The Research Of Bi-grating Diffraction Imaging

Grating has the nature of dispersion,can be used as a kind of splitting element,mainly used to obtain spectral,widely used in information storage,high power laser pulse compression,optical modulation and many other fields.the grating develop from simple to complex,from single score to diversity grating process such as holographic grating.According to the reversibility of optical path,to analyze that grating has the function of each beam arranged on the spectral together –spectral combination character of grating.Combining light splitting and spectral combination character of grating to design bi-grating diffraction imaging experiment,which helps people know grating from different views.imaging systems has played a role in the transfer of images.The imaging equation of the bi-grating is calculated by the theory and the experiment is carried out.The image into the bi-grating diffraction as with the original after the first zero order diffraction grating exists transverse and longitudinal offset,so to design experiments to discuss the influence factors of the offset of the transverse and longitudinal.Through the experimental study of grating astigmatism confirms the necessity of the bi-grating diffraction imaging needs to satisfy the condition of minimum deviation angle.From the point of bi-grating diffraction imaging,the ordinary transmission hologram with white light source is proposed.This method gets rid of the dependence on laser when hologram displays,and display the vivid three-dimensional image object,widen the application of holographic technology in biology,medicine,agriculture and other areas.Bi-grating imaging and hologram with white light source are two different types of imaging.One is the real-time virtual image,another is the virtual image that is recorded in the hologram.But the two ways has the same essence,bi-grating diffraction imaging is the theory base of hologram whit white light source.Once the grating combination satisfy the bi-grating imaging equation,bi-grating diffraction phenomenon will occur,so the hologram with white light source has advantages of the frequency of the grating without special requirements.