窄线宽激光器技术及进展(特邀)  

Narrow Linewidth Laser Technology and Development(Invited)

作　　者：朱涛[1] 党来杨 李嘉丽 兰天意 黄礼刚 史磊磊[1] ZHU Tao;DANG Laiyang;LI Jiali;LAN Tianyi;HUANG Ligang;SHI Leilei(Key Laboratory of Optoelectronic Technology&Systems(Education Ministry of China),Chongqing University,Chongqing 400044,China)

机构地区：[1]重庆大学光电技术及系统教育部重点实验室,重庆400044

出　　处：《光子学报》2022年第8期55-75,共21页Acta Photonica Sinica

基　　金：国家自然科学基金(No.61635004);国家杰出青年科学基金(No.61825501);重庆市自然科学基金创新研究团队资助项目(No.cstc2020jcyj-cxttX0005)。

摘　　要：窄线宽激光器具有极高的光谱纯度、极大的峰值谱密度、超长的相干长度和极低的相位噪声,因而作为核心光源在引力波探测、光学时钟、冷原子物理、相干光通信、光学精密测量以及微波光子信号处理等领域中具有重要应用。激光及应用研究的深入开展,对激光器的综合参数性能提出了更高的要求,窄线宽激光器正沿着线宽超窄、时频超稳、波长可调和波长可扫等方向发展。立足激光腔内自发辐射与受激辐射的互作用原理,对激光腔的架构进行深入研究是目前实现窄线宽激光参数极致调控的重要研究思路之一。为了抑制自发辐射对受激辐射能量的扰动,激光自发明以来,逐渐发展了主腔激光、固定外腔反馈激光和自适应分布反馈激光等构型的激光器。其中,基于自适应分布反馈的激光架构主要是基于分布反馈对主激光腔内自发辐射的时空随机微扰进行深度抑制,达到对激光线宽进行波长自适应压缩的目的。本文首先介绍了窄线宽激光器的应用需求与架构演化脉络,随后介绍了主腔激光和固定外腔反馈激光的研究进展。然后重点介绍了新近发展的自适应分布反馈窄线宽激光器,对该类新型激光器的物理思想、核心器件和系统性能进行了分析和讨论。最后以分布式光纤传感、激光相干通信以及片上光信息处理作为典型应用领域介绍了窄线宽激光器的潜在应用,并展望了窄线宽激光器的发展前景和未来趋势。Narrow linewidth lasers have extremely high spectral purity,high peak spectral density,ultralong coherence length and extremely low phase noise,so they are used as core light sources in fields of gravitational wave detection,optical clocks,cold atom physics,coherent optical communication,optical precision measurement and microwave photonic signal processing.With the development of laser and its application research,higher and higher requirements are placed on the comprehensive parameter performance of lasers.Narrow linewidth lasers are developing in the direction of ultra-narrow linewidth,ultra-stable time-frequency parameter and wavelength arbitrary tunability.Among them,the laser linewidth is the key factor that determines laser coherence,and it has always been the focus of scientists′research on laser technology.The essence of the existence of linewidth is that the laser will be affected by the phase and intensity disturbances caused by spontaneous radiation in the gain during operation,which makes the laser output signal inherently broadened by Gaussian white noise.In addition,the laser is also easily affected by the classical noise caused by the temperature change and vibration in the external environment,which further widens the laser linewidth.The above-mentioned factors have greatly reduced the coherence of the laser,thus limiting the development of the laser in promoting scientific research and industrial application to a great extent.Therefore,laser linewidth compression technology has become a key scientific issue for obtaining high-coherence light sources.At present,lasers with fiber-doped rare earth ions and semiconductors as gain have the advantages of long life,small size,low cost,high reliability,and easy industrialization,and have become the most studied and widely used solid-state lasers.However,due to the lack of control technology,the linewidth of conventional short-cavity fiber and semiconductor lasers is usually maintained at the order of tens of kHz or even MHz,and it is difficult to meet

关 键 词：激光 窄线宽 相干性 自适应分布反馈 瑞利散射 光纤传感 相干通信 片上光子 

分 类 号：O432.11[机械工程—光学工程]