共查询到20条相似文献,搜索用时 62 毫秒
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为了实现低阈值光纤激光器的频率稳定输出,设计了环形腔光纤激光器,以光纤光栅作为波长选择元件,在未泵浦光纤饱和吸收体和其锥形化结构的协同作用下实现激光纵模选择,获得了短光纤饱和吸收体长度下的单纵模激光稳定输出。介绍了未泵浦光纤饱和吸收体选频原理和锥形结构滤波原理,实验研究了不同光纤饱和吸收体长度下激光纵模特性和波长稳定性,以及锥形化光纤饱和吸收体的激光输出特性。实验表明,引入锥形化结构的饱和吸收体后,激光器能够稳定输出1545 nm波长的单纵模激光,并有效降低光纤激光器阈值至7.58 mW,采用延迟自外差方法测得该光纤激光器的线宽小于8 kHz。 相似文献
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为了研究基于半导体可饱和吸收镜的被动锁模光纤激光器的输出特性,采用1480nm的半导体激光器作为抽运源,利用掺铒光纤作为增益介质,以及光纤环行器、偏振控制器、波分复用器和耦合器等构成了环形腔结构的被动锁模光纤激光器。实验中获得了峰值波长1586nm、光谱宽度4.8nm、重复频率11.2MHz、最大平均输出功率8.4mW的稳定锁模激光脉冲输出。结果表明,调整光纤偏振控制器会使光纤激光器输出脉冲的时域波形略微发生变化,在实际应用中需要注意偏振态变化对锁模光纤激光器输出脉冲时域特性的影响。这一结果对于半导体可饱和吸收镜在被动锁模光纤激光器中的应用及其特性具有一定帮助。 相似文献
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Pulsing behavior of a three-level laser with saturable absorber 总被引:5,自引:0,他引:5
A numerical study of a three-level laser model that includes a saturable absorber is presented. The theory models the laser as a lumped element. This assumption is valid as long as the laser pulses are much longer than the cavity. The model is intended to be somewhat representative of an erbium-doped fiber laser without trying to mimic the operating parameters of such a laser too closely. As expected, the presence of the saturable absorber causes the laser to be unstable under certain operating conditions. The question of stability is explored by examining small perturbations of the steady-state solutions of the rate equations. It is found that the predictions of this stability analysis are in excellent agreement with the behavior of the solutions of the full time-dependent rate equations. It is also found that under certain conditions the laser may pass from pulsed to stable operation simply by raising the pump power 相似文献
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You-Jian Song Ming-Lie Hu Chang-Lei Wang Zhen Tian Qi-Rong Xing Lu Chai Ching-Yue Wang 《Photonics Technology Letters, IEEE》2008,20(13):1088-1090
A high pulse energy passively mode-locking fiber laser operating in the soliton-like regime is demonstrated. The laser is based on a linear cavity design. A segment of Yb-doped single-polarization large-mode-area photonic crystal fiber serves as the gain medium, and the self-starting mode-locking is achieved by a high contrast semiconductor saturable absorber mirror. The laser directly generates 600-fs pulses with 900 mW of average power at a repetition rate of 47.3 MHz, corresponding to a single pulse energy of 19 nJ. Furthermore, this fiber laser is directly used for pumping ZnTe to generate broadband terahertz radiation, resulting in a compact terahertz source. 相似文献
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An advanced design of a diode-pumped passively Q-switched erbium fiber laser with a Co/sup 2+/:ZnSe crystal as a saturable absorber is reported. The laser giant-pulse operation is obtained with threshold of 8.3 mW, repetition rate of pulses of 235 kHz, and pulse energy, peak power, and duration of 15 nJ, 43 mW, and 350 ns, respectively. The self-mode-locking effect in the passively Q-switched fiber laser has been observed experimentally for the first time. 相似文献
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根据非线性薛定谔方程建立了基于可饱和吸收体被动锁模掺Er3+氟化物光纤激光器的理论模型,研究了中红外超短脉冲在掺Er3+氟化物光纤激光器中形成的物理机制,数值模拟了被动锁模掺Er3+氟化物光纤激光器中中红外超短脉冲的演化过程,重点分析了掺Er3+增益光纤长度,可饱和吸收体不饱和损耗对被动锁模掺Er3+氟化物光纤激光器产生中红外超短脉冲的影响,并给出了参数设置范围。研究发现:当小信号增益系数、可饱和吸收体不饱和损耗、腔内净色散量为一定值,掺Er3+氟化物光纤长度在一定范围时,才会出现稳定的锁模脉冲,且随着掺Er3+氟化物光纤长度增加脉冲宽度变窄、光谱变宽、峰值功率增高;当掺Er3+氟化物光纤长度、腔内净色散量、小信号增益系数为一定值时,可饱和吸收体不饱和损耗在一定的范围时可以得到稳定的锁模脉冲,且随着可饱和吸收体不饱和损耗的增加脉冲宽度变窄,光谱先变宽后变窄变化范围不大,峰值功率增加。 相似文献
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基于单壁碳纳米管可饱和吸收体的被动锁模光纤激光器研究 总被引:3,自引:1,他引:2
基于单壁碳纳米管(SWCNTs)作为光学可饱和吸收体(SA)的恢复时间快(<1ps)、饱和光强低、锁模自启动、工作光谱范围宽且制备方法简单、成本低、化学稳定性好、易与光纤兼容等优点,利用SWCNTs-SA实现了稳定脉冲序列输出的实验结果。利用聚甲基丙烯酸甲酯(PMMA)易成膜且机械性能良好的特点,将SWCNTs与PMMA一起分散在二氯化苯(DCB)溶液中,运用光学诱导作用将SWCNTs吸附在单模光纤(SMF)端面,并加热固化成膜。在光纤激光器环形腔结构中引入SWCNT/PMMA薄膜作为SA,获得了具有稳定的重复频率为8.366MHz的基频锁模脉冲序列,其中心波长在1 562nm,脉冲宽度为1.2ps。 相似文献
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Herda R. Kivist S. Okhotnikov O.G. Kosolapov A.F. Levchenko A.E. Semjonov S.L. Dianov E.M. 《Photonics Technology Letters, IEEE》2008,20(3):217-219
We exploit the anomalous dispersion generated by an index-guided photonic crystal fiber (PCF) for dispersion compensation in an ytterbium fiber laser passively mode-locked with a semiconductor saturable absorber. A PCF, reasonably compatible with standard fiber, and a Faraday rotator in the cavity allow for robust all-fiber subpicosecond operation at 1 m, insensitive to environmental disturbance. 相似文献
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M. Laroche H. Gilles S. Girard N. Passilly K. Ait-Ameur 《Photonics Technology Letters, IEEE》2006,18(6):764-766
We explored efficient nanosecond pulse generation in a passively Q-switched cladding-pumped Yb-doped fiber laser by use of an external-cavity configuration containing a Cr/sup 4+/:YAG saturable absorber crystal. By exploiting passive Q-switched regime and stimulated Brillouin scattering, pulses of durations as short as 2.7 ns, corresponding to a peak power of /spl sim/9 kW, have been achieved. The laser was tunable over 70 nm and green output power generation was obtained by external frequency doubling in a KTP crystal. 相似文献
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We demonstrate a fiber laser that is passively mode locked by a semiconductor saturable absorber and stabilized by the amplitude modulation. The synchronization of a dropout-free harmonic mode locking to an external clock was obtained with the pulse characteristics solely determined by the saturable absorber action, and not by the applied amplitude modulation. The results show that significant suppression of undesired harmonics can be obtained with small perturbations provided by the amplitude modulation 相似文献
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高功率被动锁模2.0μm掺铥飞秒脉冲光纤激光器 总被引:3,自引:1,他引:2
报道了高功率半导体可饱和吸收镜被动锁模的2.0μm掺铥飞秒脉冲光纤激光器的实验结果。该光纤激光器利用半导体可饱和吸收镜与宽带全反射镜来构成线型法布里-珀罗腔,自制的1550nm连续掺铒光纤激光器作为激光抽运源。当抽运功率为312mW时,开始得到稳定的重复频率为53MHz的锁模激光脉冲串。当抽运功率增加到472mW时,得到的最大平均输出功率为50mW,相应的最高单脉冲能量为0.94nJ;此时测得锁模激光脉冲的宽度为907fs,激光的中心波长为1939.5nm,3dB光谱带宽为4.6nm。 相似文献
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Optical gain control (OGC) can be used to lock the inversion of an erbium-doped fiber amplifier (EDFA), assuming that the gain medium is homogeneous. However, EDF's exhibit certain degrees of spectral hole burning. As a result, when the OGC laser power and the spectral-hole depth at the laser wavelength change, the inversion of the EDFA changes accordingly with a fixed OGC cavity loss. In this work, a saturable absorber is placed in the OGC laser cavity to adjust the cavity loss dynamically and compensate the gain tilt caused by the OGC laser spectral hole burning. It is demonstrated that the steady state gain variation of a surviving channel in an optically gain controlled EDFA is improved from 1.3 dB (with a fixed loss) to 0.4 dB (with a saturable absorber in the cavity). The transient response of this gain control scheme is also discussed 相似文献
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A novel all-fibre saturable absorber based on the interaction between the evanescent field of a tapered single-mode fibre and a surrounding solution of a laser dye is described. Results are presented which demonstrate saturable absorption at pump powers of only tens of milliwatts.<> 相似文献
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Yong-Won Song S.Y. Set S. Yamashita C.S. Goh T. Kotake 《Photonics Technology Letters, IEEE》2005,17(8):1623-1625
For the first time, we demonstrate a novel passively mode-locked fiber laser operating at 1300 nm using purified single-walled carbon nanotubes (CNTs) as a saturable absorber. The saturable absorber incorporates diameter-controlled CNTs with peak absorption /spl sim/1300 nm, guaranteeing mode-locking over the same wavelength region. The ring laser uses praseodymium-doped fiber as a gain medium. The pulse repetition rate is 3.18 MHz, and the spectral half-width is 0.15 nm. Dual-wavelength mode-locking is also demonstrated with a channel spacing of 1.1 nm. 相似文献