X ray microcopy of polymer photonic structures.

The last decades were beneficial for nanofabrication techniques but validation of the increasingly complex nano-structures became more challenging. Recent advancements of X-ray tomography permit 3D reconstruction down to 20 nm resolution. We propose the use of this non-invasive technique to quantify the fabrication quality of 3D structures made with direct laser writing (DLW). The comparison of X-ray density function with the designed fabrication density map brings into light information of how polymerization takes place throughout the fabricated volume and also gives the opportunity to estimate the impact on the optical response of such media.