全光纤调Q激光器腔内脉宽压缩技术

为了压缩MOPA全光纤调Q激光器脉冲宽度,对谐振腔基本参数进行了研究。首先,根据速率方程理论推导出脉冲宽度的表达式,通过数值解建立表达式参数与脉冲宽度的关系。然后,分析增益光纤长度、腔镜输出透过率、Q开关性能等谐振腔基本参数对全光纤调Q种子源输出脉冲宽度的影响并通过实验来逐一验证结果。最后,通过优化的参数搭建全光纤调Q激光器,在重复频率为20 kHz时,得到脉冲宽度为54 ns、平均功率为0.86 W的种子激光输出。在重复频率为100 kHz时,对脉宽142 ns、平均功率为1.66 W的种子光进行预放大和功率主放大,最终得到平均功率120 W、脉宽180 ns、光谱宽度为0.67 nm的稳定脉冲激光输出。通过提升AOM性能、减小增益光纤长度等参数优化方式构建调Q光纤激光器,能有效压缩谐振腔内脉冲宽度。     

新型结构声光调Q激光器研究

为了提高声光调Q输出脉冲的重复率;通过分析影响脉冲输出特性的因素,提出了采用新颖的掠入射方式、线泵浦源侧面泵浦的特殊谐振腔结构,在泵浦功率50 W时,实现了重复频率500 kHz、脉冲宽度76.82 ns的高重复频率激光脉冲输出.结果表明,缩短脉冲建立时间,提高泵浦功率,可以有效地提高声光调Q激光器的重复频率.     

新型电光陶瓷调Q光纤激光器

报道了基于OptoCeramic(R)电光陶瓷材料的新型调Q光纤激光器.采用976 nm半导体激光器作为抽运源,电光陶瓷调制器作为Q开关,峰值吸收系数1200 Db/m的高掺杂镱纤作为增益介质构成环形腔激光器.增益光纤的高掺杂浓度使得激光器的腔长得到缩短,输出光脉冲的宽度得到压缩.通过调节电光元件的电压,控制材料的折射率,调节谐振腔的损耗,实现Q开关作用.实验中通过改变腔长、抽运功率和重复频率,研究了脉冲的输出特性.获得最窄脉宽104 ns,重复频率3～40 kHz连续可调的调Q脉冲输出.     

调Q脉冲保偏光纤激光器的研究

以808nm半导体激光器为抽运源,掺钕双包层保偏光纤为增益介质,对调Q脉冲保偏光纤激光器进行了理论分析和实验研究.利用TDS5104型示波器探测输出脉冲激光的波形,并用光谱分析仪得到输出脉冲激光的光谱图.利用F-P腔型,在1060nm处获得平均功率为2.55W的脉冲激光输出,重复频率为1kHz时,输出单脉冲能量为2.3mJ,峰值功率为4.7kW.改变腔型,把二色镜倾斜放置兼作输出镜,最终获得了平均功率为3.5W的偏振脉冲激光输出,重复频率为1kHz时,输出单脉冲能量为3.3mJ,脉冲宽度为184ns,其峰 关键词： 激光技术 光纤激光器 掺钕保偏光纤 调Q     

声光调Q CO2激光器的输出特性

采用谐振腔内插入声光调制器（AOM）的方法获得了小型CO2激光器的高重频、窄脉宽、高峰值功率输出。通过分析CO2激光器声光调Q的工作原理,利用基于小信号增益和饱和光强的耦合输出数学模型给出了激光器最佳输出镜透过率的数值解,并运用相关实验装置对该数学模型进行了实验验证。理论分析和实验结果均表明：该声光调Q CO2激光器的最佳输出镜透过率为39%。研究了激光器输出性能随脉冲重复频率的变化规律,当脉冲重复频率〉1 kHz时,激光器输出峰值功率下降,这与CO2分子上能级寿命有关,并受声光调Q开关热效应的影响。实验中获得的激光器脉冲频率在1 Hz～100 kHz可调。在脉冲频率为1 kHz时,获得的激光脉冲宽度为156 ns,脉冲峰值功率为10 kW,且稳定性较好,非常适合于作激光与物质相互作用的光源。     

AlGaInAs半导体饱和吸收体调Q特性的理论与实验研究

利用通过金属化学气相沉积法长成的AlGaInAs饱和吸收体,对808nmLD泵浦的Nd∶YVO4键合晶体进行被动调Q,获得了波长为1.06μm的激光脉冲,测量了脉冲能量、脉冲宽度、脉冲重复率随泵浦功率的变化.当泵浦功率为10.57W时,激光平均输出功率为3.45W,斜效率为39%,重复频率达到最大值101kHz.当泵浦功率为8.07W时,脉冲宽度达到最小值1.76ns.利用速率方程对该激光器进行理论分析,计算出输出脉冲能量、峰值功率、脉冲宽度和重复频率的理论值,实验结果和理论结果基本一致.     

不同脉冲重复频率下抽运方式对全光纤声光调Q激光器性能的影响

在不同初始边界条件下数值求解描述全光纤声光调Q双包层光纤激光器的速率方程,得到前向抽运结构和后向抽运结构下激光器上能级粒子数在增益光纤中的分布,以及脉冲能量、平均功率、脉宽、光纤中储能与脉冲重复频率、抽运合束器对信号光透过率、抽运功率的相互关系.从谐振腔内放大自发辐射光的产生影响谐振腔损耗的角度分析仿真结果,并实验验证两种抽运方式对输出脉冲功率和脉冲宽度的影响.结果表明：不同脉冲重复频率下抽运方式会对全光纤声光调Q激光器性能产生显著影响,为获得较好的脉冲输出性能,在重复频率较低 关键词： 光纤激光器 Q')" href="#">声光调Q 抽运方式     

2 μm波段半导体可饱和吸收镜被动调Q光纤激光器

基于半导体可饱和吸收镜和光纤光栅实现了稳定的2 m波段被动调Q光纤脉冲激光器,输出激光的中心波长为1958.2 nm。随着泵浦功率的增加,输出脉冲的重复频率不断增加,而对应脉冲的宽度不断减小。输出脉冲重复频率的变化范围为20～80 kHz,脉冲宽度的变化范围为490 ns～1 s。当泵浦功率为1.3 W时,调Q光纤激光器的最大平均输出功率为91 mW,脉冲重复频率为80 kHz,脉冲宽度为490 ns,对应的最大单脉冲能量约为1.14 J。     

100 kHz腔倒空薄片激光器理论与实验研究

对100 kHz运转的腔倒空薄片激光器的输出特性进行了理论和实验研究。首先建立起腔倒空薄片激光器的速率方程理论模型，模型中考虑了单位时间谐振腔中新增的自发辐射光子数，对其占总自发辐射光子数的比例进行了分析，并结合一些参数进行了仿真。进一步搭建了重复频率为100 kHz的腔倒空薄片激光器实验装置，获得了平均功率为253 W的纳秒激光脉冲输出，光光效率约为35.2%,脉冲宽度为10.4 ns,单脉冲能量为2.53 mJ,脉冲的峰值功率超过了200 kW,x和y方向的光束质量M²分别为9.77和9.27。针对腔倒空调Q的动力学稳定性问题，研究了普克尔盒开关时间对输出平均功率和输出脉冲稳定性的影响，实验中观察到了倍周期分岔和确定性混沌现象，从理论上对这个现象进行了仿真分析，仿真结果可与实验结果相符。     

低温生长GaAs在Nd∶YVO4激光器中调Q特性的研究

采用一种新型的被动调Q饱和吸收体,低温生长GaAs薄膜，实现了半导体抽运Nd∶YVO4激光器的调Q运转.研究了激光器的调Q特性,调Q抽运阈值为2W.在抽运功率9.2 W时，获得的最短脉冲半峰全宽为15 ns，最大单脉冲能量为4.84 μJ，最高峰值功率为330 W，最大平均输出功率为1.16 W；脉冲重复频率在220 kHz到360 kHz之间.     

AlGaInAs半导体饱和吸收体调Q特性的理论与实验研究究

利用通过金属化学气相沉积法长成的AlGaInAs饱和吸收体,对808 nm LD泵浦的Nd:YVO₄键合晶体进行被动调Q,获得了波长为1.06 mm的激光脉冲,测量了脉冲能量、脉冲宽度、脉冲重复率随泵浦功率的变化。当泵浦功率为10.57 W时,激光平均输出功率为3.45 W,斜效率为39 %,重复频率达到最大值101 kHz。当泵浦功率为8.07 W时,脉冲宽度达到最小值1.76 ns。利用速率方程对该激光器进行理论分析,计算出输出脉冲能量、峰值功率、脉冲宽度和重复频率的理论值,实验结果和理论结果基本一致。     

A diode-pumped linear intracavity frequency doubled Nd:YAG rod laser with 40 ns pulse width and 73 W green output power

We analyzed a linear cavity for intracavity frequency doubling of a diode-pumped acousto-optic Q-switched Nd:YAG rod laser, and showed that a green laser beam with a short pulse width can be generated efficiently. A green laser output power of 73 W corresponding to the 83.9% of maximum IR output power was obtained with a 40 ns pulse width at a 10 kHz repetition rate. A green output power of 40 W with a 35 ns pulse width was measured at a 5 kHz repetition rate. Minimum laser pulse width of approximately 32 ns was obtained around 1 kHz repetition rate for both green and IR laser beams.     

100 W全光纤声光调Q光纤激光器实验研究

 报道了一台全光纤结构主振荡功率放大(MOPA)型掺镱脉冲光纤激光器,以光纤光栅为腔镜,光纤型声光调Q的光纤激光器为种子源,通过两级掺镱双包层光纤放大器实现功率放大。对声光调Q的光纤激光器输出特性进行了研究,比较了不同泵浦波长、不同重复频率对激光输出功率和脉冲宽度的影响,并实现了最短脉冲宽度25 ns、单脉冲能量45 μJ的脉冲激光输出。在重复频率50 kHz时,对脉冲宽度130 ns、平均功率0.6 W的种子光进行放大,得到了平均功率102.5 W、脉冲宽度约240 ns的激光输出。     

Room-temperature cw and pulsed operation of a diode-end-pumped Tm:YAP laser

We report the continuous-wave and acousto-optical Q-switched operation of a diode-end-pumped Tm:YAP laser. Continuous-wave output power of 3.5 W at 1.99 μm was obtained under the absorbed pump power of 14 W. Under Q-switched laser operation, the average output power increased from 1.57 W to 2.0 W, with an absorbed pump power of 12.6 W, as the repetition rate increased from 1 kHz to 10 kHz. The maximum Q-switched pulse energy was 1.57 mJ with a repetition rate of 1 kHz. The minimum pulse width was measured to be about 80 ns, corresponding to a peak power of 19.6 kW. PACS 42.55.Rz; 42.55.Xi; 42.60.Gd     

6.5-ns actively Q-switched Nd:YVO_4 laser operating at 1.34 μm

With a plano-concave cavity,diode-pumped continuous-wave(CW) and actively Q-switched Nd:YVO4 laser operating at 1.34 μm is demonstrated.Maximum CW output power of 4.76 W and Q-switched average output power of 2.64 W are obtained with output coupler(transmission T = 3.9%).For the Q-switching operation,the theoretically calculated pulse energy and pulse width,with a pulse repetition frequency(PRF) range of 5-40 kHz,coincide with the experimental results.With a T = 11.9% output coupler,the maximum peak power of 24.3 kW and minimum pulse width of 6.5 ns are obtained when the PRF is 10 kHz.To the best of our knowledge,this is the shortest actively Q-switched pulse duration ever obtained in a 1.3-μm Nd-doped vanadate laser.     

Diode-pumped simultaneously Q-switched and mode-locked Nd:GdVO<Subscript>4</Subscript>/LBO red Laser

A diode-end-pumped simultaneously Q-switched and mode-locked intracavity frequency doubled Nd:GdVO₄/LBO red laser with an acousto-optic Q-switch was realized. The maximum red laser output power of 250 mW was obtained at the incident pump power of 8.3 W and the repetition rate of 10 kHz. At 5 kHz, the maximum mode-locking modulation depth of about 80% was achieved with the Q-switched pulse width of 440 ns. The red mode-locked pulse inside the Q-switched pulse had a repetition rate of 115 MHz, its average pulse width was estimated to be about 350 ps.     

Theoretical and experimental study of single mode-locking pulse generation with low repetition rate in a dual-loss-modulated QML YVO4/Nd:YVO4 laser with EO and GaAs

Using electro-optic (EO) modulator and GaAs saturable absorber, a diode-pumped doubly Q-switched and mode-locked (QML) YVO₄/Nd:YVO₄ laser at 1.06 μm is realized. The experimental results show that the number of the mode-locking pulses underneath the Q-switched envelope decreased with increasing pump power. With an output coupling of 6.5 %, the single mode-locking pulse underneath the Q-switched envelope with 1 kHz repetition rate was obtained when the pump power exceeded 4.65 W. At a pump power of 8.25 W for an output coupling of 10 %, a stable mode-locking pulse train at a repetition rate of 1 kHz was achieved with pulse energy as high as 582 μJ and pulse duration of about 580 ps, corresponding to a peak power of 1 MW. Using a hyperbolic secant square function and considering the Gaussian distribution of the intracavity photon density, the coupled rate equations for diode-pumped doubly QML YVO₄/Nd:YVO₄ laser are given and the numerical solutions of the equations are basically in accordance with the experimental results.     

LD-pumped passively Q-switched Nd:YVO4 infrared and green lasers

A laser diode directly end-pumped, passively Q-switched Nd:YVO₄/Cr:YAG laser is presented in this paper. With 600 mW incident pump laser, Q-switched 1064 nm laser with an average power of 138 mW, pulse width of 19.8 ns, repetition rate of 170.1 kHz and peak power of 40.96 W is obtained. When a KTP crystal was inserted into the cavity, Q-switched 532 nm laser with an average power of 56 mW, pulse width of 28.4 ns, repetition rate of 118.2 kHz and peak power of 16.7 W is obtained at last.