Technique of step acousto-optical deflection and its application in high speed interferometric photography

This paper presents a technique of step acousto-optical deflection and its application in high speed interferometric photography. When a light beam earring interferogram passes through an acousto-optical deflector, it is deflected into 10 speckles (φ6mm - φ8mm in diameter) by time-sequence and recorded on a fixed film under the action of step pulsed ultrasonic wave. The exposure time of every speckle is 10μs - 3μs, and the interval between two speckles is 10μs. The multi-frames interferograms of transient combustion field produced by laser to ignite initiating agent are recorded by using this method with combination of laser interferometer, and the temperature distribution with time change is calculated quantitatively.