碲化铋倏逝场锁模器件的超快光纤激光器

为使光纤激光器在被动谐波锁模状态下实现锁模脉冲高重复频率输出,本文通过激光沉积法制备了一种基于非线性拓扑绝缘体材料碲化铋与侧面抛磨光纤相结合的可饱和吸收体锁模器件,该器件调制深度、非饱和损耗、饱和强度分别为23.96%、37.77%、31.5 MW/cm2。将其应用在掺铒光纤激光器中,通过对整个腔内色散参数的调整,以及利用材料自身良好的非线性可饱和吸收能力,成功实现了锁模自启动,其中心波长为1 555.67 nm,脉冲宽度为487 fs,重复频率为47.87 MHz,信噪比为58 dB。当泵浦功率超过150 mW时出现锁模脉冲的谐波分裂,持续对泵浦功率进行微调,增加直至最高功率250 mW时,出现了11阶谐波锁模脉冲,重复频率最高达到528 MHz,此时的信噪比为41.5 dB。本文结果证明利用侧面抛磨光纤结构的倏逝场,能够辅助材料提升一定的激光抗损伤能力,便于其在基本锁模状态下进一步实现被动谐波锁模,满足锁模脉冲高重频的产生及探究,对材料在高重频超快光纤激光器中的应用具有重要意义。     

高重复频率全光纤被动锁模掺铒光纤激光器

报道了一种高重复频率全光纤非线性偏振旋转锁模掺铒光纤激光器, 获得了重复频率217 MHz的锁模脉冲输出. 该激光器使用一个偏振相关隔离器和一个偏振控制器即可获得稳定的锁模脉冲输出, 结构简单, 系统稳定. 激光器锁模脉冲的脉冲宽度为69 fs, 3 dB光谱宽度为56 nm, 射频频谱信噪比为76 dB.     

全光纤色散腔掺铒光纤激光器

报道用９７１ｎｍ半导体激光器泵浦的掺铒光纤激光器的一些实验研究结果。演示了由光纤环反射器和光纤光栅构成的全光纤色散掺铒光纤激光器，在１．５５μｍ波段获得了线宽小于０．０５ｎｍ的激光输出。     

基于单壁碳纳米管的双向锁模掺铒光纤激光器

设计了一种没有隔离器的单壁碳纳米管双向被动锁模光纤孤子激光器.该光纤激光器由波分复用器、掺铒光纤、光耦合器、碳纳米管、单模光纤和偏振控制器组成.在环形腔的两个相反方向上,同时实现基于碳纳米管饱和吸收体的被动锁模,得到两个反向稳定脉冲序列.调节激光腔中的偏振控制器以及泵浦激光源,分析该实验装置在不同泵浦功率下的输出特性.结果表明,中心波长变化范围为1 558~1 560nm,顺时针脉冲宽度变化范围为854~959ps,逆时针脉冲宽度变化范围为247~624ps.此外,泵浦功率较大时,逆时针方向上脉冲序列分裂.     

自启动被动锁模掺铒光纤激光器的研究

在非线性光纤环形镜非线性开关效应和块状半导体波导饱和吸收效应的共同作用下，实现了掺铒光纤激光器的自启动被动锁模，获得了十分稳定的锁模脉冲序列，观察到高次谐频锁模脉冲输出。分析了非线性光纤环形镜的非线性开关反射特性。     

掺铒光纤激光器输出特性的解析研究

从描述掺铒光纤激光器的速率方程组出发，对９８０ｎｍ和１４８０ｎｍ波段泵浦下掺铒光纤激光器的输出特性进行了解析研究，得到了这两个波段泵浦下下输出功率，斜效率等重要参烽的隐式或显示解析表达式。     

超长腔碳纳米管锁模多波长掺镱光纤激光器

报道了一种超长腔碳纳米管锁模多波长掺镱光纤激光器, 光纤激光器的总长度为1021.2 m. 实验得到了噪声型孤子和孤子雨两种类型的多波长锁模脉冲, 重复频率均为199.8 kHz. 孤子雨具有更高的输出功率和单脉冲能量, 分别为40.3 mW和201.5 nJ, 对应的脉冲宽度为102.5 ns.     

可调谐锁模脉冲环形腔掺铒光纤激光器

报道了一种结构简单、波长稳定可调的被动锁模环形腔掺铒光纤激光器.利用非线性偏振旋转效应作为等效可饱和吸收体实现自起振被动锁模,通过使用光纤偏振控制器和偏振相关光隔离器作为波长调谐器件,在输出端使用输出耦合器为工作波长在1550±50 nm的宽带耦合器,实现了光纤激光器的输出锁模脉冲激光中心波长较宽范围可调谐.实验上获得了低阈值自起振,重复频率为10.23 MHz,中心波长在1548.64～1600.24 nm内连续可调,边模抑制比大于44 dB的超短脉冲输出.     

基于非线性光纤环形镜被动锁模掺铒光纤激光器

研究了一种基于非线性光纤环形镜"8"字形谐振腔结构的波长可调谐被动锁模掺铒光纤激光器,该激光器通过将偏振控制器加在耦合比为30/70的2×2光纤耦合器首尾相连的环内,在整个谐振腔的右端搭建了一个Sagnac环形滤波器.当泵浦功率为270 mW时,锁模光纤激光器输出了中心波长为1555.7 nm的传统孤子,其光谱的3-d...     

快速与慢速饱和吸收体被动锁模掺铒光纤激光器的理论分析

利用半导体饱和吸收波导作为慢速饱和吸收体与非线性快速饱和吸收体相结合，建立了共同被动锁模掺铒光纤激光器的理论模型-分析了半导体饱和吸收波导、光纤自相位调制和自振幅调制对锁模脉冲宽度和脉冲啁啾的影响- 关键词：     

Zinc-oxide/PDMS-clad tapered fiber saturable absorber for passively mode-locked erbium-doped fiber laser

We propose and demonstrate a passively mode-locked erbium-doped fiber laser(EDFL) based on zincoxide/polydimethylsiloxane(Zn O/PDMS) saturable absorber(SA) that evanescently interacts with the light on a tapered fiber. The Zn O/PDMS composite is coated on the whole surface of the tapered fiber to guarantee the maximum efficiency of the SA device, with a measured insertion loss of 0.87 d B and a modulation depth of 6.4%. The proposed laser can generate soliton mode-locking operation at a threshold power of 33.07 m W. The generated output pulse yields a repetition rate and pulse width of 9.77 MHz and 1.03 ps, respectively. These results indicate that the proposed Zn O/PDMS-clad tapered fiber could be useful as an efficient, compatible, and low-cost SA device for ultrafast laser applications.     

石墨烯可调谐被动调Q掺铒光纤激光器

基于光学沉积方法,制备了石墨烯可饱和吸收体,并利用此可饱和吸收体搭建了环形腔结构的被动调Q掺铒光纤激光器,实现了稳定的调Q激光脉冲输出,其重复频率为5.1~14.2 kHz,最窄激光脉冲宽度为8 s,最大平均功率为162.3 W,且通过调节偏振控制器,中心波长在1556~1558 nm可调。     

碳纳米管锁模双包层光纤激光器的实验研究

本文采用双包层掺镱光纤作为增益介质,用单壁碳纳米管作为饱和吸收体,获得最高输出功率为336 mW的锁模脉冲激光.用飞秒激光诱导水击穿法直接在单模光纤上制备出D形区,通过在D形光纤上滴涂单壁碳纳米管溶液,成功制备出碳纳米管饱和吸收体,并对其饱和吸收特性进行测试,发现其调制深度为27％.利用该饱和吸收体作为锁模器件,制备出具有环形腔结构的锁模光纤激光器.当抽运功率为4W时,获得了脉宽为93.8 fs,中心波长为1083.8 nm,3 dB谱宽为8.6 nm,重复频率为5.59 MHz,平均功率为336 mW的飞秒脉冲激光输出.     

Passively mode-locked erbium-doped fiber laser via a D-shape-fiber-based MoS_2 saturable absorber with a very low nonsaturable loss

We report on the generation of conventional and dissipative solitons in erbium-doped fiber lasers by the evanescent field interaction between the propagating light and a multilayer molybdenum disulfide(MoS_2) thin film. The MoS_2 film is fabricated by depositing the MoS_2 water–ethanol mixture on a D-shape-fiber(DF) repetitively. The measured nonsaturable loss, saturable optical intensity, and the modulation depth of this device are 13.3%, 110 MW/cm~2, and 3.4% respectively.Owing to the very low nonsaturable loss, the laser threshold of conventional soliton is as low as 4.8 mW. The further increase of net cavity dispersion to normal regime, stable dissipation soliton pulse trains with a spectral bandwidth of 11.7 nm and pulse duration of 116 ps are successfully generated. Our experiment demonstrates that the MoS_2-DF device can indeed be used as a high performance saturable absorber for further applications in ultrafast photonics.     

氧化石墨烯被动调Q掺铒光纤激光器

报道了基于氧化石墨烯的被动调Q掺铒光纤激光器。激光器采用环形腔结构,调Q器件为自制的氧化石墨烯可饱和吸收镜。泵浦功率在81~505 mW范围内时,得到了重复频率68~124 kHz的稳定的调Q脉冲输出,脉宽为0.47~1.60 s。由于泵浦功率限制,激光器最大输出功率为10 mW, 相应单脉冲能量为80.6 nJ。此种基于氧化石墨烯可饱和吸收体的被动调Q光纤激光器体积小、成本低廉、结构简单、稳定性高、光束质量高,具有广阔的应用前景。     

基于石墨烯可饱和吸收体的纳秒锁模掺铥光纤激光器

报道了一种基于石墨烯可饱和吸收体的纳秒锁模掺铥光纤激光器.该激光器采用环形腔结构,利用自制的三层石墨烯薄膜作为可饱和吸收体实现锁模.同时在腔内插入一个窄带光纤光栅,约束腔内起振的纵模数,适当调节抽运功率和偏振控制器的角度,得到了重复频率为3.8 MHz、脉宽在3.8—94.3 ns之间灵活可调的2μm纳秒锁模脉冲输出,整个脉宽调节范围超过90 ns.此外,由于获得的兆赫兹纳秒锁模脉冲时间带宽积在49—1119范围内,即存在强烈的啁啾,因而可作为2μm波段啁啾脉冲放大系统中的种子源使用.     

Low-repetition-rate,all-polarization-maintaining Yb-doped fiber laser mode-locked by a semiconductor saturable absorber

A low-repetition-rate, all-polarization-maintaining(PM)-fiber sub-nanosecond oscillator is presented, which is simple and low-cost, composed of standard components. The ring cavity is elongated by 114-m-long standard PM fiber, and passively mode-locked by a fiber pigtailed semiconductor saturable absorber. Linearly polarized pulses with 1.66 MHz repetition rate and 22 dB polarization extinction ratio are generated at a wavelength of 1030 nm, which is determined by an intracavity filter. In addition, to demonstrate that the oscillator is a good seed for high energy pulse generation, an all-fiber master oscillator power amplifier is built and amplified pulses with energy about 2 μJ are obtained.     

Flexible pulses from carbon nanotubes mode-locked fiber laser

We demonstrate a flexible erbium-doped pulsed fiber laser which achieves the wavelength and pulse width tuning by adjusting an intracavity filter. The intracavity filter is flexible to achieve any of the different wavelengths and bandwidths in the tuning range. The wavelength and width of pulse can be tuned in a range of ~ 20 nm and from ~0.8 ps to 87 ps,respectively. The flexible pulsed fiber laser can be accurately controlled, which is insensitive to environmental disturbance.     

Sequential generation of self-starting diverse operations in all-fiber laser based on thulium-doped fiber saturable absorber

Self-starting Q-switching, Q-switched mode-locking and mode-locking operation modes are achieved sequentially in an all-fiber erbium-doped fiber laser with thulium-doped fiber saturable absorber for the first time. The central wavelengths of Q-switching, Q-switched mode-locking and mode-locking operation modes are 1569.7 nm, 1570.9 nm, and 1572 nm, respectively. The mode-locking operation of the proposed fiber laser generates stable dark soliton with a repetition rate of 0.99 MHz and signal-to-noise ratio of 65 dB. The results validate the capability of generating soliton pulse by doped fiber saturable absorber. Furthermore, the proposed fiber laser is beneficial to the applications of optical communication and signal processing system.