基于硅光微环调制器的超宽带脉冲产生与调制技术研究

Optoelectronic device for UWB-IR generation and modulation is the key technology for the next generation personal area wireless communication system. Most of the current research of generation and modulation of UWB-IR are based on discrete components which have large footprint, high power consumption and cost. We shall apply the silicon photonic integration technology to microwave photonics in this project. Since the silicon microring can achieve both frequency discrimination and high speed modulation, the UWB pulses could be generated and modulated in a single ring resonator. We shall design the silicon nanophotonic circuits in which the microring converts the phase modulated signal to intensity modulated signal. Hence, the monocycle pulse and higher order UWB pulse could be generated in the microring resonator. Furthermore, the microring could achieve >20Gbit/s modulation speed by optimized waveguide doping and electrode design. As the key element of this device, microring resonator could simultaneously generate the UWB pulses and achieve either amplitude or phase modulation of the generated pulses. The proposed project includes theoretical investigation, device design, device fabrication and testing in system. In the end of this project, we expect to provide theoretical analysis and key techniques for developing low-cost integrated components in the next generation wireless UWB technology.

用于产生并调制脉冲超宽带（UWB-IR）信号的光电子器件是发展下一代个人局域无线通信系统的核心。当前用光学方法产生和调制超宽带脉冲尚处在基于分立器件的研究阶段，器件尺寸大，功耗高，成本高。本项目将硅光子集成技术应用到微波光子学领域，利用硅基微环调制器频率鉴别和高速调制的特点，在同一个微环上同时实现脉冲生成和调制。通过设计以微环谐振腔为核心部分的硅基纳米光波导，实现相位调制到强度调制的转换，从而产生一阶和高阶UWB-IR信号。在此基础之上对微环谐振腔进行参杂，优化参杂浓度和电极设计，使其实现>20Gbit/s的高速调制。参杂的微环谐振腔作为核心部分既实现了UWB-IR的产生，又作为超宽带脉冲调制器实现强度和相位的调制。本项目的开展包括理论验证，器件设计，器件制备和系统测试。该课题的研究将为我国发展下一代无线超宽带技术提供原理论证和关键技术实现。

本项目针对片上脉冲超宽带（UWB-IR）信号的光学产生与调制问题开展了研究，得到了以下几个方面的研究成果：1）我们研究了基于片上光路产生高阶高斯脉冲超宽带信号的机理，首次提出了利用多个微环调制器和延时光路产生二阶、三阶、四阶高斯脉冲超宽带的新方法；2）通过对有源区波导的设计与优化，实现了消光比高（>20 dB），工作波长可调（调谐范围>FSR）、调制速率高（100 Gbit/s）的硅基微环调制器；3）利用非对称高斯光脉冲的延迟与叠加，首次通过单片集成的硅基光波导及锗探测器获得了二阶、三阶高斯脉冲超宽带信号，芯片尺寸小于0.6 mm×2 mm，这也是首个高阶高斯脉冲超宽带产生的硅光子芯片；4）研究了微环谐振波长的高速调制机理，提出了一种同时实现脉冲超宽带产生于调制的新方法，并首次实现了这两种功能的集成，使微环调制器在产生一阶高斯脉冲信号的同时能够进行2.5 Gbit/s强度和相位调制。.在本项目的支持下共发表学术论文24篇，其中包括Photonics Research, Journal of Lightwave Technology, Optics Letters, Journal of Selected Topics in Quantum Electronics, Optics Express 等16篇SCI期刊论，以及8篇EI会议论文。