抗諧振反射光波導之多模干涉式分光元件之設計、研製與特性量測

Abstract

本論文研究抗諧振反射光波導(ARROW)之多模干涉式分光(MMI)元件，包括其設計、元件製作與特性量測。由於抗諧振反射光波導具有較大的入射導光區，因此可以有效地和單模光纖耦合；再者多模干涉式分光元件具有簡單的結構與均勻等分能量的特性，因此兩者結合可得更好之效能。首先利用轉移矩陣法(TMM)和等效折射係數法(EIM)來分析及模擬抗諧振反射光波導之結構，接著應用波束傳輸法(BPM)來設計多模干涉式分光(MMI)元件。藉由上述之分析方法，我們設計1×2、1×4兩種抗諧振反射光波導之多模干涉式分光元件，且實作其元件並加以量測特性。量測結果如下 : 1×2多模干涉式分光元件TE模態的損耗為1.61~2.22 dB，TM模態的損耗為1.67~1.87 dB，分光波道間之不均勻度差TE模態為0.07~0.29 dB，TM模態為0.13~0.26 dB；1×4多模干涉式分光元件TE模態的損耗為 2.29~2.76 dB，TM模態的損耗為 2.01~2.44 dB，分光波道間之不均勻度差TE模態為0.74~1.15 dB，TM模態為0.76~0.97 dB。ARROW結構之TE模態的傳輸損耗為2.24~2.47 dB/cm，TM模態的傳輸損耗為5.73~6.06 dB/cm。最後探討量測誤差及建議改善方法。由製作之MMI分光元件顯示其確實具有均勻分光之特性。

In this thesis, anti-resonant reflective optical waveguides (ARROW) based multi-mode interference (MMI) power splitters are discussed, including design, device fabrication, and characterization. With thicker guiding region, ARROW could be coupled with single-mode fiber more efficiently. Furthermore, MMI devices possess the features of compact structure and output balancing. Better performance is realized by designing MMI power splitters with ARROW structure in the vertical direction. We begin with analyzing and simulating ARROW structure with the transfer matrix method (TMM) and the effective index method (EIM). Subsequently, the beam propagation method (BPM) is utilized to design MMI power splitters. By above analytical methods, we designed 1×2 and 1×4 ARROW based MMI power splitters. In addition, we fabricated these devices and measured the characteristics. The measurement results as following: The losses of 1×2 MMI power splitter are 1.61~2.22 dB for TE mode, 1.67~1.87 dB for TM mode. The imbalances of 1×2 MMI power splitter are 0.07~0.29 dB for TE mode, 0.13~0.26 dB for TM mode. The losses of 1×4 MMI power splitter are 2.29~2.76 dB for TE mode, 2.01~2.44 dB for TM mode. The imbalances of 1×4 MMI power splitter are 0.74~1.15 dB for TE mode, 0.76~0.97 dB for TM mode. The propagation losses of TE and TM modes are 2.24~2.47 dB/cm and 5.73~6.06 dB/cm. Experimental results are discussed and some suggestions are given. Measured results show that our MMI power splitters can provide the characteristic of power balance.