Investigation On The Imaging Of The Double Varied Line Space Plane Grating System

Bi-grating system combined by two plane gratings can bypass obstacles of objects into a clear image,which has a unique dispersion-combination of spectral imaging effect.Varied line space(VLS)plane grating has the unique advantages such as self focusing,and an object can be enlarged and reduced into a virtual image and real image with it.It is worthy to be studied that the imaging characteristics and laws of Bi-grating system combined by such gratings.Therefore,imaging of bi-grating system combined by two varied line space plane gratings is studied in this paper.We explore such bi-grating system imaging characteristics,understand the new rules,and provide a reference for bi-grating system applied in more and more fields.Firstly,the first-order Diffraction real image astigmation and magnification formed by a single plane two-dimensional curved VLS grating is studied.Homemade different spatial frequency distribution of two-dimensional curved VLS grating,and through experimental measure and analyze the grating parameters impact on the astigmatism and magnification.Finally,obtained the relationship between astigmation of two-dimensional curved VLS grating and the grating spatial frequency distribution coefficient in the expression to B and B',and the relationship between eliminating astigmatism incidence angle and the grating spatial frequency distribution coefficient in the expression to B?B'and C.Then,according to the study of astigmatism,two types of VLS bi-grating system imaging combined by fixed line space and varied line space plane grating in different turn are studied.The results indicate that under certain conditions,poly-chromatic light come from observation can be formed converging beam after the two types of systems,in which different wavelengths of light form a real image and enlarge virtual image respectively.And also come to the convergent beam conditions of these two systems and it's imaging features,that is to say,the relationship between the distance of two gratings and object distance and the the spatial frequency of the grating,as well as the relationship between distance?magnification and object distance,the wavelength of the incident.Based on this,a imaging system can enlarge the object is designed in this paper.