Abstract

Exposing fused silica with a femtosecond laser below the ablation threshold leads to different types of microscale sized modifications. Among the taxonomy of modifications, the so-called ‘nanogratings’ [1] has gained particular attention because of its anisotropic nature consisting of self-organized nanoplanes, periodically distributed within the laser spot by a few hundreds of nanometers. Here we show that these nanogratings also exhibits unusual anisotropic elastic properties, very much alike a meta-crystal with a lattice parameter of a fraction of a wavelength. Such anisotropic nano-mechanical properties are particularly interesting for designing meta-materials with unconventional and tunable elastic properties. This for instance is particularly useful for achieving zero-stress zones, much like a ’cloaking’, to protect stress-sensitive zones for achieving optical functions such as waveguides or mechanical ones, like stress-disturbance-free resonators.

© 2019 IEEE