Elimination method of zero-order image and conjugate image of off-axis digital hologram

In order to improve the reconstructed image quality of off-axis digital hologram,an elimination method of zero-order image and conjugate image of off-axis digital hologram was presented.Based on reference light with a π phase shift and recording two holograms,Fourier transform was made for two subtracted holograms.Combined with spectral filtering method,the associated spatial frequencies was filtered out with rectangular window function.Then digital reconstruction was made.Experiments show that the method can eliminate the zero-order image and conjugate image even in the case that the zero-order image and others images overlap seriously,so the method can effectively improve the quality of reconstructed image in digital holography.