計畫名稱：積體化TE/TM極化分離器/合併器/轉換器之設計
執行起迄：2011/03/01~2011/10/31
總核定金額：595,000元
中文摘要：考量極化控制能力於高容量光通訊之光子積體線路晶粒的發展日益重要，本計劃旨在設計開發適用於半導體光放大器/雷射結構材料系統之TE/TM極化光 - 分離器/結合器/轉換器。 本研究以混成超模態波導(Hybrid Supermode Waveguide)為核心架構，利用混成超模態(S1&S2)僅受激於TM對稱模態(TMSym)及TE反對稱模態(TEAsym)之特殊性，結合一個以2x2 3dB多模干涉耦合器(MMI coupler)串接特殊設計90度相位調整器(Phase Shifter)所形成對光路徑敏感的模態轉換器，並利用一對漸變寬度波導及一個1x2 3dB多模干涉耦合器將上述連接與整併，形成一積體化於主動材料之1x2 TE/TM極化分離器/結合器/轉換器，最後利用光波導數值計算-「薄膜模態匹配波束傳播法」，設計實現出具TE/TM極化控制力三位一體能力之單一光積體線路。 根據設計模擬結果，本元件長度小於2.5mm，極化轉換率達99%，極化消光比大於50dB，且於中心波長1.55微米操作時，3dB波長不敏感頻寬達60nm。 由於此元件之設計以垂直脊狀波導為基礎，在研製上，不需特殊製程搭配，如階梯蝕刻、斜邊波導等，容易與現有的光子積體線路製程整合，具有發展的潛力。
英文摘要：Considering the ability of controlling polarization state has become the key issue in developing photonic integrated circuits (PICs) for high capacity optical transmission system, this proposal aims to develop a TE/TM polarization splitter/combiner/converter on SOA/Laser-based epi-structure. We use the hybrid supermode (HSM) waveguide as the core structure due to its special property, only can be excited by symmetric TM mode (TMSym) and asymmetric TE mode (TEAsym). A path sensitivity mode converter, made by a 2x2 3dB MMI cascaded a designed 90 degree phase shifter, is then introduced to this structure. Finally, last two parts (i.e. HSM and mode converter) are separately connected and combined by a pair of taper connecter and a 1x2 3dB MMI coupler to form an integrated active (i.e. based on active epi-structure such SOA/Laser) 1x2 TE/TM splitter/combiner/converter. In the end, we demonstrate a novel triple function TE/TM polarization controller by using the film-mode matching beam propagation method. In design, the device length is less than 2.5mm; meanwhile, it can achieve an extinction ratio (ER) > 50dB, a conversion ratio (CR) > 99% and a 60nm wide 3dB wavelength insensitivity when operating under wavelength=1.55 micron. In addition, the cross section of waveguide structure within our design only contain vertical shape without any stepper or angle ones, it will bring advantages in integrating polarization devices into PICs.