以有限時域差分法分析三維金屬光子晶體及表面電漿現象

Abstract

在本篇論文中,我們將探討週期性金屬結構的現象及應用, 包含金屬光子晶體,金屬光柵。 在金屬光子晶體方面,利用鎢作為光子晶體材料,則有很大的潛力作為高效率的發光材料, 我們利用有限時域差分法求出木堆這種光子晶體結構的電磁波的穿透頻譜,進而驗證在紅外光波段這種結構有頻隙, 大部分的紅外光會被這種金屬反射,只有可見光能穿透, 而在頻隙邊界會有較大的吸收。 在金屬光柵方面,當電場垂直溝槽時會造成表面電漿效應而且在長波長部份會有極大的穿透率。 當電場平行溝槽則會有低頻頻隙,利用兩層光柵,設計成木堆結構,則可設計此種結構成色彩濾波器。

The electromagnetic phenomena and applications of periodic metallic structure are studied with the finite difference time domain method. Three dimensional tungsten woodpile structures has potential to luminesce efficiently. The transmission spectrums of the photonic crystals are obtained. The structures has band gap in the infrared region in which most electromagnetic wave in the infrared region is reflected and absorbed more in the band edge by tungsten. Only electromagnetic wave in visible region can pass through. Using silver as the gratings and electric field perpendicular to the grating grooves, there are surface plasmon phenomena and very high transmittance in long wavelength region. We will discuss the mechanism. When electric field is parallel to the grating grooves, there are low frequency band gaps. Using two gratings as woodpile structures, we can design the structures as color filter.