https://doi.org/10.1051/epjconf/202430911007
Holographic fabrication of reconfigurable diffractive elements
1 Physics Department “E. Pancini”, University of Naples Federico II, Complesso Universitario di Monte Sant’Angelo, via Cinthia 21, 80126, Naples
2 Department of Chemical Sciences, University of Naples Federico II, Complesso Universitario di Monte Sant’Angelo, Via Cintia, 80126 Naples
* Corresponding author: stefanoluigi.oscurato@unina.it
Published online: 31 October 2024
The fabrication of Diffractive Optical Elements (DOEs) involves the analog patterning of material surfaces on the scale of light wavelength. This typically requires multi-step lithographic processes. Differently from the photoresists of standard lithography, thin films of amorphous azobenzene-containing polymers (azopolymers) can directly produce a structured surface using a single irradiation step with structured light. The resulting surface reliefs can be used directly as planar phase-modulating DOEs without the need for any post-exposure process. Additionally, the surface geometry and its optical functionality can be reconfigured at will. Here, we demonstrate reprogrammable and ready-to-use azopolymer diffractive gratings, lenses, and holographic projectors, produced by grayscale digital holographic patterns. By exploiting the all-optical scheme based of computer-generated holography, the diffraction behavior of the DOEs is optimized during the developing of structured surfaces. Full all-optical reconfigurability of the fabricated devices is also achieved. Our approach provides a versatile, efficient, and all-optical reversible fabrication framework for DOEs, making it a promising option to overcome the demanding, cumbersome, and irreversible fabrication processes typically involved in the realization of planar diffractive optical devices.
© The Authors, published by EDP Sciences, 2024
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
