| The basic methods of holographic interference[14] are as follows: single exposure (real-time), double exposure, continuous exposure(time-average), three beams single exposure, nonlinear recording holographic interference, holographic wave-front shearing interference, holographic Moire fringe technique and so on. There are many applications about holographic interference measurement. In this paper, the application of holographic single exposure is mainly studied. Firstly, the position of object before rotation (place sensitive plate on the rotation axis) is exposed. Then a piece of holographic grating is obtained. And the spatial period of this grating can be measured by reading microscope. Secondly, this grating is reduced in the same light path. Therefore, Moire fringe is formed by this grating and the position at the beginning and end of object rotating separately. It is collected by CCD camera and then processed by computer automatically, so minute angle can be figured out. Due to the amplifying effect of Moire fringe, measurement accuracy is high by adopting subdivision technique to Moire fringe. Experiments show that the resolution of angular measure can reach 0.01 degree. This method has many merits as follows: simple principle, real-time, accurate and so on. With this method, high-accuracy survey can be implemented by the minute angle (such as the gradient of machine tool carrier) and the displacement can be controlled effectively. Therefore, it is very important in practical engineering field. The main innovation of this paper is adopting holographic interference Moire fringe technique to measure minute angle. And it is simple, real-time and accurate. Further more, relative experimental installation is introduced and error is also analyzed in this paper.
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