集成电光频率梳研究进展(特邀)

Progress in integrated electro-optic frequency combs(Invited)

光学频率梳是由一系列离散且等间隔分布的频率成分所组成的光谱结构,作为光谱分析的天然刻度尺,其已广泛应用于光谱学、精密测量、光通信、传感等多个领域。光学频率梳根据其产生技术可分为基于锁模激光器的光学频率梳、克尔微腔光学频率梳、电光频率梳。电光频率梳由于其频率间隔可调、梳齿功率较高、可实现微波到光波的转换等优势,得到了充分发展。但传统电光频率梳的产生器件存在体积大、功耗高的缺点,限制了其进一步应用。随着微纳加工技术的不断发展,越来越多的材料应用于片上集成光学器件,包括硅、氮化硅、氮化铝、磷化铟、铌酸锂、砷化铝镓等。集成电光频率梳器件具有体积小、功耗低等优势,是构建光电集成芯片的重要器件。文中旨在对集成电光频率梳的研究现状进行综述,首先介绍光学频率梳的类型,并详细论述电光频率梳的产生机制;其次介绍产生集成电光频率梳的材料平台、相应的光梳性能指标及其应用;最后基于目前集成电光频率梳领域存在的问题,对未来的研究趋势做出展望。

Optical frequency comb(OFC)is the spectrum structure composed of a set of discrete and equally spaced frequency components,which has been widely used in many areas such as spectroscopy,precision measurement,optical communication and sensing as the natural scale for spectral analysis.According to its generation methods,OFC can be generated in three ways,including mode-locked laser based OFC,Kerr microresonator OFC and electro-optic frequency comb(EOFC).EOFC has been greatly developed because of its advantages including remarkable tunability of frequency spacing,high comb line power,as well as the accessible conversion from microwave to optical wave.However,there are some drawbacks in conventional EOFC generator,for instance,the bulk size and required high power,which limit its further development.As the micro/nanofabrication technology gradually grows,more and more materials are applied into integrated chip-scale optical devices,including Si,Silicon Nitride,Aluminum Nitride,Indium Phosphide,Lithium Niobate and Aluminium Gallium Arsenide.Integrated EOFC possesses the excellent characteristics,such as small volume and low power consumption,which is an important device for optoelectronic integrated chip.The research status of the integrated EOFC is reviewed in this paper.First,the classification of optical frequency comb,as well as detailed content about generation mechanism of EOFC are introduced.Next,the information comprising various material platforms,corresponding devices performance metrics and applications about EOFC is presented.Finally,the future research directions are prospected in view of the existing problems of integrated EOFC.