克尔介质自锁模激光器的锁模启动及稳定性理论初探

描述了克尔介质自锁模激光器的锁模工作原理，建立了自锁模系统光强分辨率的概念，并指出了光强分辨率对自锁模系统的锁模启动和工作稳定性起着决定性的作用，通过合理控制克尔介质自锁模激光器的腔镜失谐角，可以提高系统的光强分辨率，从而使自锁模系统易于自锁模启动并提高其自锁模工作的稳定性。     

主动锁模光纤激光器的孤子理论分析

系统考虑了光纤激光器腔构参数与锁模脉冲参数的制约关系,建立了完整形式的振幅调制主动锁模光纤激光器的稳态方程;据此方程分析了主动锁模光纤激光器腔参数对锁模孤子脉冲参数的影响;分析了无啁啾孤子脉冲形成条件。     

环形腔自锁模掺钛蓝宝石激光器

实现了环形腔掺钛蓝宝石激光器的自锁模运转。在双向同时锁模时获得脉宽为３６ｆｓ的锁模脉冲；在单向锁模时得到脉宽为３２ｆｓ的锁模脉冲。并对激光器的运转特性进行了分析。     

自启动,长时间稳定,低功率泵浦的超短脉冲掺钛蓝宝石激光器

接钛蓝宝石晶体具有宽增益带（660～1100um）和大的增益截面（～3×10－19cm2），因此用掺钛蓝宝石激光器极易产生超短脉冲、高功率激光。主动锁模、被动锁模、对撞脉冲锁模、耦合腔锁模（APM）以及同步泵浦锁模的掺钛蓝宝石激光器，都已实现超短脉冲激光输出。更引人瞩目的是在掺钛蓝宝石激光器上采用自锁模技术，来获得超短脉冲激光。自锁模掺钛蓝宝石激光器的结构简单、运行稳定，已被广泛应用。目前国际上自锁模掺钛蓝宝石激光器产生的最短脉冲为8．5fs’‘’，对应的光谱宽度为151urn。掺钛蓝宝石激光器能自锁模产生超短脉冲的机理一…     

低抽运三镜腔自锁模掺钛蓝宝石激光器的理论与实验研究

实现了低抽运三镜腔自锁模掺钛蓝宝石激光器的自锁模运转,对该激光器的自锁模区进行了实验研究,并对象散、稳定性、光束参量和克尔自聚焦强度与腔参量的关系进行了系统的理论计算.该计算为自锁模固体激光器的设计和调整提供了理论依据. 关键词：     

非线性镜锁模激光器的锁模条件

通过对非线性镜锁模激光器的稳态分析，找到了它的锁模条件及锁模脉冲的强度极限，为该激光器输出高功率的短脉冲提供了理论依据。     

自锁模激光器

概述了自锁模激光器的新成就（包括我们自已的工作）。在实验上，自锁模钛宝石激光器可以输出１３ｆｓ的短激光脉冲，这是直接从激光器中获得的最短脉冲；自锁模溴化亚铜激光器可以输出高稳定性的激光脉冲，从而彻底否定了自锁模没有实用价值的传统认识。在理论上，自克尔镜模型解释了自聚焦激光介质引起的锁模现象；增益凹陷模型解释了宽带激光介质自吸收起的锁模现象和窄带激光介质增益谱线分裂引起的锁模现象。最后，对它们的输出     

用倍频晶体KTP实现Nd：YAG激光锁模的研究

报道用倍频晶体KTP实现Nd:YAG激光锁模的系统研究,给出了该锁模激光器输出脉宽的表达式,并和实验测量值相比较,计算值跟实验结果符合较好.文中还分析了各种参数对该锁模激光输出性能的影响.     

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.     

非线性镜锁模理论

对于均匀展宽激光器的非线性镜锁模，提出了一种解析分析方法。所得脉冲包络为时间的双曲正割函数。得到了脉冲宽度的简单解析表示，并对结果进行了讨论。 关键词：     

锁模光纤激光器时变动力学

锁模激光器除了可以产生稳定的超短脉冲以外,还可产生一系列重要的非平衡态动力学过程。这些快速变化的动力学过程有助于理解超快激光器和相关非线性系统的动力学,也对超快激光器的稳定性设计有重要指导意义。随着超快探测技术的发展,锁模激光器超快动力学的研究取得了一系列突破。介绍了锁模激光器几个典型的非平衡态动力学过程,包括锁模启动过程,孤子分子动力学,呼吸子超快激光,以及孤子、呼吸子爆炸动力学。这些研究不仅揭示了超快激光器中新的物理机制,也将进一步促进超快激光器、孤子及呼吸子相关理论的发展。     

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.     

Optical phase noise and carrier-envelope offset noise of mode-locked lasers

The timing jitter, optical phase noise, and carrier-envelope offset (CEO) noise of passively mode-locked lasers are closely related. New key results concern analytical calculations of the quantum noise limits for optical phase noise and CEO noise. Earlier results for the optical phase noise of actively mode-locked lasers are generalized, particularly for application to passively mode-locked lasers. It is found, for example, that mode locking with slow absorbers can lead to optical linewidths far above the Schawlow–Townes limit. Furthermore, mode-locked lasers can at the same time have nearly quantum-limited timing jitter and a strong optical excess phase noise. A feedback timing stabilization via cavity length control can, depending on the situation, reduce or greatly increase the optical phase noise, while not affecting the CEO noise. Besides presenting such findings, the paper also tries to clarify some basic aspects of phase noise in mode-locked lasers. PACS 42.50.Lc; 42.60.Fc     

Frequency offset locking of a synchronously pumped mode-locked dye laser

We have developed a scheme of frequency offset locking for transferring the frequency stability of a commercial dye laser to a synchronously pumped mode-locked dye laser. By observing the beat frequency between the two dye lasers, mode stability of less than 2 MHz has been observed for the mode-locked dye laser mode. The use of the mode-locked system as a spectroscopic tool has been demonstrated by observing Doppler-free multiple pulse two photon spectra of the sodium 3S-4D transition.     

Synchronous Injection Locking Operation of Monolithic Diode Lasers Mode-Locked Diode Lasers

Synchronized mode-locking of monolithic mode-locked diode lasers has been demonstrated by injecting the light output from a master monolithic mode-locked diode laser. The master diode laser is a 10 GHZ hybridly mode-locked two section InGaASP quantum well laser. The slave lasers are a 10 GHz two section laser which is similar to the master laser, and a 20 GHz three section colliding pulse mode-locking laser. Both the slave lasers were greatly stabilized at 10 GHz frequency by a synchronous mode-locking mechanism under the injection of master laser pulses.     

Linear picosecond electron-optical chronoscopy at a repetition rate of 140 MHz

A picosecond streak camera operating in synchronism with C.W. mode-locked lasers provides real-time integrated measurement of repetitive luminous phenomena with a temporal resolution of ～ 10 ps. The durations of pulses from an actively mode-locked argon ion laser (514.5 nm) have been measured to be ～ 90 ps and the system is particularly suitable for the measurement of dye fluorescence lifetimes.     

基于阿秒抖动光纤锁模激光器的时钟同步

光纤锁模激光器结构简单, 运转稳定, 且输出的超短脉冲序列具有极高的时钟稳定性, 在抽运探测、脉冲相干合成等要求高精度时钟同步的前沿领域有着广阔的应用前景. 本文通过激光器腔内的电光调制器进行反馈控制, 实现了两台光纤锁模激光器之间的紧密时钟信号同步; 并且通过平衡光学互相关方法, 对残余的时钟误差信号进行了测量, 分辨率达到了13 as. 通过优化激光器的腔内动力学过程及反馈环路的参数, 在[1 Hz, 10 MHz]的积分区间内得到了109 as的残余时钟误差, 对应单台激光器的平均时间抖动为77 as.     

锁模脉冲波长连续可调谐光纤激光器

利用在腔内加入可调谐光纤光栅滤波器使“8”字形腔掺Yb3+光纤激光器在锁模状态下实现波长连续可调谐.实验中,在保证锁模状态稳定的情况下,通过调节可调谐光纤光栅滤波器,使激光器输出锁模脉冲的中心波长在1 047 nm～1 055 nm范围内连续调谐,重复频率稳定维持在4.9 MHz.在中心波长1 053 nm处,测得锁模脉冲输出平均功率为8.02 mW,光谱带宽1 nm,脉冲宽度为259.3 ps.这种“8”字形腔被动锁模光纤激光器在锁模状态下对波长连续可调谐,并可长时间稳定工作.     

Noise of mode-locked lasers (Part II): timing jitter and other fluctuations

This work present a comprehensive discussion of the noise properties of mode-locked lasers, with an emphasis on the effect of quantum noise in passively mode-locked solid-state lasers. Of special interest is the timing jitter, which is coupled to noise in various other pulse parameters. The study is based on analytical results and on numerical tools as described in part one of this study. It results in useful guidelines for the comparison and optimization of different kinds of lasers concerning timing jitter. PACS 43.50.+y, 42.50.Lc, 42.60.Fc     

Mechanisms in passive synchronization of erbium fiber lasers

The optical synchronization of two passively mode-locked erbium fiber lasers in a master-slave geometry is presented. Both lasers were mode-locked via nonlinear polarization rotation and used a shared semiconductor saturable absorber mirror for synchronization. Tight synchronization and transfer of the repetition frequency stability were shown. The contributions of several physical mechanisms to the change in roundtrip time during synchronization are investigated by analyzing the change of different pulse parameters in synchronized state, including carrier envelope offset frequency and spectrum.