LIGHT MANIPULATION AND STRUCTURING VIA NANOFABRICATED FLAT METASURFACES

Abstract

THIS THESIS PROVIDES ORIGINAL INVESTIGATIONS AND DEMONSTRATIONS OF TWO RELATED TOPICS: SPIN-CONTROLLED LIGHT TRANSMISSION/MANIPULATION AND VORTEX LIGHT STRUCTURING VIA NANOFABRICATED DEVICES. THE MAIN CONTRIBUTIONS INCLUDE NOVEL METHODS OF PHOTON-SPIN'S DETECTION, OV GENERATION AND COMPLEX MANIPULATIONS AT MINIATURIZED SCALE. IN THIS REGARD, TWO TYPES OF FLAT STRUCTURES --- LOGARITHMIC SPIRAL (LS) AND BABINET-INVERTED METASURFACES --- ARE EMPLOYED TO SHAPE THE TRANSMITTED LIGHT IN MESO-FIELD. FIRST, SPIN-CONTROLLED BROADBAND LIGHT MANIPULATION IS DEMONSTRATED VIA AN LS-NANOSLIT. THE WORK, SCRIPTED IN CHAPTER 2, PRESENTS COMPREHENSIVE SIMULATION AND EXPERIMENTAL INVESTIGATIONS OF LIGHT DIFFRACTED THROUGH A LS-NANOSLIT, WHICH FORMS A TYPE OF SWITCHABLE AND FOCUS-TUNABLE STRUCTURE. OWING TO STRONG DEPENDENCE ON THE INCIDENT PHOTON-SPIN, THE PROPOSED LS-NANOSLIT CONVERGES INCOMING LIGHT OF OPPOSITE HANDEDNESS (TO THAT OF THE LS-NANOSLIT) INTO A CONFINED SUBWAVELENGTH SPOT, WHILE IT SHAPES