Research On Multi-Order Diffraction Suppression Method Of Grating In DCPSI

Polarization imaging technology is widely used in military equipment,machine vision,biomedicine,atmospheric observation and remote sensing,target recognition and many other fields.Therefore,it is of great practical significance to improve the polarization imaging technology,especially to improve the structure used in the polarization imaging technology or the methods in it.This thesis studies the structure and basic principles of snapshot white light polarization imaging interferometer with dispersion compensation(DCPSI).It mainly analyzes how the blazed grating in DCPSI can solve the problem that the polarized Sagnac interferometer can only be applied to narrow spectrum.But DCPSI also brings a new problem while solving the problem,that is,the blazed grating will generate multi-order diffraction.Based on the study of the grating structure in DCPSI,the diffraction efficiency of each diffraction order of the grating,and the effect of grating multi-order diffraction on the imaging quality,it was found that multi-order diffraction would cause the ratio of the useful interference fringe signal to the background signal to decrease generated by DCPSI system,which ultimately affects the imaging quality.In order to solve the effect of multi-level diffraction on imaging quality,two suppression methods are proposed,The first is to propose a birefringent prism suppression method based on the principle of birefringent prisms,designing a birefringent prism structure for DCPSI system,the research results show that the experimental structure of the designed birefringent prism can well isolate the multi-level diffraction generated by the grating and improve the useful interference fringe signal to the background signal;The second is to propose a parallel plate suppression method based on the principle of parallel plates,designing a parallel plate structure for DCPSI system,The research results also show that the designed parallel plate experimental structure can also isolate the multi-level diffraction generated by the grating and improve the useful interference fringe signal to the background signal.Both methods can effectively isolate the multi-order diffraction generated by the grating in the DCPSI system to achieve the purpose of improving the imaging quality...