Vlugter, PieterBlock, EricaBellouard, Yves2019-06-182019-06-182019-06-182019-05-1010.1103/PhysRevMaterials.3.053802https://infoscience.epfl.ch/handle/20.500.14299/156944WOS:000467746600003Femtosecond laser exposure of fused silica in the nonablative regime can lead to various localized bulk modifications of the material structure. In this paper, we show that these laser-induced modifications can be used to tune silica thermal expansion properties permanently. In particular, we demonstrate that a given exposer regime leads to lower thermal expansion than the bulk, while other exposure conditions yield the opposite results. This remarkable property enables the possibility to engineer a given thermal expansion behavior by selectively exposing a material volume to a femtosecond laser beam. This finding opens up opportunities for a variety of integrated precision instruments and optical devices for which inertness to thermal fluctuations is essential.Materials Science, MultidisciplinaryMaterials Scienceoptical wave-guidesmechanical-propertieselastic-moduliwrittenintegrationglassmicromechanicsbirefringencedependencetext::journal::journal article::research article