共查询到20条相似文献,搜索用时 62 毫秒
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为了对掺Yb3+双包层光纤激光器的自脉冲行为进行系统的理论研究,采用数值模拟方法,对光子数密度和反转粒子数密度随时间及抽运功率的变化、阻尼系数与后腔镜的反射率和掺杂粒子浓度的关系,以及光纤本身固有振荡频率随后腔镜反射率的变化进行了理论分析.结果表明,随抽运功率的增加,振荡频率增加,振幅度减小;降低输出端的反馈和粒子的浓度可以抑制自脉冲现象.另外提出了抑制光纤激光器自脉冲的措施,为设计掺Yb3+双包层光纤激光器提供了理论依据. 相似文献
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超短脉冲掺Yb3+光纤激光器实验研究 总被引:3,自引:1,他引:3
报道了使用976nm半导体激光器作为抽运源。以掺Yb^3 光纤作增益介质构成环形腔激光器产生超短脉冲的实验研究。在腔体净群速度色散为正的掺Yb^3 光纤环形腔激光器中,采用非线性偏振旋转的相加脉冲锁模技术。通过调节偏振控制器的方向和减少腔内损耗,实现稳定的锁模运转。用示波器观察光纤激光器在时域的输出特性,在抽运光一定的情况下,随着光偏振状态的变化,光纤激光器锁模激光的变化呈现稳定和不稳定两个区域。在不稳定锁模区域,激光为不规则的脉冲。通过仔细调节光纤偏振控制器的位置,当光纤偏振控制器在某一适当位置时。激光器工作在稳定的锁模区域。获得最大功率为9.46mW,脉冲激光光谱宽度为10nm.脉冲的重复频率为15.4MHz。 相似文献
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PLZT电光陶瓷具有良好的透明性、高电光系数等特性,用来实现全光纤调Q开关具有很大的优势.分析了PLZT全光纤调Q开关的原理,测量了调Q开关的时间波形,研究了基于PLZT开关的全光纤单模环形调Q掺Yb3 光纤激光器.抽运光功率为180 mW,莆复频率为1 kHz时,得到峰值功率25.6 W,脉冲宽度80 ns,光谱宽度1 nm,脉冲能量2.0 μJ的调Q脉冲.此外,分别研究了抽运功率和重复频率对脉冲峰值功率和脉冲宽度的影响,结果表明,同一重复频率情形下,随着抽运功率的升高,峰值功率增大,脉冲宽度降低;同一抽运功率水平下,随着重复频率的增大,脉冲的峰值功率减小,脉冲宽度增大. 相似文献
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光纤激光器以其独特的优势得到快速发展,其应用范围已经扩展到工业加工、国防军事、医疗等领域。综述了连续、脉冲掺Yb3+双包层光纤激光器的国内外研究进展,介绍了利用能承受高功率的合束器、光纤光栅的全光纤激光器,利用种子光主振荡光纤放大技术产生高光束质量、高平均功率、高峰值功率的脉冲光纤激光器。分析了影响光纤激光器功率提高的因素,如光纤的损伤、非线性性效应、热效应。最后,对掺Yb3+双包层光纤激光器的发展前景进行了展望。 相似文献
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Wadsworth W.J. Knight J.C. Reeves W.H. Russell P.S.J. Arriaga J. 《Electronics letters》2000,36(17):1452-1454
An ytterbium doped core has been incorporated into a photonic crystal fibre (PCF) with anomalous group velocity dispersion at all wavelengths longer than 730 nm. Laser action is observed for the first time in such a fibre. This demonstration of lasing in PCF is a vital step towards realising the huge potential of PCF for fibre laser applications 相似文献
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The effective index of the cladding fundamental space-filling mode in photonic crystal fiber (PCF) is simulated by the effective index method. The variation of the effective index with the structure parameters of the fiber is achieved. For the first time, the relations of the V parameter of Yb3+-doped PCF with the refractive index of core and the structure parameters of the fiber are provided. the single-mode characteristics of large-core Yb3+-doped photonic crystal fibers with 7 and 19 missing air holes in the core are analyzed. The large-core single-mode Yb3+-doped photonic crystal fibers with core diameters of 50 μm, 100 μm and 150 μm are designed. The results provide theory instruction for the design and fabrication of fiber. 相似文献
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《Photonics Technology Letters, IEEE》1994,6(3):369-371
We demonstrate a simple method to produce high-energy pulses with peak powers up to 100 times their average power and with duration on the order of 1 μs using the synchronization of relaxation oscillations by drive current modulation of the intracavity pump laser diode. The forced sustained relaxation oscillations are shown to depend on wavelength, and the frequency locking curve exhibits a strong asymmetry with hysteresis behavior 相似文献
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Short high-concentration Yb3+-sensitized Er3+-doped fiber amplifiers are modeled and numerically investigated in the small-signal domain. Concentration quenching is included with a term quadratic in the concentration of excited Er3+ . We find that for fibers shorter than 1 m, the small-signal gain can be larger for sensitized fibers than for non-sensitized ones (31 dB gain vs. 22 dB at 5 cm). Without concentration quenching (e.g. for long fibers), Yb3+-free amplifiers have a higher small-signal gain. The achievable gain of the sensitized amplifier is independent of the pump laser wavelength, if the Yb-concentration is correspondingly optimized. However, restrictions on allowable Yb-concentrations imply that for a specific pump wavelength, a finite range of amplifiers lengths is suitable 相似文献
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A new type of high-power broadband superfluorescent source of Yb^3+ -doped double-cladding photonic crystal fiber is reported experimentally, which is pumped at 976 nm by a high-power laser diode with the end-coupling method. We have obtained a smooth broadband output of superfluorescence The maximum output power is 1.649 W with a slope efficiency of 56.7%. The 3 dB bandwidth is 22.4 nm To the best of our knowledge, this is the first report about SFS with such high output power of 1.649 W. 相似文献
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We present a Pr3+-doped silica-based fiber laser mode-locked by using a linear external cavity with a vibrating mirror. Stable laser pulses with a FWHM of less than 44 ps, peak power greater than 9 W, and repetition rate up to 100 MHz are obtained. The pulse width versus cavity mismatch ΔL and pump power have been investigated. With a short piece of nonlinear fiber included in the external cavity, laser pulses of 45 ps have been measured 相似文献
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Lester C. Bjarklev A. Rasmussen T. Dinesen P.G. 《Lightwave Technology, Journal of》1995,13(5):740-743
A model for Yb3+-sensitized Er3+-doped silica waveguide amplifiers is described and numerically investigated in the small-signal regime. The amplified spontaneous emission in the ytterbium-band and the quenching process between excited erbium ions are included in the model. For pump wavelengths between 860 and 995 nm, the amplified spontaneous emission in the ytterbium-band is found to reduce both the gain and the optimum length of the amplifier significantly. The achievable gain of the Yb3+-sensitized amplifier is found to be higher than in an Er3+-doped silica waveguide without Yb 3+ (18 dB versus 9 dB for a pump power of 100 mW). However, it is important to optimize the Yb-concentration according to the choice of pump wavelength 相似文献
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An Er3+-doped fiber ring laser with unidirectional operation without optical isolator has been investigated for different cavity conditions. The fiber ring laser cavity is built in such a way that the optical fields propagating in the two directions suffer different losses. As a consequence, the laser oscillation appears in a quasi-unidirectional form. By incorporating a fiber pigtailed bandpass filter to enhance mode competition, a purely unidirectional tunable fiber ring laser is obtained with high efficiency and broad tunability 相似文献