近年來由矽晶電路製造技術不斷的進步，矽晶光電技術也受到極大的重視，世界各國無不戮力於此領域 的研究，並想把矽晶積體電路成功的經驗複製到積體光電路。其中有一項很重要的應用就是光子-微波系 統。在傳統的微波、毫米波系統使用光子技術可以有機會大幅提升其性能，然而由於多了光-電/電- 光的轉換過程，使得整個系統變得更為複雜，體積更大。此計畫的精神就是想利用矽晶光電技術，將 光子-微波系統的體積微縮，而且並不犧牲其性能。 一個具有高速、高線性度、低驅動電壓的光電調製器在光子-微波系統中扮演了極重要的角色。在 矽晶光電的調製器中，最常使用的調變機制就是電漿效應。然而，此效應的單位長度相位變化極小， 為了降低其驅動電壓，所需的調製器長度就常常需要超過1mm。如此變會造成調制器操作速度的劣 化和晶片面積的增加。使用環型調制器是一個可能的解決方法，然而其超窄的光學頻寬和對製程變 異極差的容忍度，使得其商品化充滿了挑戰。 在此計畫中我們將開發一種新穎的光波導慢波結構有效解決一般慢波元件極窄的光學頻寬缺點， 並結合行波式電極設計，展示一種新型的高速、高線性度、低驅動電壓的邁克生干涉光電調製器。我 們也會利用此種新穎的光波導慢波結構展示高速的光相位調制器，此元件將會和我們所開發的高功 率光偵測器整合，並應用於矽晶光電平台的相位陣列天線。 ;Recently, due to the tremendous progress in the fabrication processes of Silicon integrated circuit (Si-IC), the Si photonic technology has attracted lots of attention. A lots of research institutes in different countries have spent a lot of efforts to mimic the successful experience in Si foundry to photonic integrated circuit (PIC). One of the most important applications in Si-photonic technology is the microwave-photonic system. By use of the photonic technology, the performance of the traditional microwave-millimeter wave system might be greatly enhanced. However, due to the additional electrical-optical-electrical conversion processes in such kind of approach, the whole system would become more complex and might be more bulky. The goal of such project is to integrate the microwave-photonic system onto a single chip by use of Si-photonic technology without sacrificing the system performance. To have a high-speed, high-linearity, and low-driving-voltage optical modulator is very important in the microwave-photonic system. The most common mechanism to realize the optical phase modulation in Si-photonic platform is plasma effect induced by injected carriers. Nevertheless, the plasma induced phase change is very weak and in order to reduce the driving-voltage, the required device length must be over 1 mm. This would degrade the modulation speed of modulator and increase the chip area. By using ring modulator is one possible solution, however such device structure has problem in commercialization due to that its optical operation window has poor tolerance in process variation. In this project, we will develop a novel optical slow-wave waveguide, which can overcome the problem in narrow optical bandwidth of traditional slow-wave device. We will further combine it with traveling-wave electrodes to demonstrate a novel Mach-Zehnder modulator (MZM) with high-speed, high-linearity, and low-driving-voltage performances. We will also utilize such novel optical slow-wave structure to disclose a high-speed optical phase shifter. Such key component would be integrated with our new developed high-power photodiode and have important applications in beam-steering phase array antenna on Si-photonic platform.
