稳定单纵模运转的低噪声环形复合腔光纤激光器  

Low-Noise Compound Ring Cavity Fiber Laser with Stable Single-Longitudinal-Mode Operation

作　　者：刘昊炜 张骥 魏珊珊 姚波 毛庆和 Liu Haowei;Zhang Ji;Wei Shanshan;Yao Bo;Mao Qinghe(Anhui Key Laboratory of Photonics Devices and Materials,Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei,Anhui 230031,China;University of Chinese Academy of Sciences,Beijing 100049,China;University of Science and Technology of China,Hefei,Anhui 230026,China)

机构地区：[1]中国科学院合肥物质科学研究院安徽光学精密机械研究所光子器件与材料安徽省重点实验室,安徽合肥230031 [2]中国科学院大学,北京100049 [3]中国科学技术大学,安徽合肥230026

出　　处：《中国激光》2021年第5期218-225,共8页Chinese Journal of Lasers

基　　金：国家重点研发计划(2017YFB0405100,2017YFB0405200);中国科学院战略性先导科技专项(B类)(XDB21010300);国家自然科学基金(61805258,61377044);先进激光技术安徽省实验室主任基金(20191001)。

摘　　要：报道一种可实现稳定单纵模运转的低噪声环形复合腔掺铒光纤激光器。利用保偏光纤抗外界扰动能力强的特性,精细地优化复合腔参数以拓宽有效纵模间隔。对经隔震绝热封装后的激光器采取温度补偿,可对复合腔自由光谱范围(FSR)进行微调,使得复合腔激光器可更精准地运用Vernier效应来有效抑制跳模,进而该激光器可实现14 h以上无跳模的稳定单纵模连续运转,输出激光的信噪比高达80 dB,线宽窄至400 Hz。此外,还首次测量了环形复合腔掺铒光纤激光器在自由运转下宽频段内强度噪声和频率噪声特性,测量结果表明,该激光器在1 mHz~1 MHz宽频段内的强度噪声和频率噪声低,在1 mHz~10 Hz频段,强度噪声和频率噪声均优于典型分布Bragg反射(DBR)光纤激光器的噪声水平,且弛豫振荡频率也更低。Objective Low-noise narrow-linewidth single-longitudinal-mode(SLM)lasers have several important applications in many fields,such as gravitational wave detection,atomic and molecular physics,time and frequency transfer,and precision measurement.Currently,SLM fiber lasers are divided into three main types:distributed feedback,distributed Bragg reflection(DBR),and ring cavity laser.Among them,the ring cavity laser,which employs a long cavity design,facilitates increase in cavity gain to improve output power using relatively high-gain fibers.A ring cavity laser can also be used in other applications such as frequency tuning and feedback control by simply inserting optical components into a cavity.Moreover,the Q-value of a fiber-laser resonator can be increased by employing a long ring cavity.This long cavity helps in obtaining a narrow free-running laser linewidth and reduces the relaxation oscillation frequency of the laser.This is useful in suppressing a relaxation oscillation peak through photoelectric feedback control.However,a long ring cavity is easily affected because of external-environment noise disturbances,which leads to SLM instability,e.g.,mode hopping.Thus far,the achieved continuous operation time of a free-running compound ring cavity fiber laser without mode hopping is only several hours.Therefore,although in principal,a fiber-laser source exhibits excellent performance,it cannot meet practical application requirements.In this study,a low-noise narrow-linewidth-ring erbium-doped fiber laser operating in a SLM and maintaining its polarization is reported.Methods A polarization-maintaining(PM)fiber′s strong ability to resist environmental disturbances allows the parametric optimization of a compound ring cavity through repeatable experiments in a laboratory.During experimental optimization,Fabry-Perot(F-P)type very narrow resonant transmission peaks of a secondary cavity are used to filter potentially oscillating dominant longitudinal modes from a large number of nearby main-cavity modes.Then,notch b

关 键 词：激光器 光纤激光器 环形复合腔 保偏光纤 单纵模 线宽 噪声 

分 类 号：TN248[电子电信—物理电子学]