Polarimetry using classical polarizing components and nanostructured beam splitting surfaces
Master thesis
Permanent lenke
http://hdl.handle.net/11250/2615591Utgivelsesdato
2018Metadata
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- Institutt for fysikk [2646]
Sammendrag
Two methods for generation and analysis of the polarization state of light are studiedin this thesis. The first method is based on a traditional bulk design consisting of twoactive components and 3 passive components in order to optimally generate 4 Stokesvectors, and analyse one complete Stokes vector, respectively. The innovative step reportedin this thesis is the combination of a 600-1100 nm 2-Ferroelectric Liquid Crystal(FLC) based system with a supercontinuum laser source tuned by an Acousto-OpticTunable Filter (AOTF). The system operates as a complete spectroscopic Mueller matrixEllipsometer for transmission measurements, using a single IngGaAs detector. Itshows highly promising results in the 700 to 930 nm range with a sub 2% Mueller matrixelement error. Equally good results in the 600 to 700 nm regime may also be possible.The behaviour of the AOTF and the FLCs were studied in terms of switching speedand stability. The source reached a stable state within 2 milliseconds after switching,and was stable with a variation <.2% in the short time regime. The FLCs revealed atendency to drift a short time after switching, and a stable state was not reached until0.2 seconds after switching was initiated.The second method for generation and analysis of the polarization state of light is theuse of passive beam splitting metasurfaces. I outline the design and production steps forbeam splitting surfaces, and report the preliminary results for a manufactured Au/oxide/Au thin film stack. Production involves the deposition of a multilayered film consistingof two layers of Au with an intermediate layer of SiO2, and thin adhesive layersof Ti. Characterisation of the films is performed using spectroscopic ellipsometry, ScanningElectron Microscopy (SEM), Atomic Force Microscopy (AFM), and 3D OpticalProfilometry. Important properties such as deposition rate and the resulting surfaceroughness have been determined, and satisfying optical models for each of the materialsand the multilayered film have been constructed. This forms a solid foundation for theproduction of films which can later be nanostructured into beam splitting surfaces.