Study On Characters Of Nonlinear Exposure In In-line Holography For Particle Field

In this dissertation, the background and significance of characters of nonlinear exposure in the in-line holography for particle field was stated. The problem was theoretically and experimentally studied.(1) First the formula of in-line holography under the nonlinear exposure were got by using the theory of in-line particle holography and nonlinear exposure. Then through simplifying model and using the threshold value function to substitute the polynomial, the reconstruction image was analyzed under the nonlinear exposure. The reconstruction image appears the edge enhancement. Also the intensity of the reconstruction image was studied in the angle of the influenced by the diffraction efficiency. The diffraction efficiency of the low frequency is lower than that of the high frequency.(2) The contrast in the linear exposure is better than in the nonlinear exposure by using the Kozma model to analyze. The model of the reconstruction image in the condition of nonlinear exposure was constructed. The reconstruction images of the different shape particles were stimulated in the nonlinear exposure. The edge enhancement appears, especially, in the utmost condition i.e. the binarization of receding light intensity.(3) The experiments were designed. The results of the experiments and the formula derivation and the numerical stimulation were in agreement.(4) The edge enhancement of reconstruction image emergences in the dense particles field in the linear exposure. The phenomenon was analyzed theoretically. And the more dense particle, the easier edge enhancement comes out in the center particles. Through the research of nonlinear phenomenon in the dense particles field, the understand of the study on characters of nonlinear exposure in in-line holography for particle field was all-round.