Polarization Holographic Monitoring for Laser Treatment Diffractive Optical Elements and Metasurfaces Fabrication in Functional Materials Photonics

Abstract: We demonstrate the application of a custom-built polarization holographic microscope (PHM) for comprehensive characterization of laser-fabricated and self-assembled optical elements. We investigate two distinct material platforms: silver-doped zinc oxide (ZnO:Ag) sol–gel films structured by femtosecond direct laser writing, and self-assembled torons, namely soft topological solitons, in chiral nematic liquid crystals (LCs). The PHM enables single-shot, multi-wavelength (450, 532, 660 nm) reconstruction of the full Jones matrix, providing complete amplitude, phase, and polarization information. For ZnO:Ag films, we show that laser writing induces programmable dichroism and birefringence, characterized by a spectrally dependent phase shift (e.g., +π/4 at 450 nm and –π/8 at 660 nm between orthogonal Jones matrix components), establishing a foundation for all-dielectric metasurfaces. For torons, PHM analysis of torons in 25 µm LC cells reveals complex ring structure of the corresponding phase and light intensity distributions and confirms the robustness of their optical functions (e.g., vortex generation) across the visible spectrum.