Transmissive Digital Holographic Imaging Research Based On 46.9 Nm Laser

X-ray laser has the characteristics of short wavelength,large instantaneous power of pulse,high single photon energy,it plays an irreplaceable role in micro-fast process research fields.Among many X-ray implementation schemes,the capillary discharge scheme has the advantages of high energy conversion efficiency,simple structure and small volume,and can realize miniaturization of the device,and has been widely concerned by various countries.One application direction of X-ray lasers is holographic imaging.Since Gabor first proposed the concept of holography in 1948,the theoretical research and experimental research of holographic technology have developed rapidly.In theory,a variety of mature holographic rebuilding algorithms have emerged.In the experimental field,holographic imaging of visible laser and other long-wavelength lasers is more and more,and holographic imaging of 46.9 nm soft X-ray laser generated by capillary discharge pumped,is less.In this thesis,two-dimensional and three-dimensional transmissive digital holographic imaging is explored based on Gabor in-line holographic optical path using 46.9 nm soft X-ray laser pumped by capillary discharge.In the theoretical simulation,several common holographic reconstruction algorithms are compared,and the angular spectrum method is selected as the holographic reconstruction algorithm.In the two-dimensional transmissive digital holographic imaging simulation,the conditions in actual operation,such as imaging distance,hologram size,actual object size,recording medium pixel size,etc.)are simulated,and the influences of the results of holographic imaging recorded in different conditions are explored.In the three-dimensional transmissive digital holographic imaging simulation,the results of three-dimensional rebuilding of holographic imaging under different conditions is obtained,and the axial resolution results are explored.This thesis completed the digital full imaging experiment of 46.9 nm X-ray laser for the first time.Since the theoretical research of 46.9 nm laser is still immature and limited by experimental conditions,this thesis can only conduct corresponding theoretical experiments.In the experimental work,the difficulty of operating under vacuum and the selection and fixation of holographic imaging targets were overcome,and the experiments of two-dimensional transmissive digital holography and three-dimensional transmissive digital holography were completed.In the two-dimensional transmission digital holography imaging experiment,a nickel wire having a diameter of about 55 ?m and a silk having a diameter of about 10 ?m were holographically imaged,respectively,and clearly rebuilding by a reconstruction algorithm,and the horizontal resolution of about 10 ?m was obtained.Further,more complex objects such as atomic force microscope probes were imaged,The reconstructed images clearly shows the probe frame of about 6 ?m width,which proves that holographic imaging of more complex objects can be achieved under the experimental conditions and the horizontal resolution can be as low as 10 ?m or less.Finally,a method for obtaining higher resolution holograms is proposed.Its feasibility needs further exploration.In the three-dimensional transmissive digital holography imaging experiment,threedimensional holographic imaging of objects placed at different axial intervals,and the axial resolution is about 10 cm.Changing the size of the object within a certain range does not affect the axial resolution distance.