抗諧振反射光波導結構之多模干涉式分光元件之研究

Abstract

本研究在設計抗諧振反射光波導結構之多模干涉式分光元件。利用自身成像原理來運作的多模干涉式元件，具有簡單結構和能均勻等分輸出能量的特性，故極適合用來作為分光件。而抗諧振反射光波導元件則具有較大的導光區，所以能夠有效地和單模光纖匹配。理論上，先以特徵轉換矩陣法和有效折射係數法分析此元件中的模態，然後使用模態傳輸分析法來模擬在多模光波導內各模態傳播的情況，最後再應用光束傳輸法來驗證元件之特性。於本研究，設計了1╳2與1╳4分光元件。1╳2分光元件的損耗為0.2 dB; 而1╳4分光元件的損耗為0.4 dB, 分光波道間之不均勻度差為0.38 dB。對維持能量損耗小於0.7 dB及不均勻度小於0.5 dB元件特性之各元件參數容忍度也加以探討。

in the studies, we investigate the multimode interference power dividers based on the antiresonant reflecting optical waveguide structure. MMI devices, based on self-imaging effect, are compact and preserve the balanced output characteristics. The ARROW structure provides a single-mode propagation with a large core size and efficient coupling to single-mode fibers. The characteristic matrix method and effective index method are employed in modal analysis. Mode propagation analysis is used to simulate the mode propagating in the multimode waveguide. Then, use the beam propagation method to verify the results. In the studies, 1x2 and 1x4 power dividers have been designed. The excess loss for 1x2 power divider is 0.2 dB, and the excess loss for 1x4 power divider is 0.4 dB with 0.38 dB imbalance. The tolerances of device parameters have also been investigated.