The Study Of Filtering Imaging Based On Bi-Grating Dispersion Combination Spectral Imaging Effects

Gratings are widely used in all aspects of scientific research and social production, it is not only well known as spectral dispersion element, the grating can also be used as the imaging element. Bi-grating dispersion combination spectral imaging effect is a clever use of the spectral dispersion of the grating, the combined effect of the convergence of spectral imaging,which allows multi-wavelength light complete achromatic imaging through the dispersion action of the first grating and the combined effect of the second grating spectral effect, and to achieve imaging bypassing the object. Due to its unique dispersion and convergence spectral imaging process, the possibility of the filtering imaging is provided in a filtering process can be carried out in the imaging process. This paper is filtered imaging study based on the bi-grating dispersion-combination spectral imaging effect. This paper is the application of research of bi-grating dispersion combination spectral imaging effects by using of theory, experiment and simulation methods. First, according to the Fresnel diffraction theory, this paper get the distribution of the grating diffraction field with rear diaphragm, and the relationship between the diffraction optical field distribution and the position of the grating, or the position size of the light source. Secondly, by using of experiments and simulation methods, this paper conducted a study of filter condition based on bi-grating dispersion combination spectral imaging effects.This paper analyzed the different parameters matching bi-grating system, the aberration of the diffraction image when the bi-grating have angle, the curve between imaging position and the angle of bi-grating, and got the conditions of highest quality imaging.This paper made application design research, designed the filter based on bi-grating dispersion-combination spectral imaging effects, and produced a prototype. Also, we did experiments to test its filtering effect. The results shows, the filter can filter out the specific wavelength and clear imaging, under proper placement.