雙抗諧振反射光波導分光元件之設計、研製與特性量測

Abstract

本論文研究雙抗諧振反射光波導(dual ARROW)分光元件，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厚的入射導光區，因此可以有效地和單模光纖耦合；再者雙抗諧振反射光波導具有耦合長度與波導間距呈現週期性的特性，因此可依不同需求，設計出具有不同波導間距的元件。在此研究中，首先利用轉移矩陣法(TMM)和等效折射係數法(EIM)來分析及設計抗諧振反射光波導之結構，接著應用波束傳輸法(BPM)來模擬雙抗諧振反射光波導分光元件。藉由上述之分析方法及模擬結果，我們設計波導間距為3.2微米以及13.8微米兩種雙抗諧振反射光波導之分光元件，進而實作其元件並加以量測特性。量測結果如下 : 3.2微米雙抗諧振反射光波導分光元件分光波道間之不均勻度差平均值及標準差對TE模態為1.201 dB及0.321 dB，TM模態為1.369 dB及0.244 dB；13.8微米雙抗諧振反射光波導分光元件分光波道間之不均勻度差平均值及標準差對TE模態為1.262 dB及0.273 dB，TM模態為1.627 dB及0.229 dB。Ridge ARROW結構之TE模態的傳輸損耗為0.928~1.264 dB/cm，TM模態的傳輸損耗為3.899~4.131 dB/cm。最後探討量測誤差及建議改善方法。由製作之雙抗諧振反射光波導分光元件顯示其確實具有分光的能力。

In this thesis, dual ARROW power splitters are investigated, including device design, fabrication, and characterization. With thicker guiding region, ARROW could be coupled with single-mode fiber more efficiently. Furthermore, dual ARROW waveguides possess the significant feature that the relation between the coupling length and the separation width is periodic. Better performance is realized by designing dual ARROW power splitters with ARROW structure in the vertical direction. We begin with analyzing and designing ARROW structure with the transfer matrix method (TMM) and the effective index method (EIM). Then, the beam propagation method (BPM) is utilized to simulate dual ARROW power splitters. With above analytical methods and simulation results, we designed dual ARROW power splitters with two different separation widths which are 3.2 μm and 13.8μm. In addition, we fabricated these devices and measured the characteristics. The measurement results as follows: The average value of the imbalance and the standard deviation of the power splitter whose separation width is 3.2 μm are 1.201 dB and 0.321 dB for TE mode, 1.369 dB and 0.244 dB for TM mode. The average value of the imbalance and the standard deviation of the power splitter with the separation width of 13.8 μm are 1.262 dB and 0.273 dB for TE mode, 1.627 dB and 0.229 dB for TM mode. The propagation losses of the ridge waveguide for TE and TM modes are 0.928~1.264 dB/cm and 3.899~4.131 dB/cm. Experimental results are discussed and some suggestions are given. Measured results show that our dual ARROW power splitters have the ability to provide the characteristic of power balance.