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。     

LD端面泵浦Cr~4∶YAG被动调Q激光器输出特性研究

对激光二极管端面泵浦Cr4+∶YAG被动调Q Nd∶YAG激光器输出特性进行了实验研究.实验研究发现,激光器输出功率及脉冲重复频率随谐振腔长度增大而增大.为解释这一实验现象,测量了泵浦光斑在激光晶体内尺寸,同时计算了激光晶体及Cr4+∶YAG晶体内的基模激光光斑半径随谐振腔长度变化.分析结果表明:激光晶体内泵浦光斑尺寸远小于激光晶体内基模光斑半径,腔模间交叠效率较低;当腔长增加时,激光晶体内的基模激光光斑减小,腔模间交叠效率增加,从而导致输出功率及脉冲重复频率随腔长增加而增加;另外,Cr4+∶YAG晶体内光斑半径也随谐振腔长度减小,引起Cr4+∶YAG晶体漂白时间缩短,导致脉冲重复频率随腔长增加而增加.     

Cr4+:YAG被动调Q激光器输出特性

采用理论与实验相结合的方法研究了激光二极管阵列泵浦的Cr4+:YAG被动调Q Nd:YAG激光器的输出特性.重点分析了调Q晶体小信号透过率和反射镜的反射率对激光器的输出能量、脉冲宽度的影响.对数值模拟结果进行了实验验证,数值计算与实验结果基本一致.研究结果表明,在特定的激光晶体参数下,Cr4+:YAG被动调Q激光器的输出能量与脉冲宽度由调Q晶体的小信号透过率和输出镜的反射率决定:输出能量随着小信号透过率增加而减小,对应于一个调Q晶体透过率,有一个最佳反射率使输出能量最大;脉冲宽度随着初始透过率与反射率的增大而增大.     

离子注入SI—GaAs做激光器被动调Q元件的研究

本文从半导体材料GaAs的能级结构出发，探讨了GaAs做固体激光器被动调Q器件的可行性，对离子注入半绝缘GaAs用做Nd：YAG激光器中被动调Q元件的机理进行了实验研究，实验中腔型选择直腔式平平腔，Nd：YAG采用脉冲氙灯抽运，在腔型1Hz下获得了单脉冲宽度为62ns的调Q波形输出。     

Cr4+:YAG被动调Q激光器输出特性

采用理论与实验相结合的方法研究了激光二极管阵列泵浦的Cr4+:YAG被动调Q Nd：YAG激光器的输出特性。重点分析了调Q晶体小信号透过率和反射镜的反射率对激光器的输出能量、脉冲宽度的影响。对数值模拟结果进行了实验验证,数值计算与实验结果基本一致。研究结果表明,在特定的激光晶体参数下,Cr4+:YAG被动调Q激光器的输出能量与脉冲宽度由调Q晶体的小信号透过率和输出镜的反射率决定：输出能量随着小信号透过率增加而减小,对应于一个调Q晶体透过率,有一个最佳反射率使输出能量最大;脉冲宽度随着初始透过率与反射率的增大而增大。     

可饱和吸收体Cr∶YAG做被动调Q元件时的选模作用

研究了可饱和吸收体Cr∶YAG做被动调Q元件时所表现出的选模作用.理论分析和实验表明:Cr∶YAG晶体的"动态光阑"效果确保了激光器的基横模输出;而不同纵模形成振荡的难易差别也为脉冲单纵模的实现提供了条件.Cr∶YAG晶体的选模作用在实践中应得到充分的利用.     

LD泵浦的被动调QYb:YAG薄片激光器实验研究

采用中心波长为940nm的激光二极管泵浦,实现了Yb:YAG薄片的Cr4+:YAG被动调Q激光输出.Yb:YAG薄片掺杂Yb3+离子浓度为10%,厚度为500μm.理论上计算了Yb:YAG薄片在直接水冷方式与不同厚度SiC冷却方式下的温度分布.实验中采用厚度800μm的SiC冷却方式,获得了最高功率2.8 W的1 030nm连续激光输出,输出功率相比直接水冷方式提高了40%.通过Degnan理论优化了被动调Q晶体Cr4+:YAG的初始透过率和输出耦合镜,采用初始透过率为93%的Cr4+:YAG晶体和透过率为10%的输出耦合镜,在800μm SiC冷却方式下,获得了平均输出功率1.95 W、单脉冲能量1.2mJ、脉冲宽度74ns、重复频率1.6kHz的稳定调Q脉冲输出,斜效率为18.1%.光束质量因子M2x=1.622,M2y=1.616.     

LD泵浦Nd∶LuVO4/Cr4+∶YAG被动调Q激光器

采用大功率半导体激光器端面泵浦Nd∶LuVO4晶体，利用Cr4+∶YAG晶体作为可饱和吸收元件，实现了1.06 μm激光的被动调Q运转.在泵浦功率为19.1 W时，获得最高平均输出功率为4.58 W，脉冲宽度为84 ns，单脉冲能量为36.6 μJ以及峰值功率为436.2 W的激光脉冲.     

LD抽运Cr4+∶YAG高重复率被动调Q Nd∶YVO4激光器

采用Cr4+∶YAG晶体作为可饱和吸收体，实现连续激光二极管（LD）端面抽运的Nd∶YVO4激光器的高重复率被动调Q.在注入抽运功率为8.8 W时，得到重复频率23.8 kHz、平均功率1.21 W的调Q脉冲序列；每个脉冲能量为51 μJ、脉宽为25 ns、峰值功率达到2.03 kW.实验上研究了脉冲重复频率、平均输出功率、脉冲宽度、单脉冲能量与抽运功率、输出镜透过率的关系.实验结果表明，当抽运功率较大时，脉冲重复频率和输出平均功率随着抽运功率的增加而减小，对此进行了合理的理论解释.     

二极管泵浦被动调QNd∶YAG/KTP绿光激光器（英文）

报道了LD泵浦的Nd∶YAG/KTP/Cr∶YAG结构被动调Q绿光激光器.当注入泵浦功率为750mW时,获得了平均功率38mW,脉冲宽度14.7ns,重复频率20.4kHz,峰值功率126.6W的调Q绿激光输出.     

全固态腔内倍频被动调Q绿光激光器的理论研究

将倍频过程视为一种随基波光子数变化而变化的非线性腔内损耗,对被动调Q四能级速率方程进行修正,总结出了被动调Q绿光激光器的四能级非线性速率方程.通过数值求解,对连续LD泵浦Nd:GdVO4 /Cr4+:YAG/KTP和Nd:YAG/ Cr4+:YAG/LBO腔内倍频被动调Q绿光激光器的输出特性进行了数值模拟.通过与实验数...     

Graphene-based passively Q-switched diode-side-pumped Nd:YAG solid laser

In this paper, a desirably simple, convenient and inexpensive saturable absorber mirror has been fabricated based on graphene, which has no wavelength selectivity. Moreover, there are no changes in the structure and characteristics of graphene. By inserting the graphene-PMMA SA mirror to the Nd: YAG laser, the shortest pulse width of 260 ns can be obtained with the single-pulse energy of about 8.32 μJ. The experimental results prove that our graphene-PMMA SA mirror is feasible and suitable for Q-switched lasers.     

LD side-pumped passively Q-switched Yb:YAG slab laser

A quasi-continuous wave laser diode side-pumped passively Q-switched Yb:YAG slab laser with Cr⁴⁺:YAG saturable absorber has been demonstrated in order to understand the pulse properties of Yb:YAG crystal. To our knowledge the maximum 69% extraction efficiency is achieved by the system. 44 μJ pulse energy and 1.64 KW peak power with near diffraction-limited beam quality are presented at 25 Hz repetition rate. The build-up time of the Q-giant in the passively Q-switched laser is shown.     

A thermally-insensitive passively Q-switched Cr:YAG/Nd:YAG laser

A passively Q-switched laser with Cr⁴⁺:YAG/Nd:YAG composite crystal using a corner cube prism cavity has been realized, in which the corner cube prism is the key element as it aids the compensation of the thermal lens effect of laser crystal. Compared with plane–plane mirror cavities under the same conditions, the stability of the laser performance using the corner cube prism cavity was improved remarkably over temperatures ranging from −40 to 65 °C. The decrease of Nd:YAG stimulated emission cross section with temperature was considered to be the main reason for the increase of average output pulse energy under the same cycle for the two different cavities when the ambient temperature changed −40 to 65 °C. The mode properties produced by the prism cavity were analyzed, and the theoretical results were verified by experimental observations.     

Cr4+：YAG被动调Q激光器中受激粒子上转换效应对脉冲的影响研究

分析和报道了受激粒子能量上转换(ETU)效应对Cr:YAG 被动调Q Nd:YAG/Nd:YVO₄激光器的输出脉冲影响研究.结合ETU理论分析和被动调Q速率方程组，得到了初始反转粒子密度，末态反转粒子密度和光强最大时反转粒子密度的比值变化对激光输出脉冲宽度和脉冲能量的影响，和实验结果相一致.同时讨论了降低ETU效应的方法，有助于这类被动调Q激光器的优化设计. 关键词： 受激粒子能量上转换 Cr:YAG饱和吸收体 被动调Q     

Experimental study of electro-optical Q-switched pulsed Nd:YAG laser

We report the specification of a compact and stable side diode-pumped Q-switched pulsed Nd:YAG laser. We experimentally study and compare the performance of the pulsed Nd:YAG laser in the free-running and Q-switched modes at different pulse repetition rates from 1 Hz to 100 Hz. The laser output energy is stabilized by using a special configuration of the optical resonator. In this laser, an unsymmetrical concave-concave resonator is used and this structure helps the mode volume to be nearly fixed when the pulse repetition rate is increased. According to the experimental results in the Q-switched operation, the laser output energy is nearly constant around 70 mJ with an FWHM pulse width of 7 ns at 100 Hz. The optical-to-optical conversion efficiency in the Q-switched regime is 17.5%.     

Direct numerical simulation of quasi-three-level passive Q-switched laser

The Runge-Kutta method is used to solve numerically the rate equations of quasi-three-level passive Q-switched laser directly without any approximate treatment of these differential equations. The 946 nm self-Q-switched Cr,Nd:YAG laser is chosen for example to describe the details. The time-dependence of intra-cavity photon density is obtained and its detailed real-time changing process is reproduced in numerical solution. The curves of laser output parameters such as average output power, pulse width, repetition rate, pulse energy and peak power changing with different cavity conditions such as pump power, output coupler reflectivity, Cr,Nd:YAG crystal length, Nd³⁺ ion and Cr⁴⁺ ion concentrations are simulated according to direct numerical solution rather than analytical expressions. This direct numerical simulation method can be widely used to describe and optimize the quasi-three-level passive Q-switched laser theoretically.     

分布反馈激光特性的实验研究

研究了以脉冲YAG倍频激光泵浦Rh6G染料,产生分布反馈激光振荡的辐射光谱、转换效率、时间过程以及可调谐特性;发现在大于泵浦阈值下的分布反馈激光输出的多谱线结构与双脉冲辐射现象,以及分布反馈激光脉冲变窄的自开关效应.作为详细的实验观察和分析.     

LD-pumped passively Q-switched Nd:YVO/LBO red laser with V:YAG

An LD-pumped Nd:YVO₄ passively Q-switched by V:YAG and intracavity frequency doubled by LBO red pulse laser at 671 nm was presented. With 1.6 W incident pump power, average output power of 53 mW, pulse duration (FWHM) of 29.5 ns, pulse repetition rate of 37.2 kHz, peak power of 48.3 W and single-pulse energy of 1.43 μJ were obtained. The stability of pulse energy and repetition rate was better than 3% for 4 h.