Core optics components for high precision measurements are made of stable materials, having small optical and mechanical dissipation. The natural choice in many cases is glass, in particular fused silica. Glass is a solid amorphous state of material
that couldnt become a crystal due to high viscosity. However thermodynamically or externally activated stimulated local processes of spontaneous crystallization (known as devitrification) are still possible. Being random, these processes can produce an additional noise, and influence the performance of such experiments as laser gravitational wave detection.
