Phase Compensation Retrieval Technology Of Holography Based On Complex Amplitude Extension Filtering

Digital holography has the advantages of non-contact,high-resolution,and digitization,which is suitable for dynamic real-time quantitative measurement of small samples.It has been widely used in the fields of micro and nano device detection,biomedical observation,and other fields.The digital holographic recording process introduces aberration information,resulting in the reconstruction results being affected by the aberration phase,which needs to be eliminated during the phase compensation process.Compared to traditional phase compensation technology,which difficult to take into account the compensation accuracy and speed of higherorder aberrations,low-pass filtering phase compensation technology can achieve simple and rapid compensation of all aberrations in a single hologram,but there are still shortcomings in the accuracy of phase retrieval of the sample to be measured and the degree of adaptation under different aberration systems.Therefore,how to achieve high-precision and self-adaptive digital holographic phase compensation retrieval has important research significance.The topic "Phase compensation retrieval technology of holography based on complex amplitude extension filtering" aims at the traditional low-pass filtering phase compensation technology,and based on the spatial and frequency domain characteristics of complex amplitude,studies the accurate and adaptive digital holography phase compensation retrieval technology.The specific research content is as follows:Firstly,the theory of low-frequency aberrations is studied.On the basis of analyzing the principle of low-pass filtering phase compensation technology,using the polynomial model of the aberration phase,the frequency characteristic of aberration complex amplitude is qualitative research,and the low-frequency distribution characteristic of aberration information in the spectrum of the hologram is verified,which provides a theoretical basis for further research on low-pass filtering phase compensation related technology.Then,in response to the problems of spectrum leakage and ringing effect in traditional low-pass filtering phase compensation technology,a low-pass filtering phase compensation retrieval technology based on complex amplitude expansion is proposed.Before filtering compensation,signal extension technology is introduced,which utilizes complex amplitude centrosymmetric extension to suppress boundary errors caused by holographic spectrum truncation,improving the compensation accuracy of aberration information and the retrieval accuracy of phase information of the tested sample.Finally,in response to the issue of traditional low-pass filtering phase compensation technology requiring manual parameter presetting in different systems,a phase compensation retrieval technology based on iterative extension filtering is proposed.On the basis of complex amplitude extension filtering technology,the phase map frequency calculation based on extreme points and the adaptive iterative filtering process are studied,which have better adaptability.And the aberration pre-compensation is used to further improve the accuracy of aberration compensation.The phase compensation retrieval of a single hologram is achieved.