| Summary: | 碩士 === 國立臺灣大學 === 物理學研究所 === 106 === With the incorporation of multiple elements or multiple resonances of nano-resonators into artifical plasmonic structures for optical components, these integrated-resonant units (IRUs), show a great ability for achieving controllable smooth and linear phase dispersion as well as amplitude manipulation over a continuous and broad bandwidth. Utilizing the property of IRUs design, we realize three achromatic deflectors showing constant steering angles of 9.5˚, 19˚, and 28˚ as the incident wavelength is varied from 400 to 667 nm (~50% bandwidth to the central wavelength). In, addition, three visible achromatic metalenses with various numerical aperture (NA) values and diameters are also experimentally demonstrated, displaying an unchanged focal length throughout almost the entire visible light wavelength range. The experimentally focusing efficiency of the achromatic metalens with diameter of 41.86μm achieves 26.31%, 19.71%, and 20.37%, respectively, at wavelengths of 420 nm, 550 nm, and 650 nm. Besides, a broadband versatile polarization generator is composed of multi-nanorod IRU design as building blocks numerically optimized to achieve above 50% conversion efficiency from visible to near-infrared (400 nm to 1400 nm). The versatile polarization convertor with high efficiency generates six common polarization states simultaneously upon one linear-polarized illumination. The maximal conversion efficiency for steered circular-polarized and linear-polarized output light beams reaches 80% and 40%, respectively. Our method with complete control of amplitude and phase response over continuously broad bandwidth provides an unprecedented platform in realizing multifunctional full-color meta-devices.
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