Passive phase locking of an array of four fiber lasers by mutual injection locking

In this paper, we report the passive phase locking of a four fiber lasers array by mutual injection locking. The four fiber lasers are mutually injected by four 5/5/90 couplers. Through mutual injection locking, good coherence has been obtained in the far field. The four fiber lasers can operate at the same wavelength with a stable output power. This scheme is quite easy to implement and can be extended to combine more beams.     

Semiconductor pump laser technology

Recent progress in high-power semiconductor lasers for erbium-doped fiber amplifiers is described, focusing on 1.48-μm InGaAsP/InP lasers and 0.98-μm InGaAs/GaAs lasers. The experimental output powers exceed 200 mW (the maximum power was 325 mW) for 1.48-μm lasers, and simulation results indicate that over 400 mW could be obtained by optimizing parameters in strained-layer (SL) multiple-quantum-well (MQW) lasers. Stable operation over a few thousand hours under 100-mW power is demonstrated for liquid-phase-epitaxy-grown lasers, MQW lasers, and SL-MQW lasers grown by all-metal organic vapor-phase epitaxy (MOVPE). For 0.98-μm lasers, improvement in the fiber coupling efficiencies and long-term reliabilities are described. Their power coupled into a single-mode fiber has reached over 100 mW, with coupling efficiencies of approximately 40%. Although reliability seems to be one of the drawbacks compared with 1.48-μm lasers, stable operation for over 10,000 h at 50°C and 30 mW has been reported     

Development of Fiber Lasers and Their Applications

1 Introduction Fiber lasers have been developed for more than forty years since Snitzer!s proposal and the demonstration of Nd- doped fiber in 1961 [1]. But fiber lasers have not been attracted considerable attention until the develop- ment of the low- loss fiber fabrication technology and the high power semiconductor laser technology recently. Actually,it is the application and development of fiber communication technology that has promoted the rapid development of fiber laser. Fiber laser, …     

Er3+-Yb3+ and Er3+ doped fiberlasers

Single-mode fiber lasers operating at ~1.57 μm are described. Output powers of >2 mW are reported for laser diode pumped operation. Direct comparison is made between fiber lasers using sensitized erbium (Er³⁺ and Yb³⁺) and erbium on its own. The performance of Er³⁺-Yb³⁺ fiber lasers is analyzed in more detail as a function of fiber length. Both CW and Q-switched operations are studied and the results obtained demonstrate that practical sources at 1.5 μm are available from diode pumped Er³⁺ -Yb³⁺ systems     

Recent progress on ultrafast/ultrashort/frequency-stabilized erbium-doped fiber lasers and their applications

There are many kinds of fiber lasers in the 1.5 μm band using erbium-doped fiber amplifiers. Our group has been studying and developing advanced fiber lasers, such as 1) 10-40 GHz harmonically mode-locked fiber lasers, 2) femtosecond fiber lasers that use single-wall carbon nanotube (CNT)-doped polymers as a saturable absorber, and 3) frequency-stabilized fiber lasers that employ acetylene C2H2. We will describe recent progress on these fiber lasers and their applications in this article.     

Photonic crystal distributed feedback fiber lasers with Bragggratings

Two new types of optical fibers, where air-holes are running down their length, are considered for making fiber lasers with Bragg gratings. The mode areas for pump and signal in these fiber lasers may be either larger or smaller compared to the corresponding mode areas for fiber lasers based on standard step index fibers. This makes possible realization of fiber lasers with a low pump threshold (small mode area), and fiber lasers suitable for high-power applications (large mode area)     

Experiments on chaos synchronization in two separate erbium-dopedfiber lasers

Chaos synchronization in two separate erbium-doped fiber lasers through a 1.5-km-long fiber is experimentally demonstrated. Two identical erbium-doped fiber lasers are fabricated and modulated by an optical modulator near the relaxation oscillation frequency of the fiber laser. At this frequency, the two fiber lasers generate chaotic carriers. When the synchronization conditions such as cavity length, modulation frequency, and laser characteristics are satisfied, the two chaotic fiber lasers are synchronized     

锁模光纤激光器的研究进展

锁模光纤激光器因其紧凑小巧、成本低和光束质量好等优点,近年来获得了快速发展。根据锁模原理可将锁模光纤激光器分为三类:主动锁模光纤激光器、被动锁模光纤激光器、主被动混合锁模光纤激光器。本文对各类锁模光纤激光器的关键技术和研究进展作了较为详细的介绍,并展望了其应用前景。     

Highly stable low-noise Brillouin fiber laser with ultranarrow spectral linewidth

We demonstrate an all-fiber high-power single-frequency Brillouin fiber ring laser with maximum power of 100 mW at 1.55 /spl mu/m, which is actively stabilized by using the Pound-Drever-Hall frequency-locking scheme. Significant reduction (/spl sim/20dB) of both relative intensity noise and frequency noise was observed in the Brillouin Stokes radiation as compared with those noises of its pump source, a narrow-linewidth Er-doped fiber laser. Ultranarrow spectral linewidth of the Brillouin fiber lasers was investigated by both delayed self-heterodyne technique and heterodyne beat technique between two independent Brillouin fiber lasers.     

多点抽运的双包层光纤激光器数值分析研究

为了对多点抽运的高功率双包层光纤激光器进行深入的理论分析,从掺Yb双包层光纤激光器的速率方程和边界条件出发,对多点抽运的双包层光纤激光器的数值分析方法进行了研究。通过坐标比例变换和抽运光与激光的连续性边界条件变换,将多点抽运的高功率双包层光纤激光器的数值分析模型转化为两点边值问题,然后利用两点边值问题的数值分析方法有效地进行求解,得到了抽运光和激光沿双包层光纤的分布。通过对多点抽运的双包层光纤激光器进行数值分析,不仅得到了激光器的输出功率,还能够得到抽运光损耗以及激光损耗数值大小等数据,有助于多点抽运的双包层光纤激光器的优化分析和设计。结果表明,该数值分析方法对多点抽运的双包层光纤激光器的深入研究非常有意义。     

损耗对掺镱双包层光纤激光器输出特性的影响

本文分析了损耗对线形腔掺镱双包层光纤激光器输出特性的影响。对有损耗的线形腔掺镱双包层光纤激光器输出特性进行了数值分析,(当考虑光纤损耗时)得出了泵浦功率和正反向激光功率在2 0米长光纤处有近2W降低(泵浦功率为2 0W时)的结论。同时,文中给出了有损耗时的输出功率与光纤长度、泵浦功率和后镜反射率R2 的关系曲线。     

高功率GTWave光纤激光器研究进展

高功率GTWave光纤激光器是目前光纤激光器研究的一个热点。介绍了GTWave光纤的结构,并回顾了国内外高功率GTWave光纤激光器的研究成果,可以看出,国内外GTWave光纤激光器的发展极其迅猛,其功率扩展能力非常强、结构设计非常灵活,输出功率远高于其他光纤激光器;同时,对比分析了高功率GTWave光纤激光器的特点和优势,并对今后的研究进行了展望。     

CO2激光熔接型双包层光纤侧面抽运耦合器

为了把高功率的半导体激光器抽运光耦合入直径只有数百微米的双包层光纤内包层,以获得高的抽运功率,同时简化端面抛磨式熔接型侧面耦合器复杂的光纤处理工艺,提出了一种基于CO2激光熔接的双包层光纤侧面抽运耦合器的新方法,并进行了实验验证,介绍了试验装置和制作过程,制作了内包层直径为125μm非掺杂双包层光纤与105μm/125μm多模光纤的侧面耦合器,得到了82%的耦合效率测试结果。结果表明,所研制的熔接型侧面耦合器在侧面抽运的高功率双包层光纤激光器中具有很好的应用前景。     

高功率光纤激光器发展概况

高功率光纤激光器以其优越的性能和超值的价格,在光通信、印刷、打标、材料加工、医疗等领域有着广阔的应用,将会很大程度上替代传统激光器,并开辟一些新的激光应用领域,扩大激光产业的规模.概述国内外高功率光纤激光器的发展历史与现状.展望了高功率光纤激光器的发展前景.     

Strongly pumped fiber lasers

Strongly pumped fiber lasers are analyzed, based on a rate equation model. Examples include Nd³⁺-doped and Yb³⁺ -doped fiber lasers, with distributed Bragg reflector mirrors at either end. Approximate analytical and quasi-analytical expressions are shown to be in excellent agreement with the exact numerical solution of the rate equations, and both agree well with recently published experimental data     

光纤激光器的相干输出

研究了两路光纤激光的相位锁定和相干输出, 用融锥光纤耦合器实现了两路高掺铒光纤激光之间的相互耦合。提出了在激光器高反射率前腔镜的前面加融锥光纤耦合器的方法构成简单的共振腔, 从而实现两路光纤激光的相干叠加。开展了基于融锥光纤耦合器互注入锁相的两路光纤激光器的相干合成实验, 成功实现了两路光纤激光器的注入锁定, 观察到了波长锁定（中心波长稳定在1549.8 nm, 线宽为0.08 nm）、远场干涉条纹和线宽压缩现象。分析了单个激光器和激光器阵列的斜率效率, 当反射率为70%, 抽运功率均为145 mW时, 获得最大合成功率为127 mW。     

1.064- and 1.32-µm Nd:YAG single crystal fiber lasers

We report the development of CW 1.06- and 1.32-μm fiber lasers made of short sections of Nd:YAG single crystal fibers optically end-pumped either with an Argon-ion laser (lambda = 0.5145mum) or a single laser diode (lambda = 0.817mum). High conversion efficiencies, a few milliwatt thresholds and 10-20 mW output powers are reported, as well as a good coupling efficiency to a standard single-mode fiber. Loss mechanisms and means of reduction are also investigated for a variety of fiber lasers in either guided or unguided configurations.     

激光雷达用高性能光纤激光器

系统研究了窄线宽低噪声单频连续光纤激光器、高能量纳秒长脉冲单频光纤激光器以及高峰值功率纳秒短脉冲光纤激光器三类高性能光纤激光器:实现了工作于1、1.5及2 m波段的单频连续光纤激光器,典型光谱线宽小于3 kHz,强度噪声接近于散粒噪声极限;实现了高能量单频光纤激光器,脉冲能量超过200 J,重复频率20 kHz,脉冲宽度100~500 ns,激光波长位于1.5 m波段;实现了高峰值功率纳秒短脉冲光纤激光器,峰值功率超过700 kW,重复频率10 kHz,脉冲宽度3 ns;同时还实现了高重频高峰值功率纳秒短脉冲光纤激光器,峰值功率超过200 W,重复频率3 MHz,脉冲宽度1~5 ns。文中阐述了以上几类高性能光纤激光器在激光雷达探测系统中的应用前景。     

Raman fiber lasers for optical communication application

We review the principle and characteristics of cascaded Raman fiber lasers in their telecommunication applications. The fundamentals of Raman fiber lasers are described, such as pumping scheme, fiber type and reflectors. We explain simple equations forcw laser operation as well as a possible way to calculate spectral width. We investigate the common issues in the use of Raman fiber lasers: theoretical optimization, control of the linewidth, suppression level of the other Stokes orders and relative intensity noise. Finally the more complex multiple-wavelength Raman fiber lasers are reviewed.