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Preparation and characterization of optical metasurfaces
Weiss, Vlastimil ; Čižmár, Tomáš (referee) ; Dvořák, Petr (advisor)
This thesis presents a comprehensive study on the preparation and characterization of dielectric optical metasurfaces. Optical metasurfaces, which are artificially structured surfaces, enable precise manipulation of electromagnetic waves at a subwavelength scale, surpassing conventional optics in terms of spatial resolution and the complexity of optical transformations. The work is conducted at the Institute of Physical Engineering, Brno University of Technology in colaboration with CEITEC, and involves the use of advanced techniques such as ion beam etching through masks created via electron beam lithography (EBL) and the deposition of optically active materials into EBL matrices. The primary objectives include a thorough literature review, the fabrication of dielectric metasurfaces based on phase control mechanisms, and the detailed morphological and optical characterization of the produced structures. The research employs digital holographic microscopy and confocal optical spectroscopy for optical characterization, as well as numerical and semi-analytical simulations. The results contribute to the ongoing development of high-efficiency optical components and highlight the potential applications of biophotonic devices in the field of nano-optics.
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Holography in the short-wave infrared range
Schlor, Michal ; Baránek, Michal (referee) ; Bouchal, Petr (advisor)
This master's thesis focuses on digital holography in the near-infrared region. Digital holography is a method that allows for the reconstruction of phase changes and is therefore suitable for studying optical metasurfaces and their properties beyond the capabilities of traditional intensity measurements. The initial research part of the thesis discusses the theory of optical metasurfaces and the principles of digital holography. The acquired knowledge is utilized in the subsequent section of the thesis, which deals with the design of a holographic module that, when connected to a suitable imaging system, enables the implementation of digital holographic microscopy methods. The holographic module is based on a geometric-phase metasurface made of silicon, which allows for operation at a central wavelength of 1550\,nm. The thesis provides a theoretical design of the metasurface and the entire holographic module. The obtained parameters are verified through numerical simulations of holographic imaging. The practical part describes the experimental procedure for testing samples of the geometric-phase metasurface and demonstrates its integration into the assembled holographic module. In the conclusion of the thesis, the holographic module is connected to a microscope and tested under holographic microscopy conditions. The results of the master's thesis can be applicable for investigating phase changes induced by tunable metasurfaces made of vanadium oxide.
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Holography in the short-wave infrared range
Schlor, Michal ; Baránek, Michal (referee) ; Bouchal, Petr (advisor)
This master's thesis focuses on digital holography in the near-infrared region. Digital holography is a method that allows for the reconstruction of phase changes and is therefore suitable for studying optical metasurfaces and their properties beyond the capabilities of traditional intensity measurements. The initial research part of the thesis discusses the theory of optical metasurfaces and the principles of digital holography. The acquired knowledge is utilized in the subsequent section of the thesis, which deals with the design of a holographic module that, when connected to a suitable imaging system, enables the implementation of digital holographic microscopy methods. The holographic module is based on a geometric-phase metasurface made of silicon, which allows for operation at a central wavelength of 1550\,nm. The thesis provides a theoretical design of the metasurface and the entire holographic module. The obtained parameters are verified through numerical simulations of holographic imaging. The practical part describes the experimental procedure for testing samples of the geometric-phase metasurface and demonstrates its integration into the assembled holographic module. In the conclusion of the thesis, the holographic module is connected to a microscope and tested under holographic microscopy conditions. The results of the master's thesis can be applicable for investigating phase changes induced by tunable metasurfaces made of vanadium oxide.
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