全保偏双波长锁模掺铒光纤激光器  

All-Polarization-Maintaining Dual-Wavelength Mode-Locked Er-Doped Fiber Lasers

作　　者：白松涛 郭政儒 杨康文 夏宇 贺明洋 郝安庆 李敏 Bai Songtao;Guo Zhengru;Yang Kangwen;Xia Yu;He Mingyang;Hao Anqing;Li Min(School of Optical Electrical and Computer Engineering,University of Shanghai for Science and Technology,Shanghai 200093,China;State Key Laboratory of Precision Spectroscopy,East China Normal University,Shanghai 200062,China;Jinan Institute of Quantum Technology,Jinan,Shandong 250101,China)

机构地区：[1]上海理工大学光电信息与计算机工程学院,上海200093 [2]华东师范大学精密光谱科学与技术国家重点实验室,上海200062 [3]济南量子技术研究院,山东济南250101

出　　处：《光学学报》2024年第13期163-170,共8页Acta Optica Sinica

基　　金：国家自然科学基金(62375173,61927813)。

摘　　要：本文提出并演示了一种基于半导体可饱和吸收镜的全保偏双波长锁模掺铒光纤激光器。具有偏振相关损耗的波分复用器与保偏掺铒光纤以一定角度拼接,产生周期性Lyot滤波效应,在同一个线性腔中实现了单、双波长两种锁模状态的切换输出。通过改变激光器参数(泵浦功率和偏振态),激光腔内的光沿着保偏光纤的不同轴向传输产生波长相关的相位差,双波长锁模可获得异步和同步两种锁模状态,异步双波长锁模中心波长分别为1563.0 nm和1568.4 nm,重复频率差为319 Hz。由于该激光器采用全保偏结构,锁模脉冲的环境稳定性高。该研究可以为搭建结构简单、易重复的全保偏双波长激光器提供新的设计方案。Objective Dual-comb spectroscopy(DCS) based on optical frequency comb(OFC) has attracted much attention in recent years because of its high sensitivity, high resolution, and high sampling rate. At present, there are three technical routes to achieve DCS: coherent DCS, adaptive DCS, and single-cavity DCS. The single-cavity DCS system is constructed by two pulse sequences with a small repetition frequency difference from a single laser, and the two mode-locked pulse sequences share part or the whole laser cavity, which suppresses common-mode noise and maintains good coherence, making the system possess simple structure, high coherence, and easy integration. Given the advantages above, it has become one of the research hotspots in recent years.Methods A linear all-polarization-maintaining dual-wavelength mode-locked erbium-doped fiber laser is used in the experiment. The semiconductor saturable absorber(SESAM) is used to assist mode-locking, and the wavelength division multiplexer(WDM) with polarization-dependent loss is fused with the polarization-maintaining erbium-doped fiber to generate a periodic Lyot filter. By adjusting the pump power and the polarization state in the cavity, the laser can switch between single-wavelength and dual-wavelength mode-locked states.Results and Discussions When the pump power is increased to 60 mW, the laser begins to output continuous light near the central wavelength of 1560 nm. When the pump power is increased to 106 mW, and the wave plate is rotated to adjust the polarization state in the cavity, the laser begins to exhibit a mode-locked state. At this time, the mean output power of the fiber laser is 1.03 mW. In the single-wavelength mode-locked state, the central wavelength of the two pulse sequences is 1564.2 nm, the bandwidth of 3 dB is 2.8 nm, and there are obvious Kelly sidebands on both sides of the spectrum [Fig. 2(a)]. The repetition frequency is 22.81 MHz, the signal-to-noise ratio(SNR) is 52 dB, and the spectrum diagram in the 550 MHz range indicates that the mode-lo

关 键 词：光纤激光器 半导体可饱和吸收镜 全保偏 异步双波长 同步双波长 

分 类 号：O437[机械工程—光学工程]