Writing Chiral Nanostructures Inside Silica with Polarization-Engineered Bessel Beams

The fabrication of chiral optical elements is a key element in optics and photonics to enrich the portfolio of tools enabling the control or detection of atoms, molecules and solids with light. Pioneering work has already demonstrated that ultrafast laser written nanogratings in silica can exhibit chiral optical properties [1]. However, the tailoring of these chiral optical properties is highly restricted when writing with conventional femtosecond (fs) Gaussian beams because of the relatively small optical thickness. Recently, a multi-layer fs laser writing strategy has demonstrated new opportunities to reach high chiroptic properties [2].