基于全正色散光纤锁模激光器的波长可调光谱平顶单腔双光梳  

Single⁃Cavity Dual⁃Comb with Tunable Wavelength and Flat⁃Topped Spectrum Based on All⁃Normal Dispersion Fiber Mode⁃Locked Laser

作　　者：宋鹏枼 陶家宁 应鹏润 靳昊澍 谢海洋 侯磊[1] 许思源 刘辉[1] Song Pengye;Tao Jianing;Ying Pengrun;Jin Haoshu;Xie Haiyang;Hou Lei;Xu Siyuan;Liu Hui(Institute of Photonics&PhotonTechnology,Northwest University,Xi’an 710127,Shaanxi,China)

机构地区：[1]西北大学光子学与光子技术研究所,陕西西安710127

出　　处：《中国激光》2024年第14期80-86,共7页Chinese Journal of Lasers

基　　金：国家自然科学基金(62005215);陕西省自然科学基础研究计划(2019JCW03,2024JC-BMS-507);陕西省教育厅科研计划(23JK0690);西安市科技计划(202005YK01)。

摘　　要：报道了一种由线性腔全正色散光纤锁模激光器产生的波长可调谐且光谱为平顶状的单腔双光梳光源。该激光器输出两个重复频率略微不同的光频梳,具有偏振正交、中心波长可同时调谐,及光谱呈平顶且重叠等特点。在共腔作用下,重复频率的波动被抵消80%,自由运转条件下35 min内的重复频率差的漂移量被压缩至赫兹量级。在保持锁模稳定的条件下,中心波长可调谐范围大于10 nm,平顶光谱带宽约为4 nm。该双光梳光源兼具波长可调谐与光谱呈平顶状的特点,为波长可调谐的双光梳光谱提供了新的制备方案。Objective Dual-comb mode-locked lasers are emerging laser sources that have attracted significant attention in the fields of dualcomb spectroscopy, optical sensing, and absolute-distance measurements. In recent years, the use of dual-comb spectroscopy to detect fast dynamic processes has become a new development trend but has also presented corresponding technical challenges. The detection of fast processes requires the shortest possible detection time and high update speed while maintaining a certain spectral bandwidth, signal-to-noise ratio, and accuracy. A high repetition rate and large repetition rate difference are essential for improving the detection speed of dual-comb spectroscopy, which can reach a time resolution on the order of nanoseconds. However, this may reduce the spectral bandwidth. Another approach is to use a tunable wavelength in a dual-comb light source. In this study, we present a dual-comb laser with tunable wavelength and flat-topped spectrum generated from an all-normal dispersion linear-cavity fiber laser.This novel dual-comb light source with flat-top spectral characteristics and tunable wavelength provides a scheme for fast segmented scanning dual-comb spectroscopy that has good reference value for rapid dual-comb spectroscopic applications.Methods The hybrid cavity investigated in our study is linear and consists of a fiber and free space, as shown in Fig. 1. The cavity is 3.97 m in length. In the fibered section, a single-mode ytterbium-doped fiber(YDF) with a length of 0.4 m is pumped by a 976-nm diode through a single-mode fiber wavelength division multiplexer. The group velocity dispersion introduced by the YDF is 23 ps2/km. The output of the fiber output coupler is 40% of the intra-cavity power. At one end of the cavity, a semiconductor saturable absorber mirror(SESAM) is attached to the fiber jumper, which has a polarization-maintaining fiber(PMF) tail of 0.75 m in length. The SESAM, which has a modulation depth of 30% and relaxation time of 500 fs, is used to achieve self-start

关 键 词：激光器 锁模 全正色散 双光梳 

分 类 号：O436[机械工程—光学工程]