Fast Phase Imaging Method Without Unwrapping And Its Experimental Research

Most biological cells are colorless and transparent,and traditional medical observation methods have certain damage to the cells.The phase microscopy technique takes the physical and optical features of cells as a starting point,and realizes non-invasive and non-damage detection,which is a powerful method to study the morphological and dynamic features of cells.Phase microscopy also plays an increasingly important role in other optical measurements and imaging.The quality and efficiency of phase imaging directly affect the observation results of the object to be measured,and these often depend on the imaging method and phase recovery method.Usually in single-wavelength phase microscopy imaging,the discontinuous phase obtained first requires complex phase unwrapping operations to obtain the true phase.This process is generally time-consuming and difficult to apply to complex structures.The effect will have a great impact to the image quality.Therefore,the research on phase imaging methods without unwrapping is of great significance.This paper focuses on fast phase imaging method without unwrapping and its experiments.The main content is as follows.(1)Considering the typical dual-wavelength imaging technology requires multiple frames of images and relatively complicated experimental operations,and to improve the efficiency of imaging,two dual-wavelength three-step phase-shifting imaging methods without unwrapping are proposed to improve the imaging efficiency: derivative method in off-axis interferometry and radial Hilbert transform method in any mode.Both methods only need three dual-wavelength interferograms to obtain the phase,and both have been verified by simulation.Meanwhile,a dual-wavelength experimental optical path was established,and the Hilbert method was experimentally studied and verified.The results show the feasibility of the two methods.(2)To further improve the efficiency of dual-wavelength imaging and avoid the influence of parameters and other changes during phase imaging,a fast Hilbert method for phase recovery is proposed.This method requires only a dual-wavelength interferogram,and the phase information of synthetic wavelength can be obtained through multiple Hilbert transforms.This method was compared with other typical methods.The results show that the method improves the measurement efficiency under high precision.(3)For heterogeneous nucleated cells with complex internal structure and difficult for phases unwrapping,a method for quickly identifying cell substructures by wrapped phases was proposed.This method successfully extracted some substructure information of nucleated cells,and performed feature analysis and preliminary identification of these models.Based on the physical mechanism of phase microscopic imaging,and using dual-wavelength technology and image processing technology,several fast phase imaging methods without unwrapping and substructures recognition method were proposed by mathematical analysis and numerical simulations.Some methods,which are supported by experiments,realized efficient phase microscopic imaging.A new breakthrough direction is pointed out for the development of biological cell microscopic imaging technology.