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Studying the electrophysical parameters of a holographic microscope
Abstract
In this work, the main parameters of a holographic microscope are studied with the aim of optimizing them. The optimum positions for the monochromatic electron-beam source with respect to the subject of research and for the screen detecting the interference pattern (the distance is 100 nm and 10 cm, respectively) are determined. The limiting thickness of the thin film of the subject of study (30 Å) at which the interference pattern can be observed is estimated. The main parameters of the coordinate-sensitive detector providing signal gain up to 105 at the output are calculated.
... In other words, with this method of image registration, the phase information is converted into intensity modulation, which Gabor called holography, i.e. complete record. For the implementation of Gabor holography using electrons, special electron microscopes have been developed -lensless low-energy electron microscopes LLEEM (point projection microscope PPM) [6][7][8]. For in-line holography, two main types can be distinguished, which in fact differ only in the type of wave incident on the object -spherical and plane. ...
We present the most common methods for the lensless visualization of individual molecules with an atomic resolution. The visualization is understood as a formation of an image by the lensless method and its subsequent numerical reconstruction. The basic principles of a formation of images of objects of study by the lensless method are presented. Discussions of holographic images of the objects of study, formed by the classical in-line method (in-line holography), with low-energy electrons are presented. Practical methods of modeling and numerical reconstruction of holographic images formed by the lensless method are presented.
... their information-based teaching level. In the lecture of educational technology expert, emerging educational technological means are introduced, such as introducing the application of 5G Cloud and AR technology in the creation of brand-new immersion teaching [16] and introducing 5G remote holographic teaching application [17]. The educational technology horizon of newly appointed teachers is broadened, and the development direction of technology and education fusion is indicated. ...
The improvement of strategies for information-based educational and teaching abilities of newly appointed teachers should be substantially investigated urgently based on the policy level of various countries or the reality of colleges and universities. However, from the perspective of the Technological Pedagogical Content Knowledge（TPACK）hierarchy, there are only a few studies on the strategies to improve the information-based educational and teaching abilities of newly appointed teachers. Therefore, this study analyzed the relationships between the three cores and four composite elements, designed the ability improvement strategy corresponding to each element, designed a hierarchical improving strategy which corresponds to 20 training contents, and used quasi-experimental research methods to apply the strategy to the 2019 newly recruited teacher training system of Guangdong University of Finance and Economics. Through the implementation of the training strategy for one semester and effect evaluation, combined with the comparative analysis of the training evaluation data of newly appointed teachers who did not implement this strategy in 2018, it shows that the implementation of the strategy can significantly improve the information-based educational and teaching ability of newly appointed teachers, with good results.
The parameters of a kendroscope associated with the necessary position of the electron source and the object of research are optimized. The selection of thin layers of some metals suitable for visual observation of their structure and initial film growth is carried out.
Systems of monolayer films of graphene, porthyrin, copper and zinc phthalocyanine are investigated. For all systems equilibrium geometries are found, all structures are flat, except for a chlorine-replaced copper phthalocyanine. DFT modeling of the structure of thin films is performed as substantially promotion in interpretation of the results received by means of a holographic microscope.
A holographic microscope is intended for investigation and visual observation of nanoobjects that are thin metal films or macromolecules. A module providing for the experimental research of such objects has been designed and built. The optimal thickness of the metal films has been estimated. Software for processing the interference patterns with the aim of obtaining a holographic image of nanoobjects has been developed.