Multiwavelength Fiber Lasers and Their Applications in Wavelength-division Multiplexed Passive Optical Networks

摘要 随着各种宽带业务的不断涌现，用户对接入带宽的需求不断增长，宽带化已成为接入网发展的最显著特征，预计在未来3－5年内单个用户接入带宽将超过100Mb/s，至2020年带宽需求将达1Gb/s。然而，现有以xDSL为主的同轴电缆宽带接入方式已很难满足用户对高带宽以及安全性等方面的要求，全光纤接入无源光网络（PON）能提供高带宽、高速率、高质量的“三高服务”，被视为下一代宽带接入技术的代表——“最后一公里”的最终解决形式。目前，发达国家已利用EPON或GPON等时分复用无源光网络（TDM－PON）实现宽带接入，但采用时分复用技术导致单个用户最终分享带宽仅30～80Mb/s。伴随“三网融合”及各...Abstract Due to the explosive growth of Internet traffic and the emergence of many new broadband Internet services and applications such as IPTV, video conferencing and online shopping, the bandwidth demand has been tremendously increased and the trend will continue. It is predicted that the access bandwidth demand for each user will reach 100 Mb/s in 2012, and more than 1 Gb/s in 2020. However, ...学位：工学博士院系专业：信息科学与技术学院通信工程系_通信与信息系统学号：2332006015338

Towards visible-wavelength passively mode-locked lasers in all-fibre format

锁模皮秒/飞秒光纤激光器具有小型化、光束质量好、稳定性佳、低成本且免维护等优点，然而，目前被动锁模光纤激光器工作波段仍主要局限在近红外1-2 μm光谱区域，在可见光波段（380-760 nm）却几乎未有进展。如何实现可见光被动锁模光纤激光器，直接产生小型化、低成本且高性能的可见光超快激光，是一直困扰超快激光研究领域的一个难题。罗正钱教授课题组通过数值求解金兹伯格-朗道方程，发现耗散孤子谐振机制利于可见光波段超大色散光纤腔被动锁模脉冲的稳定建立。基于数值模拟的结果，该研究成果是在可见光范围内向小型化超快光纤激光器迈出的重要一步。将为可见光超快光纤激光在精密光谱学、生物医学、显微成像、光通信、科学研究等领域的应用奠定基础，具有很好的研究潜力和应用价值。厦门大学为该论文的第一署名单位，电子科学与技术学院博士研究生邹金海为论文第一作者，罗正钱教授为论文通讯作者。Mode-locked fibre lasers (MLFLs) are fundamental building blocks of many photonic systems used in industrial, scientific and biomedical applications. To date, 1–2 μm MLFLs have been well developed; however, passively mode-locked fibre lasers in the visible region (380–760 nm) have never been reported. Here, we address this challenge by demonstrating an all-fibre visible-wavelength passively mode-locked picosecond laser at 635 nm. The 635 nm mode-locked laser with an all-fibre figure-eight cavity uses a Pr/Yb codoped ZBLAN fibre as the visible gain medium and a nonlinear amplifying loop mirror as the mode-locking element. First, we theoretically predict and analyse the formation and evolution of 635 nm mode-locked pulses in the dissipative soliton resonance (DSR) regime by solving the Ginzburg-Landau equation. Then, we experimentally demonstrate the stable generation of 635 nm DSR mode-locked pulses with a pulse duration as short as ~96 ps, a radio-frequency signal-to-noise ratio of 67 dB and a narrow spectral bandwidth of 1 nm) and modulated optical spectrum. This work represents an important step towards miniaturized ultrafast fibre lasers in the visible spectral region.This work was supported by the Major Research Plan of the National Natural Science Foundation of China (91750115), Equipment Pre-research Project of Equipment Development Department of Central Military Commission (61404140112), and Natural Science Foundation of Fujian Province for Distinguished Young Scientists (2017J06016).Prof. Zhengqian Luo acknowledges the Program for Young Top Notch Talents of Fujian Province and the Program for Nanqiang Young Top Notch Talents of Xiamen University.该研究受到国家自然科学基金、福建省杰出青年基金、福建省特支‘双百’青年拔尖人才项目以及厦门大学南强青年拔尖人才项目的支持

3μm中红外稀土掺杂光纤激光器研究进展

工作波长位于3μm的中红外光纤激光器,因其位于水分子以及诸多气体和生物分子的吸收峰,被广泛应用于激光医疗、遥感、大气监测、光谱学和军事领域。本论文首先介绍了3μm光纤激光器常用的光纤基质和稀土增益离子,分析了3μm稀土掺杂光纤激光器的工作原理,并且从不同研究视角回顾了3μm稀土掺杂光纤激光器的研究进展。其中,锁模中红外光纤激光器、小型化全光纤中红外激光器和3-4μm更长波长的中红外光纤激光器是目前研究的主要趋势和热点。随着3μm中红外光纤激光相关技术的迅速发展,结构更紧凑、性能更优异的3μm光纤激光器不断涌现,必将大大推动其商业化和实用化的进程,并更好地满足不同领域的应用需求

基于石墨烯可饱和吸收体的脉冲光纤激光器研究进展

单层石墨烯是一种具有独特电学及光学特性的二维碳材料,尤其是在光学应用方面,它对可见光到近红外波段范围内光波仅有2.3%的线性吸收.由于石墨烯的独特性质,使得它可以作为一种具有超快响应时间以及超宽带工作特性的可饱和吸收体.本综述将展开石墨烯的线性及非线性光学特性分析,并重点阐述基于石墨烯可饱和吸收体的调Q及锁模光纤激光器研究进展,并指出厦门大学光电子技术研究所近几年来在这一方面所取得的成果.国家自然科学基金(61275050);高等学校博士学科点专项科研基金(20120121110034

数值优化3~5 μm中红外ZBLAN光纤拉曼激光器的研究

3~5μm中红外激光在国防、医疗、自由空间光通信及材料加工等领域具有重要的应用价值。本文提出利用发展较成熟的2.7~2.9μm掺Er激光作为拉曼抽运源,ZBLAN光纤作为拉曼增益介质,为获得激射波长灵活、结构紧凑的3~5μm中红外激光提供一种可行方法。依据光纤拉曼激光器的非线性耦合方程组,数值分析并优化设计了3~5μm中红外ZBLAN光纤一级/二级拉曼激光器。主要研究了ZBLAN光纤长度和输出镜反射率等参数对拉曼激光阈值及输出功率的影响。数值结果表明:1)拉曼阈值随着输出镜反射率的增大而明显下降,且存在最优的ZBLAN光纤长度使一级拉曼阈值最低(4.15 W);2)为获得最高拉曼激光输出功率,最优输出镜反射率分别为84%~98%(一级)和42%~60%(二级),最优ZBLAN光纤长度分别为6.7~8.9 m(一级)和1.5~2.4 m(二级),最优斜率效率分别高达72.36%(一级)和34.06%(二级)。研究工作在一定程度上可为实验研究此类中红外拉曼激光器提供理论指导。国家自然科学基金(61107038);厦门大学大学生创新创业实训项

Numerical Optimization of 3~5 μm Mid-Infrared ZBLAN Fiber Raman Lasers

3~5μM中红外激光在国防、医疗、自由空间光通信及材料加工等领域具有重要的应用价值。本文提出利用发展较成熟的2.7~2.9μM掺Er激光作为拉曼抽运源,zblAn光纤作为拉曼增益介质,为获得激射波长灵活、结构紧凑的3~5μM中红外激光提供一种可行方法。依据光纤拉曼激光器的非线性耦合方程组,数值分析并优化设计了3~5μM中红外zblAn光纤一级/二级拉曼激光器。主要研究了zblAn光纤长度和输出镜反射率等参数对拉曼激光阈值及输出功率的影响。数值结果表明:1)拉曼阈值随着输出镜反射率的增大而明显下降,且存在最优的zblAn光纤长度使一级拉曼阈值最低(4.15 W);2)为获得最高拉曼激光输出功率,最优输出镜反射率分别为84%~98%(一级)和42%~60%(二级),最优zblAn光纤长度分别为6.7~8.9 M(一级)和1.5~2.4 M(二级),最优斜率效率分别高达72.36%(一级)和34.06%(二级)。研究工作在一定程度上可为实验研究此类中红外拉曼激光器提供理论指导。3~5 μm mid- infrared lasers have attracted much attentions due to their wide applications in defences, medicine, free-space optical communication and materials processing.A new scheme for obtaining a3~5 μm flexible-wavelength, compact mid-infrared Raman fiber laser is proposed, using a 2.7~2.9 μm Erdoped fiber laser as Raman pump source and a ZBLAN fluoride fiber as Raman gain medium.Based on the nonlinear coupling equations of Raman fiber lasers, the 3~5 μm mid- infrared ZBLAN fiber 1st/2nd- order Raman lasers are numerically analyzed and optimized.The theoretical optimization is mainly focused on the effects of ZBLAN fiber length and output-mirror reflectivity on the Raman laser threshold and output power.The numerical results show: 1) the Raman laser threshold significantly reduces with the increase of the outputmirror reflectivity, and there always exists the optimized ZBLAN fiber length for the lowest Raman threshold(4.15 W); 2) in order to obtain the high-power Raman laser output, the optimized reflectivities of output mirror are 84~98%(1st-order) and 42~60%(2nd-order), the optimized ZBLAN fiber lengths are 6.7~8.9 m(1st-order)and 1.5~2.4 m(2nd-order), respectively.The optimized slope conversion efficiencies can be as high as 72.36%(1st-order) and 34.06%(2nd-order).These results could provide a theoretical guidance for such mid-infrared fiber Raman lasers.国家自然科学基金(61107038); 厦门大学大学生创新创业实训项

倏逝场作用氧化石墨烯大能量耗散孤子锁模双包层光纤激光器

报道了倏逝场作用氧化石墨烯的可饱和吸收体用于锁模掺镱双包层光纤激光器,产生大能量151.54nJ耗散孤子.利用熔锥光纤倏逝场诱导沉积氧化石墨烯方法,所制备的可饱和吸收体不仅拥有耐高功率、光纤兼容等优点;而且,熔锥光纤引入光带通滤波,有益于耗散孤子在光纤激光腔中形成.同时结合光纤包层泵浦技术,高脉冲能量耗散孤子在锁模掺镱双包层光纤激光器中被获得,产生的耗散孤子单脉冲能量高达151.54nJ,重复频率271.4kHz,信噪比57dB.国家自然科学基金(61275050);高等学校博士学科点专项科研基金(20120121110034

连续输出1.60W/473nm直腔蓝光激光器

报道了LD端面泵浦Nd∶YAG晶体,LBO腔内倍频473 nm全固态直腔蓝光激光器.根据谐振腔稳定性理论,利用简单的平-平腔直接测得不同泵浦功率下的热焦距值.通过数值计算分析了不同热焦距下,Nd∶YAG与LBO晶体中的腰斑半径以及LBO中光腰的位置,并在准三能级系统模型和倍频理论的指导下优化激光腔体结构,使激光器实现最佳的模式匹配和倍频效率,得到高效的蓝光激光输出.激光阈值为1.92 W;当泵浦激光功率为20.58 W时,473 nm蓝光的输出功率为1.60 W,光-光转化效率为7.8%

Novel Tunable Fiber Optic Edge Filter Based on Modulating Chirp Rate of pi-Phase-Shifted Fiber Bragg Grating

We propose and experimentally demonstrate a novel tunable fiber optic edge filter based on modulating the chirp rate of a pi-phase-shifted fiber Bragg grating (FBG) operated in reflection mode. The phase shift induced notch in the reflection spectrum is utilized as the edge filter. The dependence of the pi-phase-shifted FBG's spectral response on the chirp rate has been numerically studied in detail and experimentally confirmed for the first time. The linear wavelength range of this edge filter can be tuned by changing the chirp rate of FBG. A fiber optic edge filter is further obtained experimentally and tested as a wavelength interrogator, which is in a good agreement with numerical results. The proposed edge filter has advantages of simple-structure, cost-effectiveness, high sensitivity, and flexible tunable, thus opening up some applications, especially as wavelength interrogator in small wavelength range

Switchable and tunable multiple-channel erbium-doped fiber laser using graphene-polymer nanocomposite and asymmetric two-stage fiber Sagnac loop filter

A high-performance multiple-channel erbium-doped fiber laser (EDFL) is proposed and experimentally demonstrated, using graphene-polymer nanocomposite as a multiwavelength equalizer and an asymmetric two-stage polarization-maintaining fiber (PMF) Sagnac loop as a flexible comb filter. At first, the filtering characteristics of the PMF Sagnac loop filter (SLF) are investigated. Both theoretical and experimental results show that it can provide a flexibly switchable and tunable comblike filtering. Then, the two-stage PMF SLF is inserted into a graphene-assisted EDFL cavity for generating multiwavelength oscillation. The extreme-high third-order optical nonlinearity of graphene is exploited to suppress the mode competition of the EDFL, and a stable multiple-channel lasing is observed. By carefully adjusting the polarization controllers in the two-stage PMF SLF, not only can the lasing-line number per channel be switchable between single and multiple wavelengths, but also the wavelength spacing in the triple-wavelength condition can be tunable. In the case of triple wavelengths per channel, up to 12 wavelengths with four channels stable oscillations can be achieved. The multiple-channel EDFL can keep a high extinction ratio of >40 dB and a narrow linewidth of <0.01 nm. (C) 2011 Optical Society of Americ