The diffraction property and its applications of holographic grating with double frequencies

The spatial diffraction properties of holographic grating with double frequencies (HGDF), are discussed in detail in this paper. It is pointed that the spatial diffraction properties of HGDF can be used to obtain two - beam interference field with equal intensities, which can be effectively used to produce holographic grating with high quality, or as a spatial virtual grating inducing Moire fringes to high sensitively measure micro displacement, rotate angle, deformation and 3-D outline of an object without contact. Several experiment results are also given.