Dual-wavelength Digital Holographic Imaging Method And Application

Digital holographic technology combines mathematical technology,traditional optical holographic technology and photoelectric detection technology,and the threedimensional appearance of the target can be obtained by phase unwrapping the calculated complex amplitude distribution.Dual-wavelength digital holographic greatly reduces the difficulty of phase unwrapping.The main contents and results of this paper are as follows.Firstly,the theory of three-dimensional measurement of two-wavelength digital offaxis holography is introduced.Aiming at the digital off-axis holography,the recording of digital hologram,the calculation and reconstruction of the target image,the principle of obtaining the target three-dimensional information are analyzed in detail,and the numerical simulation is carried out.On the basis of this,the principle of dual-wavelength optical wrapping is introduced,and verified by numerical simulation.Then,aiming at the case where the phase depth to be measured exceeds the equivalent wavelength of the double wavelength,a solution for solving the numerical phase solution on the basis of the double-wavelength phase solution is proposed.In this paper,the principle of three kinds of algorithms for branch cutting,DCT least square method and minimum network flow method is described,and its performance is analyzed by numerical simulation.Combined with the comprehensive consideration of accuracy and timeliness,the network flow algorithm has the best effect.Finally,three-dimensional imaging detection based on dual-wavelength digital holographic technique is studied for long-range target imaging,and The influence of Gaussian noise on phase unpacking in optical imaging is analyzed.In order to solve the problem of small detection area and low resolution of digital holographic detection,a digital holographic synthetic aperture method with arbitrary displacement is proposed and verified by experiments.The results show that this method can significantly reduce the computational complexity of aperture synthesis at the expense of a certain resolution.Figure32;Table2;Reference 72...