結合光柵、波導、與金屬奈米二聚物結構之晶片化表面電漿元件於生物感測應用之研究

Abstract

近年來，表面電漿(Plasmonics) 成為奈米光子學領域中一項非常重要的研究，主因製程技術的進步實現了金屬奈米粒子之侷域表面電漿共振現象。其模態對於介質環境的高靈敏度，以及具光學檢測的即時性，已被視為感測應用上一門重要的技術。然而一般用以激發表面電漿共振的全反射稜鏡架構，除了其價格昂貴以及對系統的穩定度要求高，因其體積龐大不利於感測系統的晶片化，限制了許多實際應用的可能性。 為克服上述問題，在本計畫中我們提出對微小粒子具超高感測靈敏度的金屬奈米二聚物結構，並整合光柵與波導，做為表面電漿共振之激發與感測訊號傳遞的架構，實現晶片化之感測系統。計畫第一年中，我們首先著重於優化金屬奈米二聚物結構的感測能力，並探討波導設計如何有效激發表面電漿共振。同時我們也會針對光纖波導間的垂直耦合光柵做一系列結構的分析，並依此設計高效率耦合光柵。而計畫的第二年，我們將以光柵、波導與金屬奈米二聚物結構等三種元件整合於同一晶片上為目標，並研究此積體化系統晶片的生物感測能力。藉由結構的設計、優化與整合，我們將實現晶片化之高效能表面電漿奈米生物感測器，可望增進未來在醫學診斷、疾病監控與藥物研發的發展性。

In recent years, plasmonics has become a very critical research in nanophotonics because of the advance in fabrication, which realizes localized surface plasmon resonance (LSPR) on metal nanoparticles. The high sensitivity to surrounding media and immediate detection make LSPR regarded as one of the most important technique in sensing. However, the commonly used prism configuration for exciting LSPR is always expansive and requires very high stability. Besides, it is too massive to be integrated into a chip, which leads to limitation in many practical applications. In order to overcome the mentioned problems, we propose a metallic nanodimer with ultra-high sensitivity to tiny particles. To realize lab-on-a-chip sensing system, grating and waveguide are incorporated with the nanodimer for LSPR excitation and signal transmission. In the first year of this project, we will focus on optimizing the metallic nanodimers for high sensitivity, and investigate how to excite LSPR efficiently by waveguide design. At the same time we will do a series of detailed analysis on vertical fiber-waveguide grating coupler to achieve high coupling efficiency. In the second year of this project, we will combine grating, waveguide, and metallic nanodimer to study biosensing characteristics of such integrated chip system. Via the structure design, optimization, and integration, we will realize integrated plasmonic chip system to serve as a highly sensitive optical nano-biosensor for the development of medical diagnosis, monitoring of diseases and drug discovery in the future.