寬頻電漿子奈米天線陣列之設計與製作

Abstract

在本論文中，主要是在研究改變電漿子奈米天線中非偏振方向的橫向尺寸時，會使得電漿共振產生寬頻的響應，並分析當局域表面電漿發生時的遠場穿透頻譜以及近場局域電磁場的分佈。當增加橫向尺寸時，會使得頻譜上的共振波長位置產生明顯的藍移現象，且由於在奈米天線陣列之間發生磁場耦合的抵消效應，使得其電漿共振的頻寬會有上升的趨勢。此外，延伸奈米天線的非偏振方向尺寸時的各種響應與表現，也能藉由外加電磁場所驅動的等效電路模型來進行驗證與分析。其中成對式電漿子光柵的頻寬為成對式棒狀奈米天線2.04倍，以及能提供2.18倍的等效模態面積。

Plasmonic broadband resonance in gold paired-rods nanoantennas and paired-strips gratings is investigated when the nanostructure’s transverse (non-polarization) dimension is changed from paired-rods to paired-strips. Transmittance spectra and localized electromagnetic fields are analyzed when localized surface plasmon resonance occurs. Increasing the transverse dimension blue shifts the resonance wavelength and widens its bandwidth due to cancellation of the magnetic field between nanoantennas. A derived resistor-inductor-capacitor (RLC) equivalent circuit model verifies the nanostructures’ resonance when elongating the transverse dimensions. Paired-strips gratings have a bandwidth 2.04 times and mode area 2.18 times that of paired-rods nanoantennas.