Physics Dept Seminar

February 17, Monday

Additive Manufacturing of Infrared and THz Metamaterials: Towards Emergent Polarization-Discriminating Imaging Modalities

Prof. Tino Hofmann

Univ. of North Carolina - Charlotte

(Optics, Host: Benjamin Thomas)

Time: 11:45 am - 12:45 pm with 11:30 am teatime

Room: ECE 202

Additive manufacturing techniques using single- and two-photon polymerization have made substantial progress in recent years. Achievable dimensions to polymerize discrete, three-dimensional structures now range from the scale of tens of micrometers to a few hundred nanometers for single- and two-photon polymerization, respectively. By leveraging the wide transparency windows of the photopolymers in the THz and infrared spectral ranges, these techniques open a new avenue for the fabrication of novel optical materials with engineered optical properties, facilitating their integration into optical components and devices.

However, while the fabrication processes have made substantial advancements the focus is often on the mechanical properties of the micro- and nanostructured objects. The optical characterization of the materials is frequently lacking behind and the opportunity for the fabrication and rapid prototyping of optical elements is not fully recognized.

This presentation will review the advancements in the precise optical characterization of polymers that are compatible with single- and two-photon polymerization processes, specifically within the infrared and terahertz spectral ranges. It will be demonstrated how these polymerization processes can be used for the rapid prototyping of optical elements including components with tunable optical properties. The fabrication of functional optical elements with mm-scale dimensions and critical features on the micrometer and nanometer scale now enables real-time Mueller matrix measurements in the THz spectral range with extremely high spectral resolution. Due to this dramatic improvement of the measurement time, it is now feasible to combine Mueller matrix ellipsometry with single-pixel imaging techniques. We will explore how this approach would enable the extraction of spatially and polarization-sensitive Mueller matrix information that remains inaccessible by contemporary experimental techniques.