Imaging Characteristics Of Incoherent Digital Holography And Application In Spectrum And Polarization Detection

The incoherent correlation digital holography based on Spatial Light Modulator(SLM)has broken the limitations of the conventional holography: namely the demands for highly coherent laser,complex optical system,lots of time and fabricating cost,which has many advantages of simple recording system structure,flexible reconstruction method,and matching with any standard optical system.This dissertation focuses on the incoherent digital holography system,where SLM and a charge-coupled device(CCD)are considered as the core components,analyzes the point spread function and explores the imaging characteristics combining with experiments.In addition,the incoherent digital holography is combined with microscopic imaging,hyperspectral imaging,and polarization imaging techniques,which not only offers a fast recording and digital reconstruction,but also expands the dimension of information by obtaining the edge enhancement effect of micron scale biological samples,extracting the spectral curve of arbitrary pixels and detecting the polarization state of incident light.There are potential application properties in the fields of biology,military,and agriculture.Mentioned above can be summarized in the following four aspects:(1)The basic imaging principle of SLM-based incoherent digital holographic system is analyzed,and the parameters such as the point spread function and the lateral magnification are deduced by using the Fresnel diffraction integral formula.To study the properties of this imaging system,the USAF1951 standard resolution target and the physical dice are used as the measured object,which gives the resolution and three-dimensional imaging effects of the system.(2)Combining incoherent correlation digital holography with microscope technology,the imaging result of the resolution target is acquired,and magnification of the system is calibrated.The calibrated system was used to perform magnification microscopy imaging on biological samples.In addition,the imaging characteristics of the system when loading the spiral phase mask on the SLM are studied,and themathematical formula of the Point Spread Function is given.Compared with holographic microscopy imaging,the edge extraction and enhancement of object was achieved,without loss of resolution.(3)Through the introduction of liquid crystal tunable filte,SLM-based the incoherent digital holography hyperspectral imaging system is built to record the spectral holograms without scanning,the 3D reconstruction image of the object and the spectral information of an arbitrary pixel can be obtained after numerical reconstruction and image fusion.(4)SLM-based the incoherent digital holography polarization imaging is built.Using the Stokes vector method to describe the polarization state of the light wave,the holograms at 0°,45°,90°,and 135° are recorded by adding a polarizer to the optical path.After the numerical reconstruction and processing,the polarization degree image of the object is obtained.