“…The exact mechanism leading to the creation of these nanofeatures [2,[10][11][12][13] is to date not established. Nonetheless, this type of modification has been used in various photonics applications, such as polarization converters [14] or optical memory devices [15], but also for controlling the stress state in materials [16,17], inducing controlled displacements [18][19][20], or for tuning properties, such as the coefficient of thermal expansion [21]. To date, these changes of thermomechanical behavior cannot be fully understood, predicted, and controlled without a deeper * pieter.vlugter@epfl.ch understanding of the mechanical properties of the nanogratings.…”