非腔长匹配相干叠加脉冲锁模激光器的理论研究

提出了一个新的非腔长匹配相干叠加脉冲锁模激光器的物理模型,建立了它的数学方程,并进行了模拟计算.计算结果给出了各个参数对相干叠加脉冲锁模激光器运转的影响,以及脉冲宽度压缩速度和各参数之间的关系,获得了实现非腔长匹配相干叠加脉冲锁模激光器运转的最佳条件.     

对撞脉冲锁模Nd:YAG激光器的实验研究

本文报道了对撞脉冲锁模Nd:YAG激光器的实验装置,试验了影响对撞脉冲锁模激光器性能的各种参量.在最佳参量运转时获得了最短的脉宽为8ps,输出能量的稳定性～±7%.     

大模场面积光子晶体光纤激光器展宽脉冲锁模域的束缚态运转

实验研究了大模面积光子晶体光纤飞秒激光器在近零色散点展宽脉冲锁模的束缚态运转.获得了双脉冲束缚态锁模,以及脉冲间隔不相等的多脉冲束缚态锁模,实验发现束缚态的子脉冲间距具有随机性.通过建立光纤锁模激光器的数值模型,分析了激光器束缚态锁模建立的动力学过程,在一定抽运强度下,激光器存在多个稳态,或者单脉冲运转,或者子脉冲间隔不相等的束缚态运转,这取决于锁模建立阶段半导体可饱和吸收镜(SESAM)对噪声信号的随机提取.并提出了抑制束缚态的方法,模拟得出此项技术可直接获得的最大单脉冲能量为19.6 nJ,考虑到40%左右的压缩损耗,可得到压缩至76 fs的最短脉冲,单脉冲能量为11.8 nJ.数值模拟结果能很好的与实验相符合.     

对撞脉冲锁模Nd:YAG激光器的若干运转特性

本文报道对撞脉冲锁模Nd:YAG激光器的详细实验研究,给出在可饱和吸收体的不同位置、厚度和浓度下,以及在不同的泵浦能量下的运转持性.用这种激光器通常能输出脉宽为11～12ps的锁模激光脉冲.     

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。     

环形腔自锁模渗钛蓝宝石激光器

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宽为３６ｆｓ的我没模脉冲，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。     

自调Q自锁模固体激光器

利用被动锁模激光器的锁模原理,结合自锁模固体激光器中等效快可饱和吸收体的特性,讨论了控制运转状态的自锁模动力学方程和速率方程,给出了自调Q自锁模的条件,以及自调Q周期与激光器结构和运转参数的关系,所得结论与实验结果有很好的一致性。     

脉冲LDA泵浦Nd∶YVO4/GaAs被动调Q锁模激光器

用脉冲激光二极管阵列（LDA）作为泵浦源、微柱透镜阵列和透镜导管作为耦合系统,以As＋注入GaAs可饱和吸收片作为被动调Q锁模元件,实现了Nd∶YVO4激光器调Q锁模运转.调Q运转阶段,激光器每泵浦脉宽内输出一个调Q脉冲,调Q脉宽7ns.调Q锁模运转阶段,初始透过率60％的GaAs晶片对调Q包络内的锁模脉冲的调制深度达到95％以上,锁模脉冲重复频率991 MHz.研究了加在LDA上的电压、方波脉冲的脉宽和重复频率对调Q锁模脉冲特性的影响,并对实验结果进行了讨论.     

基于非线性偏振旋转锁模的高功率光子晶体光纤飞秒激光振荡器

为了探索大模场面积光子晶体光纤锁模激光器在全正色散锁模域内的耗散孤子锁模机理, 以获得更大的单脉冲能量和更高的峰值功率, 本文搭建了以掺镱大模场面积光子晶体光纤作为增益介质的耗散孤子锁模激光器. 激光器使用环形腔结构, 利用非线性偏振旋转以及滤光片提供的耗散作用实现了稳定的锁模运转. 实验中, 从激光器振荡级直接获得了平均功率10 W, 重复频率49.09 MHz(对应202 nJ的单脉冲能量), 脉冲宽度为1.03 ps的稳定锁模脉冲输出, 经过腔外色散补偿得到的脉冲宽度为95.5 fs.     

飞秒被动锁模环形腔掺Er3＋光纤激光器

在考虑增益、损耗、群速度色散、自相位调制、快速可饱和吸收体等各种参数同时作用情况下，分析了非线性偏振旋转效应自启动锁模机理，研究了腔体参数与锁模脉冲之间的关系，并给出飞秒被动锁模环形腔掺Er3＋光纤激光器实验原理。实验采用性能稳定的980nm半导体激光器作为抽运源，高掺杂短长度掺Er3＋光纤作为增益介质，利用非线性偏振旋转锁模技术，得到了稳定的飞秒自起振锁模光脉冲。抽运功率为23mW时，激光器输出锁模脉冲中心波长1552nm，3dB带宽为7.6nm，重复频率14.0MHz，平均输出功率0.43mW，自起振锁模泵浦阈值功率11.5mW,并观测到了稳定的高阶锁模脉冲输出。该激光器与报道过的相同结构光纤激光器相比,自起振泵浦阈值低、脉冲能量高、稳定性好，且频谱边带幅度小。     

Investigation on a colliding pulse mode-locking(Ce~(3 ),Nd~(3 )):YAG laser using an unstable resonator

An investigation on the characteristics of a passive colliding pulse mode-locking(Ce~(3 ),Nd~(3 )):YAG laser using an unstable resonator containing an antiresonant ring hasbeen completed.Using a Ф3×40mm active medium and the pentanethine cyanine dissolved in1,2-dichloethane as a saturable absorber,9 picosecond pulse-width and 3.2 mJ output energywere obtained.The optimum initial transmission of the absorbing cell was determined.     

Theory of active-passive mode-locking of solid-state lasers using a nonlinear mirror

The theory of active-passive mode-locked solid-state lasers is developed where the passive mode-locking is achieved by a nonlinear mirror. Steady-state cw numerical solutions are analyzed in detail for the case of a Nd: YAG laser. The steady-state pulse duration can be reduced by an order of magnitude as compared to the pure active mode-locking regime.On leave from Department of Quantum Electronics, Faculty of Physics, University of Sofia, BG-1126 Sofia, Bulgaria     

Investigation of Cr:YAG passive mode-locking in a pulsed Nd:YAG laser

Passive mode-locking of a pulsed Nd:YAG laser using a Cr⁴⁺:YAG saturable absorber was realized for the first time in a nearly critical stable resonator containing an antiresonant ring structure. The output energy and pulse duration are 13.5 mJ and 180 ps, respectively. The recovery time and saturable intensity for excited-state absorption of Cr⁴⁺:YAG under the action of strong laser pulses were calculated from rate equations.     

4-W and 23-ps pulses from a lamp-pumped Nd:YAG laser passively mode-locked by polarization switching in a KTP crystal

Passive mode-locking of a cw lamp-pumped Nd:YAG laser using nonlinear polarization switching in a type-II SHG crystal is reported. Light pulses with more than 5 W of average power and pulse duration shorter than 25 ps have been obtained at 1064 nm. Received: 29 January 1999 / Revised version: 24 March 1999 / Published online: 1 July 1999     

Properties of Nd：YAG Laser with the Nonlinear Absorption of the Intracavity Fullerenes

ＰｒｏｐｅｒｔｉｅｓｏｆＮｄ：ＹＡＧＬａｓｅｒｗｉｔｈｔｈｅＮｏｎｌｉｎｅａｒＡｂｓｏｒｐｔｉｏｎｏｆｔｈｅＩｎｔｒａｃａｖｉｔｙＦｕｌｌｅｒｅｎｅｓ￥ＬＵＯＴｉｎｇ；ＹＵＺｈｅｎｘｉｎ（ＳｔａｔｅＫｅｙＬａｂｉｒａｔｏｒｙｏｆＵｌｔｒａｆａｓｔＬａ...     

Experiment Study on Active-passive Mode-locking Using Cr4+:YAG as Saturable Absorber

Cr4+:YAG crystal was used as a saturable absorber in an active-passive mode-locked Nd:YAG laser. The stable and complete mode-locked pulse train was achieved at 1064 nm. The duration of ～0.8 ns to 2.4 ns for a single pulse was obtained by using Cr4+:YAG crystals with the different initial transmissions, and there was a shortest pulse width. The mode-locking dynamic process of Cr4+:YAG crystal was discussed to explain the experimental result, and the effect of excited-state absorption was considered.     

Unidirectional travelling wave operation of a mode-locking Nd:Glass ring laser

The development of unidirectional mode-locked pulses in a Nd:glass ring laser is studied for various combinations of active and passive mode-locking and pulse direction discrimination elements.     

关于被动锁模激光器涨落模型的补充说明

本文考虑了在被动锁模涨落模型中涨落脉冲集合中的脉冲数目对锁模的影响,并研究了激光器腔长对于锁模窗口和锁模阈值的影响。 关键词：     

Comparative studies of semiconductor saturable absorber mirror mode-locking dynamics in pulsed diode-end-pumped picosecond Nd:GdVO4 and Nd:YAG lasers

Ultrashort pulses were generated in passively mode-locked Nd:YAG and Nd:GdVO4 lasers pumped by a pulsed laser diode with 10-Hz repetition rate. Stable mode-locked pulse trains were produced with the pulse width of 10 ps. The evolution of the mode-locked pulse was observed in the experiment and was discussed in detail. Comparing the pulse evolutions of Nd:YAG and Nd:GdVO4 lasers, we found that the buildup time of the steady-state mode-locking with semiconductor saturable absorber mirrors (SESAMs) was relevant to the upper-state lifetime and the emission cross-section of the gain medium.     

Nd,Cr:YAG自调Q自锁模激光器的研究

实验采用光纤耦合激光二极管泵浦,得到了二极管泵浦Nd,CrYAG自调Q自锁模1.064 μm激光输出,其锁模调制深度达到了近100%,其输出功率最高可达1.9 W,平均输出功率稳定性优于1%.实验表明平均输出功率、重复频率和脉冲宽度随泵浦功率增加而上升.