Nanoimprinting of Mesoporous Titania: A Facile Route to Visible-Wavelength Optical Devices

We demonstrate nanoimprinting of refractive index to pattern mesoporous titania, enabling mechanically tuned ∆ n for visible-wavelength diffractive and resonant optical devices. This scalable, lithography-free method supports high-fidelity metasurfaces for sensing, structural color, and photonics applications.