共查询到20条相似文献,搜索用时 62 毫秒
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红外短脉冲自由电子激光锁模的解析研究 总被引:1,自引:0,他引:1
本文对一种自由电子激光中的锁模问题进行了解析研究,给出了自由电子激光中的锁模条件;得到了由于模的耦合,腔内激活的模数将减少m_c倍,低增益将增加m_c倍,指数增长速率将增加m_c~(1/3)倍。m_c是电子微脉冲重复频率Δv_r与腔内模的间隔Δv_c的比值,m_c=Δv_r/Δv_c。 相似文献
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主被动锁模光纤激光器的脉宽计算及其稳定性分析 总被引:1,自引:0,他引:1
分析了主被动锁模光纤环形孤子激光器的运行机理,用分裂步长法进行了数值模拟,获得了重复频率为10GHz,脉宽为985fs的稳定的孤子脉冲序列,通过孤子参量演化方程的求解,获得了光结环形孤子激光器的稳定运行条件及孤子脉宽的解析表达式。 相似文献
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基于飞秒锁模固态激光系统,推导了激光脉冲的振幅、脉宽的倒数、啁啾、频率、中心位置和位相的运动方程.在低的白噪声的假设下,估算了含啁啾的钛宝石激光器中由放大的自发辐射引起的时基抖动.结果表明:对于一台脉冲轮廓为sech2(1763t/τ)的确定的锁模固态激光系统,时基抖动近似为净群速延迟色散(GDD)的线性函数,且随着GDD的增加而变大;然而,即便在GDD被完全补偿的情况下,时基抖动也不会是零
关键词:
时基抖时
放大的自发辐射
飞秒锁模固态激光系统 相似文献
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针对常规连续激光泵浦钛宝石激光振荡器不能自启动锁模的缺点,采用倍频飞秒光纤激光同步泵浦,通过调节振荡器腔长与泵浦腔长匹配,实现了飞秒钛宝石激光的自启动锁模。实验中采用3.4 W的倍频掺镱光纤激光同步泵浦钛宝石激光振荡器,获得了平均功率大于130 mW、重复频率75 MHz、光谱宽度大于47 nm、脉冲宽度17 fs的锁模脉冲输出,不仅能够稳定可靠地实现自启动锁模,解决了常规钛宝石激光振荡器锁模启动的困难,而且还具有同步输出1040,800,520 nm三束飞秒激光的特点,为进一步开展飞秒激光相干合成以及光参量放大等研究提供了优势基础。 相似文献
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L. M. Zhao D. Y. Tang T. H. Cheng C. Lu H. Y. Tam X. Q. Fu S. C. Wen 《Optical and Quantum Electronics》2008,40(13):1053-1064
We report on the experimental observation of passive harmonic mode locking of bunches of single-pulse solitons or twin-pulse
solitons in an Erbium-doped fiber ring laser. Experimental investigations on the phenomenon revealed that, although the soliton
interaction between the adjacent single-/twin-pulse solitons in a bunch is weaker than that of the pulse interaction in the
twin-pulse solitons, a soliton bunch could also function as a unit and form the state of passively harmonic mode-locking.
Harmonic mode-locking is one of the intrinsic characteristics of soliton emission in passively mode-locked fiber ring lasers.
It can be formed based on the single-pulse soliton, twin-pulse soliton, or bunch of solitons. 相似文献
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The transition state between the continuous wave region and the mode-locked region in a passively mode-locked erbium-doped fibre ring laser has been experimentally observed by utilizing the nonlinear polarization rotation technique.When the pump power reaches the mode-locked threshold,the metastable pulse train with a tunable repetition rate is obtained in the transition from the continuous wave state to the passive mode-locked state via proper adjustment of the polarization controller.A simple model has been established to explain the experimental observation. 相似文献
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Frank H.G.M. Wijnands Charles G. Crookes Paul M. Charles Richard M. Ash Ian F. Lealman Michael J. Robertson Anthony E. Kelly Kevin A. Williams Aeneas B. Massara Richard V. Penty Ian H. White 《Optical and Quantum Electronics》2002,34(10):959-973
An anomalous modulation in the wavelength spectrum has been observed in lasers with spot-size converters. This intensity modulation is shown to be caused by beating between the fundamental lasing mode and radiation modes in the taper. This results in a periodic modulation in the net gain spectrum, which causes wavelength jumps between adjacent net gain maxima, and a drive current dependent spectral width that is expected to affect system performance. The amplitude of this spectral modulation is reduced significantly by either using an angled rear-facet which reflects the beating radiation modes away from the laser axis, or by using a nonlinear, adiabatic taper. 相似文献
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O. Prakash J. Kumar R. Mahakud P. Saxena V.K. Dubey S.K. Dixit J.K. Mittal 《Optics & Laser Technology》2011,43(8):1475-1481
This paper presents the effect of the flow of the dye gain medium on the wavelength jitter (<30 s) and drift (≈10 min) of a single axial mode dye laser pumped by a copper vapor laser (5.5 kHz). The study was carried out using a wave-meter. The dye solution temperature was maintained to within ±0.1 °C to allow the influence of dye flow rate on the wavelength stability. For the investigated dye flow rate, varying from 1.4 to 2.8 lpm (with corresponding Reynolds number varying from 1975 to 3950), the dye laser wavelength jitter reduced from ±0.15 pm (±130 MHz) to ±0.08 pm (±70 MHz) and drift rate reduced from 1.0 to 0. 2 MHz/s. However for flows beyond 1.7 lpm, random fluctuations in dye laser wavelength were observed. The observed behavior was linked to the flow related variation of angular spread and angular drift of the dye laser beam circulating in the cavity. This was revealed by an exhaustive study of the long term (≈10 min) divergence and pointing stability of the single mode dye laser output beams for different dye media flows. 相似文献
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B.R. Koch A.W. Fang E. Lively R. Jones O. Cohen D.J. Blumenthal J.E. Bowers 《Laser \u0026amp; Photonics Reviews》2009,3(4):355-369
Electrically pumped lasers that can be made on silicon and integrated with other components are important in order to take full advantage of the capabilities of silicon photonics. In this paper we review two specific types of hybrid silicon evanescent lasers that can fulfill these requirements. We discuss recent results of distributed feedback (DFB) lasers and mode locked lasers made on silicon using evanescent coupling to thin films of III‐V material. Device designs and test results are discussed in detail. 相似文献
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Dynamical investigation and parameter stability region analysis of a flywheel energy storage system in charging mode 下载免费PDF全文
In this paper, the dynamic behavior analysis of the electromechanical coupling characteristics of a flywheel energy storage system (FESS) with a permanent magnet (PM) brushless direct-current (DC) motor (BLDCM) is studied. The Hopf bifurcation theory and nonlinear methods are used to investigate the generation process and mechanism of the coupled dynamic behavior for the average current controlled FESS in the charging mode. First, the universal nonlinear dynamic model of the FESS based on the BLDCM is derived. Then, for a 0.01 kWh/1.6 kW FESS platform in the Key Laboratory of the Smart Grid at Tianjin University, the phase trajectory of the FESS from a stable state towards chaos is presented using numerical and stroboscopic methods, and all dynamic behaviors of the system in this process are captured. The characteristics of the low-frequency oscillation and the mechanism of the Hopf bifurcation are investigated based on the Routh stability criterion and nonlinear dynamic theory. It is shown that the Hopf bifurcation is directly due to the loss of control over the inductor current, which is caused by the system control parameters exceeding certain ranges. This coupling nonlinear process of the FESS affects the stability of the motor running and the efficiency of energy transfer. In this paper, we investigate into the effects of control parameter change on the stability and the stability regions of these parameters based on the averaged-model approach. Furthermore, the effect of the quantization error in the digital control system is considered to modify the stability regions of the control parameters. Finally, these theoretical results are verified through platform experiments. 相似文献
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Polarization mode dispersion (PMD) is the ultimate limitation to high bit-rate fibre communication system. The stability of PMD is very important to its measurement and compensation. This paper puts forward a method to measure the stability of PMD by measuring the stability of the state of polarization (SOP) and introduces the conception of time evolution vector (TEV) of SOP. We observe the fact that the regularity of the principal state of polarization changing with time is the same as other SOPs‘‘, if we neglect the dependence of TEV on wavelength. We also measure the SOP‘‘s stability of some fibres with different lengths, and obtain results of PMD changing with time. 相似文献
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A power and wavelength detuning-dependent hysteresis loop in a single mode Fabry-Prot laser diode 下载免费PDF全文
In this paper, we observe experimentally the optical bistability induced by the side-mode injection power and wave-length detuning in a single mode Fabry-Prot laser diode (SMFP-LD). Results show that the bistability characteristics of the dominant and injected modes are strongly dependent on the injected input optical power and wavelength detuning in an SMFP-LD. We observe three types of hysteresis loops: counterclockwise, clockwise, and butterfly hysteresis with various loop widths. In the case of a bistability loop caused by injection power, the transition from counterclockwise to clockwise in the hysteresis direction with the wavelength detuning from 0.028 nm to 0.112 nm is observed in a way of butterfly hysteresis for the dominant mode by increasing the wavelength detuning. The width of hysteresis loop, induced by wavelength detuning is also changed while the injection power is enhanced from 7 dBm to 5 dBm. 相似文献
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We present a theoretical model to study the effect of the pump spectrum and axial mode separation on the single longitudinal mode operation of a laser with a homogeneously broadened semi-monolithic gain medium of short absorption depth. The characterizing parameter is the ratio of the pump power up to which single longitudinal mode is possible to the pump power at the lasing threshold and is denoted by rmax. A numerical study using a Gaussian-shaped pump spectrum reveals that, for a small value of the axial mode separation and for a crystal with short absorption depth at the pump wavelength, the value of rmax reduces significantly with increase in the FWHM of the pump spectrum and thereby results in degradation of the single longitudinal mode performance of the system. However, for large value of the axial mode separation, the SLM performance was found to be nearly independent of the variations in the spectral bandwidth of the pump beam, location of its peak emission wavelength and its polarization. 相似文献