigated material. Hence, it is necessary to understand the optical behavior of these rough surfaces. We present a method for the preparation of such optically rough surfaces using two-photon polymerization. The properties of these rough surfaces can be precisely adjusted within a range of a few hundred nanometers. Additionally, an easy-to-use preparation method is shown to compensate for reflections from the backside of the used substrate. Hence, these surfaces can be used for measuring the reflectance leading to a better understanding of the scattering behavior of rough surfaces and their influence on the determination of the optical properties of turbid media.

Automated summary

A common tool for studying and characterizing diffuse materials is the calculation of scattering and absorption coefficients. However, realistic surfaces often have distinct roughness, which affects the reflection and transmission of light. This study presents a method for creating optically rough surfaces using two-photon polymerization, allowing for precise adjustment of these surfaces within a few hundred nanometers. Additionally, a simple preparation method is shown to compensate for reflections from the backside of the substrate, enabling the measurement of reflectance and a better understanding of the scattering behavior of rough surfaces and their impact on determining optical properties of turbid media.