During an experimental trial, single-crystal sapphire fractured from excessive stress caused by laser heating. The experiment characterizes the optical distortions imaged through the non-uniformly heated window. Data collected in the experiment will validate optical, thermal, and structural models. The scattered light from a 633nm probe laser shows the outline of the broken window.
—Stuart A. Jackson, JHU/APL, Laurel, MD, USA
26 Jul 2021