Large-Aperture, Long-Path Interferometer For Measuring Transient Thermal Fields

This paper discusses the principles of a large-aperture, long-path interferometer consisting of two mirrors. Its merits include a characteristic of differential interference, a relatively relaxed requirement on optical material, high resistance to disturbance and vibration, and high accuracy of fringe location. It can operate in such adverse circumstances as an explosion field, a rocket exhaust plume field, and other transient processes. Interferograms of various flames, of the near-field structure of a rocket exhaust plume, and of a shock wave field are obtained with this interferometer.