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Identifier

000419060

Title

Developing and optimizing light sheet microscopy using opaque lenses and wave front shaping

Alternative Title

Ανάπτυξη και βελτίωση μικροσκοπίου φύλλου φωτός χρησιμοποιώντας αδιαφανείς φακούς και διαμόρφωση μετώπου κύματος

Author

Κεφαλογιάννη, Μαρία Γ.

Thesis advisor

Χαραλαμπίδης, Δημήτριος

Reviewer

Ζαχαράκης, Ιωάννης
Παπάζογλου, Δημήτρης

Abstract

For more than three centuries optical microscopy has been the basis of all biological studies and discoveries and the method of choice for high resolution imaging of biological tissue. However, microscopy and optical imaging in general are drastically limited by the inhomogeneities that light encounters as it propagates through tissue, manifested as random fluctuations of the refractive index. In this contest, adaptive optics and wave front shaping methods have been used to improve the capabilities of imaging systems to visualize features embedded in turbid and noisy environments. In a different approach we can use wave front shaping to manipulate the light propagation through specifically engineered anisotropic photonic structures, to improve the illumination and control of in and out of imaging systems. In such cases the use of active optical elements such as spatial light modulators (SLM) in combination with the scattering photonic structures creates new optical elements referred to as opaque lenses. In principle, the SLM configures the phase of the incident wave front through a feedback loop accounting for the measured output intensity, in order to compensate for the light path differences inside the medium. This process allows to take advantage of hidden coherent properties of the propagating wave and manipulate the illumination of the sample according to specific demands (e.g. focus or create a light sheet) In this thesis, we initially studied light scattering imposed by conventional diffusive samples such as ground glass diffusers, skin of flowers or white paper and optimized our wave front shaping technique to create a sharp focus. We then used specific photonic structures with various opacities, capable of creating speckle patterns that can produce focused light sheets. A thorough study was then performed to characterize the different light sheets in terms of width and spatial extension. The aim of this procedure was to define the specific parameters which will guide us to an appropriate light sheet that will potentially improve conventional Light Sheet Fluorescence Microscopy. In the future an appropriate opaque cylindrical lens could replace standard optics and enable LSFM to image deeper in biological tissue with high resolution.

Language

English

Subject

Anisotropic photonic glasses

Light scattering

Spatial light modulator

Ανισοτροπικά φωτονικά γυαλιά

Σκέδαση φωτός

Χωρικός διαμορφωτής φωτός

Issue date

2018-11-23

Collection