激光二极管侧面抽运Nd∶YAG锁模激光器的研究

利用谐振腔的稳定条件对激光二极管侧面抽运的 Nd∶YAG锁模直腔的稳区特性和谐振腔内的光斑分布进行了分析。根据对腔参量的分析,选取合适的腔参量设计了一个简单的侧面抽运直腔,该谐振腔腔形简单,没有像散,振荡光模式好,有利于激光器的锁模运转。实验中采用国内自行研制的半导体可饱和吸收镜,实现了激光二极管侧面抽运半导体可饱和吸收镜锁模Nd∶YAG激光器的连续锁模运转,平均输出功率为 2 W,锁模脉冲宽度为10 ps,重复频率为100 MHz。结合实验结果进一步讨论了半导体可饱和吸收镜的一些参量如饱和恢复时间、调制深度等对实现稳定连续锁模的影响。     

Graphene Saturable Absorber Mirror for Mode-Locked Orange Pulse Laser

Journal of Russian Laser Research - We demonstrate a passively-mode-locked Pr3+: LuLiF4 laser operated at the 604 nm orange wave-length, using monolayer graphene as a saturable absorber. The...     

激光二极管侧面抽运Nd:YAG锁模激光器的研究

利用谐振腔的稳定条件对激光二极管侧面抽运的Nd：YAG锁模直腔的稳区特性和谐振腔内的光斑分布进行了分析。根据对腔参量的分析，选取合适的腔参量设计了一个简单的侧面抽运直腔，该谐振腔腔形简单，没有像散，振荡光模式好，有利于激光器的锁模运转。实验中采用国内自行研制的半导体可饱和吸收镜，实现了激光二极管侧面抽运半导体可饱和吸收镜锁模Nd：YAG激光器的连续锁模运转，平均输出功率为2W，锁模脉冲宽度为10ps，重复频率为100MHz。结合实验结果进一步讨论了半导体可饱和吸收镜的一些参量如饱和恢复时间、调制深度等对实现稳定连续锁模的影响。     

40 GHz Mode-Locked Semiconductor Lasers: Theory, Simulations and Experiment

We study both theoretically and experimentally typical operation regimes of 40 GHz monolithic mode-locked lasers. The underlying Traveling Wave Equation model reveals quantitative agreement for characteristics of the fundamental mode-locking as pulse width and repetition frequency tuning, as well as qualitative agreement with the experiments for other dynamic regimes. Especially the appearance of stable harmonic mode-locking at 80 GHz has been predicted theoretically and confirmed by measurements. Furthermore, we derive and apply a simplified Delay-Differential-Equation model which guides us to a qualitative analysis of bifurcations responsible for the appearance and the breakup of different mode-locking regimes. Higher harmonics of mode-locking are predicted by this model as well.     

直接调制半导体激光器的脉冲驱动电路研究

研制了一种应用于直接调制半导体激光器的脉冲驱动电路.根据直接数字频率合成原理,利用现场可编程逻辑阵列产生频率可调方波去触发雪崩晶体管,以及雪崩晶体管的雪崩效应产生频率可调脉宽固定在3 ns的主体脉冲.该脉冲经过衰减器衰减得到合时的脉冲幅度.输出脉冲最高频率可到100 kHz,其输出电压幅度为9 V.     

高能量,长锁模脉冲序列的Nd：YLF激光器研究

首次利用ＧａＡｓ光电导开关构成的反馈回路，正、负反馈联合作用，动态控制Ｎｄ：ＹＬＦ被动锁模激光器腔内的Ｑ值，得到高能量、长序列的稳态锁模脉冲。稳态单脉冲的脉宽为４ｐｓ，能量为９μＪ，脉冲序列长１６μｓ，能量为２．５ｍＪ。     

Wavelength-Tunable Rectangular Pulse Dissipative Soliton Operation of an Erbium-Doped Mode-Locked Fiber Laser

The wavelength-tunable rectangular pulse dissipative soliton （DS） is experimentally demonstrated, for the first time to the best of our knowledge, in an erbium-doped figure-of-eight fiber laser based on the nonlinear amplifying loop mirror mode-locked technique. The proposed rectangular pulse DS fiber laser can operate in the wavelength- tunable mode-locked state from 1573.5nm to 159d.6 nm with the rotation of the polarization controllers. The achieved output wavelengths are 1573.5nm, 1576.3nm, 1586.8nm, 1590.4nm and 1594.6nm, respectively. The pulse widths of the rectangular pulse can also be tuned from ~8ns to ~24ns by adjusting the pump power. The fundamental repetition rate of the rectangular pulse DS is 1.154 MHz and the output power is 6.1d m W （at 1594.6 nm）.     

Wavelength-Tunable Rectangular Pulses Generated from All-Fiber Mode-Locked Laser Based on Semiconductor Saturable Absorber Mirror

The wavelength-tunable rectangular mode-locking operation is demonstrated in an all-fiber laser based on semiconductor saturable absorber mirror.As the dissipative soiiton resonance signature,the puJse duration varies from 580 ps to 2.1 ns as a function of the increasing pump power.Correspondingly,the maximum pulse energy is9.11 nJ.Moreover,it is found that the wavelength tunable operation with a range of approximately 10 nm could be obtained by properly adjusting the polarization controllers.The characteristics of the rectangular pulses at different wavelengths are similar to each other.The demonstration of the wavelength tunable rectangular pulses would be beneficial to some applications for many fields such as spectroscopy and sensing research.     

激光二极管泵浦的准连续运转飞秒Cr:LiSAF激光器

报道国内第一台用６７０ｎｍ激光二极管泵浦的准连续锁模运转的Ｃｒ：ＬｉＳＡＦ激光器。对于连续运转,泵浦阈值功率２４０ｍＷ,当吸收功率为３６８ｍＷ的输出,输出波长８５０ｎｍ,斜效率为３．５％。在准连续运转（１００ＨＺ,占空比１／５时）,泵清阈值功率４５ｍＷ,斜效率为９．８％,用染料作为锁模妄动介质,实现了准连续锁模运转,光脉冲输出的中心波长为８５０ｎｍ。     

Fiber Optic Raman Distributed Temperature Sensor Based on an Ultrashort Pulse Mode-Locked Fiber Laser

Optics and Spectroscopy - The testing of an all-fiber erbium ultrashort pulsed laser in a distributed fiber temperature sensor as a source of probing pulses has been performed. Among the prospects...     

High-Energy Rectangular Pulse Dissipative Soliton Generation in a Long-Cavity Sigma-Shaped Configuration Mode-Locked Fiber Laser

The high-energy rectangular pulse dissipative soliton （DS） is achieved in a long-cavity sigma-shaped configuration erbium-doped fiber laser. A long fiber is inserted in the linear arm of the sigma-shaped configuration to extend the resonator length twice, which effectively improves the pulse energy. The nonlinear polarization rotation technique is employed to realize the mode-locked state. Stable rectangular pulses with pulse energy of 421.22 nJ are obtained at the pump power of 620mW. To the best of our knowledge, this high pulse energy is a new record of the rectangular pulse mode-locked DS fiber lasers.     

基于注入锁模激光器的40 Gb/s全光时钟提取

利用注入锁模光纤激光器进行时钟提取实验,成功地从40Gb／s伪随机码信号中提取出了40GHz时钟信号。实验中,在注入信号进入环形腔之前先通过一个马赫-曾德尔（M-z）干涉仪,提高了注入信号中时钟频谱分量的相对大小,从而有利于时钟信号的提取。首先从10Gb／s伪随机码信号中提取出波形很好的10GHz时钟信号,并在此基础上从复用后的40Gb／s伪随机码信号中提取出了40GHz时钟信号。     

一种新型可调谐锁模光纤激光器

利用法布里-珀罗腔的激光二极管作为调制器件，实现环形腔光纤激光器的主动锁模。并利用法布里-珀罗腔的激光二极管的多纵模特性，把激光二极管当作一梳状滤波器，通过偏振控制器来调整入射到激光二极管内光的偏振态，同时均衡腔内增益，得到波长大范围可调谐的锁模激光，其脉冲宽度约为48ps，脉冲重复速率2GHz。     

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。     

Raman-Assisted Passively Mode-Locked Fiber Laser

We propose and demonstrate a Raman-assisted passively mode-locked Yb-doped fiber laser in a normal dispersion regime. A section of highly nonlinear fiber is adopted to enhance the nonlinearity to extend the bandwidth of the gain spectrum by the stimulated Raman effect. The mode-locked fiber laser emits a broad spectral bandwidth of 64 nm at the-20 dB level and a highly stable pulse operation with a signal-to-noise ratio of 77 dB.     

电光腔倒空激光二极管抽运Nd:YAG锁模激光器

设计了一个简单的直腔。将电光腔倒空与激光二极管端面抽运Nd：YAG半导体可饱和吸收镜锁模激光器结合，实现了锁模脉冲的产生、放大和输出。在连续抽运功率5W的条件下。获得了脉冲宽度为11ps的锁模单脉冲输出和脉冲宽度为200ns的调Q脉冲输出，腔倒空单脉冲能量为30nJ，重复频率为10Hz。连续锁模运转时单个锁模脉冲的能量约为2nJ。利用腔倒空将单脉冲的能量提高了15倍左右。文章详细讨论了腔倒空脉冲及调Q脉冲的产生机理，并分析了加在电光晶体上的高压电脉冲以及偏振片的偏振度对腔倒空脉冲及调Q脉冲的影响。     

电光腔倒空激光二极管抽运Nd∶YAG锁模激光器

设计了一个简单的直腔,将电光腔倒空与激光二极管端面抽运Nd∶YAG半导体可饱和吸收镜锁模激光器结合,实现了锁模脉冲的产生、放大和输出。在连续抽运功率5 W的条件下,获得了脉冲宽度为11 ps的锁模单脉冲输出和脉冲宽度为200 ns的调Q脉冲输出,腔倒空单脉冲能量为30 nJ,重复频率为10 Hz。连续锁模运转时单个锁模脉冲的能量约为2 nJ,利用腔倒空将单脉冲的能量提高了15 倍左右。文章详细讨论了腔倒空脉冲及调Q脉冲的产生机理,并分析了加在电光晶体上的高压电脉冲以及偏振片的偏振度对腔倒空脉冲及调Q脉冲的影响。     

Short Terahertz Pulse Generation from a Dispersion Compensated Modelocked Semiconductor Laser

Dispersion compensation is vital for the generation of ultrashort and single cycle pulses from modelocked lasers across the electromagnetic spectrum. It is typically based on addition of an extra dispersive element to the laser cavity that introduces a chromatic dispersion opposite to that of the gain medium. To date, however, no dispersion compensation schemes have been successfully applied to terahertz (THz) quantum cascade lasers for short and stable pulse generation in the THz range. In this work, a monolithic on‐chip compensation scheme is realized for a modelocked QCL, permitting THz pulses to be considerably shortened from 16ps to 4ps. This is based on the realization of a small coupled cavity resonator that acts as an ‘off resonance’ Gires‐Tournois interferometer (GTI), permitting large THz spectral bandwidths to be compensated. This novel application of a GTI opens up a direct and simple route to sub‐picosecond and single cycle pulses in the THz range from a compact semiconductor source.     

Tunable and Switchable Narrow Bandwidth Semiconductor-Saturable Absorber Mirror Mode-Locked Yb-Doped Fiber Laser Delivering Different Pulse Widths

The wavelength-tunable and switchable narrow bandwidth mode-locking operation is demonstrated in an all fiber laser based on semiconductor-saturable absorber mirror(SESAM).Two narrow-band fiber Bragg gratings centered at 1029.9 nm and 1032 nm respectively with a polarization controller inserted between them are used to realize the wavelength switchable between 1029.9nm and 1032 nm.The laser delivers different pulse widths of 7.5ps for 1030 nm and 20 ps for 1032 nm.The maximum output power for both could reach ~6.5mW at single pulse operation.The output wavelength could be tuned to about 0.9nm intervals ranging from 1030.2nm to 1031.1 nm and from 1032.15 nm to 1033.7nm with the temperature change of the fiber Bragg grating,respectively.