Interferometric measurements of high temperature objects by electronic speckle pattern interferometry.

Electronic speckle pattern interferometry with a cw laser has been used to study objects at very high temperatures. Interference patterns were observable to 1700°C, while high contrast interference fringes could be recorded up to 1550°C. These temperature limits were mainly set by the onset of surface reactions and melting of the objects. Examples on how the technique can be used to study deformations, oxidation shell growth, and melting zones are presented.