多波长半导体锁模激光器集成芯片研究

High repetitive rate multiwavelength short pulse light source is a key enabling technology in future WDM and WDM-PON photonic networks, where it can replace the hundreds of discrete lasers individually addressing each WDM channels, resulting in significant cost savings. It also has broad applications in diverse fields such as high speed optical sampling, ultrafast optical processing, and microwave photonics. Traditional approaches for generating multiwavelength short pulse light sources however all require expensive and bulky optical systems with discrete components. We propose a novel monolithically integrated multiwavelenth semiconductor mode locked laser chip in the InP material. Photonic Integrated circuit (PIC) integrating multiple photonic components monolithically onto the same chip is an important technology tend in recent years. By creating system on chip solutions it can dramatically reduce system cost, footprint, improve reliability and expand system functionalities. Critical scientific problems we plan to investigate in depth include mode partition noise effect between wavelength channels, pulse shaping carrier dynamics inside electro-absorptive modulator (EA) under multiwavelength pulse injection conditions, timing jitter stability under electrical hybrid mode locking and optical injection locking, and optical clock recovery. Furthermore we plan to quantitatively analyze effects of active-passive interface quality on mode locking behaviors. Our work has the potentials for delivering a highly compact, low cost, low noise PIC multiwavelength pulsed light source chip solution for the future mass deployment. This design represents original research work and has never been reported in literature.

高速率多波长短脉冲光源是未来WDM及WDM-PON光网络中的关键器件。使用单个多波长短脉冲光源可取代WDM技术中数以百计的独立光源器件，从而大幅降低系统成本。多波长短脉冲源在高超快光信息处理以及微波光子学等领域也有广泛应用。传统的多波长短脉冲方案中普遍使用分立光学元件，导致系统成本高昂、体积庞大。本项目基于InP基半导体光子集成芯片技术，准备开展新型高速率多波长短脉冲光源的研究，通过集成技术大幅度降低多波长脉冲源的器件成本和体积，并提高系统可靠性。计划通过相关实验与模拟深入研究与其设计相关的若干科学问题：多波长信道间的模式分配噪声问题；饱和吸收区在多波长光脉冲注入下的时域载流子动态机制及短脉冲整形机理；电混合锁模及光注入锁模状态下脉冲输出的稳定性和定时抖动问题；多波长光信号时钟恢复机理；有源-无源波导集成界面对锁模稳定的影响等。此芯片集成方案在国内外文献中尚无报道，具有较高原创性。

高速率多波段短脉冲光源是未来WDM及WDM-PON的光通讯网络所需关键器件技术。使用单个高速率多波段短脉冲光源可取代WDM技术的光通讯网络中数以百计的独立光源器件，从而大幅降低器件成本。同时在高速光采样，超快光信息处理，微波光子学等领域都有较为广泛的应用。此类光源技术的传统方法需要较为昂贵，笨重的使用多个分立元件的光学系统。.项目研究是围绕我们首次提出的基于阵列波导光栅的单片集成半导体多波长锁模激光器芯片开展的。我们通过对集成芯片的关键科学问题和制作工艺的系统研究，在国际上首次成功研制出多种基于阵列波导光栅的光子芯片，如1×4 400GHz通道间隔的InP基平坦化响应阵列波导光栅；和基于阵列波导光栅的1×8多波长激光器芯片等。并最终成功研制了我们提出的单片集成的多波长锁模激光器芯片。该芯片可以实现四波长的脉冲宽度均匀、低时间抖动的短脉冲输出，并在外加时钟信号下实现同步。该集成光子芯片具有体积小、成本低等优点，是未来光通信系统中多波长脉冲光源的一个很好的解决方案。