Soft Matter Macro and Micro-Photonics workshop

Holographic photomorphing of polymer surfaces for reprogrammable diffractive optics

Stefano Luigi Oscurato

Physics Department “E. Pancini”, University of Naples Federico II, Complesso Universitario di Monte Sant’Angelo, via Cinthia, 80126, Naples, Italy.
stefanoluigi.oscurato@unina.it 

Light-induced photomorphing of azobenzene-containing polymer films enables the direct formation of micro- and nanoscale surface reliefs through a non-destructive and fully reprogrammable mass transport process. This light-responsive behavior turns a soft material surface into an active photonic device, in which optical functionality is encoded directly into surface topography. Because the same film can be written, erased, and reshaped in place with a geometry that directly reflects the full vectorial structure of the illuminating light, these materials offer a compelling route toward reprogrammable miniaturized diffractive optics.

In this talk, I will show how holography can be used to control this photomorphing process with high spatial fidelity by engineering the intensity and polarization structure of the writing beam. Using computer-generated holography and digital polarization control with spatial light modulators, azopolymer surfaces are structured into reprogrammable gratings, diffractive lenses, optical Fourier surfaces, and holographic projectors. Beyond demonstrating current device concepts, I will discuss how holographic photomorphing in these materials can define a broader framework for soft-matter photonics, in which light, structured across multiple degrees of freedom, becomes the only required lithographic tool. Within this picture, illumination alone governs fabrication, optical functionality, and post-fabrication reconfiguration, opening new directions for adaptive, lightweight, and programmable photonic systems.