Transmission Mode K-domain Transform Based Imaging Method

Three-dimensional imaging technology is widely used in contemporary society,especially in the fields of information and biological sciences.The three-dimensional information of an object is of great significance for people to correctly understand and explore its structure and three-dimensional appearance.With the rapid development of science and technology in recent years,people's demand for the ability to extract three-dimensional information of objects is also increasing.Modern three-dimensional imaging methods is gradually developing towards highresolution,recording color images,and dynamic imaging,which constantly poses new challenges to traditional three-dimensional imaging technology.In recent years,people have developed many brand-new three-dimensional imaging technologies,including holography,laser scanning confocal microscope,optical coherence tomography,etc.Among them,digital holography technology is widely used in various threedimensional imaging fields due to its own unique imaging characteristics and advantages.Because the digital holography technology can reconstruct the complex amplitude of the light field on the recording plane and propagate to the object plane through numerical diffraction,thereby obtaining the light field distribution of the object.However,for samples with high transmittance and weak scattering,traditional digital holography cannot achieve tomographic imaging of objects at different depths.In recent years,a variety of newly digital holographic3 D imaging technologies have been developed,but they all have more or less disadvantages,such as complex structures and slow imaging speed.Therefore,in order to overcome the abovementioned disadvantages in the current digital holographic 3D imaging technology,this paper designs and proposes a transmission mode K-domain transformation 3D imaging method that is completely different from the traditional 3D imaging technology.It only requires singlewavelength illumination and one-dimensional directional movement.Scanning can realize tomographic imaging of three-dimensional objects,which greatly simplifies the structure of the optical system and significantly accelerates the imaging speed.The transmission mode K-domain transformation three-dimensional imaging technology proposed in this paper uses light-sheet illumination light to illuminate objects,introduces reference light to interfere and records off-axis holograms with the transmitted light of the object.The spatial spectrum of transmitted light can be reconstructed by using traditional digital holography.After that,the zero-order diffracted light component in the spectrum is filtered out by the high-pass filtering method,and then the spatial spectrum is converted to another plane through K-domain transformation,and the inverse Fourier transform is performed on it to obtain the spatial distribution on that plane.The tomographic image of the entire object can be reconstructed by scanning the object in one dimension along the horizontal direction and combining them.According to the transmission mode K-domain transformation three-dimensional imaging method proposed in this paper,its basic principles and characteristics are analyzed.Numerical simulations and actual experiments are implemented to verify the feasibility of the method.The high-pass filtering method introduced therein is analyzed and the characteristics are explained.The horizontal,vertical,and axial resolutions of the imaging system are 31.3um,44.2um,and1 mm,respectively.From the experimental data,the resolution capability of the built-up transmission K-domain transformation three-dimensional imaging system is quantitatively measured.Because this method can use transmitted light for three-dimensional tomography,it can be extended to X-ray imaging and other short-wavelength measurements,and due to its onedimensional scanning mode,it can achieve fast three-dimensional imaging,which can be used to study the interior structure of the sample.It has potential application value in studying the three-dimensional structure information of samples and biological dynamic observation and imaging.