紧凑型人眼安全OPO激光器

提出了OPO与泵浦源激光器共用一个谐振腔的新型结构,保证了OPO谐振腔和基波谐振腔的腔模最佳匹配,OPO光束质量得到了很大提高。泵浦源激光器,采用布氏角切割的Cr∶YAG晶体作为被动Q开关,定向棱镜作为谐振腔全反镜,使得整个OPO激光器具有结构紧凑、抗失调能力强的特点。1. 57μm激光的输出能量8mJ、发散角5. 5mrad、重复频率1 /6Hz。     

KTP光学参量振荡器输出激光的空间模式和光束质量

理论上通过二维傅里叶变换求解耦合波方程 ,分析了KTP光学参量振荡器 (OPO)信号光的空间分布 ;实验上利用Nd∶YAG倍频激光 ( 5 3 2nm)抽运非临界 (θ =90°,φ=0°) 及临界相位匹配KTP (θ =62 7°,φ=0°) OPO ,测量了参量光的空间分布、远场发散角及M2 因子等参数 ,讨论了抽运功率、谐振腔长、残余光后向二次抽运对OPO参量光的发散角和光束质量因子M2 的影响。     

新型高效的人眼安全OPO固体激光器

免调试谐振腔应用在内腔式Cr4+:YAG被动调Q的KTP光参量振荡(OPO)激光器中,获得综合性明显优于平平腔的结果:电光效率由2.27‰提高到2.70‰,1.57μm激光输出单脉冲能量由18 mJ提高到21.4mJ,脉宽由24ns压缩到7.8 ns,发散角由8 mrad减小到7 mrad.并发现定向棱镜腔激光输出能量、光轴指向、脉宽及波形等稳定性比平平腔均有显著改善.已研制出小型、高效、高稳定性、高光束质量的OPO激光器.     

推广的高斯光束远场发散角理论

本文定义了光腔高斯光束的外发散角和内发散角。利用ABCD矩阵,g-、g~*-参数表示和为实验所支持的多模远场发散角的定义推导出了简单两镜腔和多元件谐振腔基模和多模外发散角和内发散角的一般公式,得出了(1)一般固体激光腔;(2)输出镜为平面反射镜;(3)激     

激光二极管抽运正交波罗棱镜腔光学参量振荡激光器

将正交波罗棱镜谐振腔应用于激光二极管(LD)抽运的光学参量振荡(OPO)激光器,实现了Ⅱ类非临界相位匹配KTP晶体的内腔式光参量振荡,获得了高机械稳定性、高热稳定性和较高光束质量的1.57μm人眼安全激光输出.正交波罗棱镜腔存在腔内振荡光束线偏振运行条件,匀化了内腔OPO的抽运光光场.正交波罗棱镜腔OPO激光器解决了内腔式光参量振荡信号光输出不稳定,以及腔内光功率密度较高容易引起光学损伤等工程应用难题.器件采用热传导冷却半圆柱面LD阵列侧向抽运Nd:YAG抽运几何,在20 Hz运行条件下获得平均脉冲能量86 mJ,脉冲宽度5.4 ns,光束发散角5 mrad.能量稳定性优于±2.5%,光-光转换效率(808 nm→1570 nm)9%的优异性能.     

稳定光学谐振腔高斯光束的发散角理论

当考虑到高斯光束在通过界面时参数的变化后,光学谐振腔输出高斯光束的远场发散角(外发散角)一般不等于自由空间中高斯光束的远场发散角(定义为内发散角),使用ABCD矩阵,g-和g-参数表示,导出了在基模和多模工作时内、外发散角的一般公式并对(1)固体激光腔;(2)输出镜为平面镜;(3)激光棒端面直接镀膜成镜;(4)热透镜腔等四个典型例证作了比较和讨论。     

高光束质量1.57 μm的光参量振荡器

将渐变反射率镜 (VRM)虚共焦非稳腔成功地应用于光参量振荡器 (OPO) ,在工作重复频率 2 0Hz时 ,获得了能量 40mJ,光束发散角 4mrad的 1 5 7μm激光输出。     

1.57 μm内腔式OPO激光输出特性的研究

利用Cr^4＋：YAG调Q的1．06μm Nd：YAG激光腔抽运内腔式KTP晶体-光学参量振荡器（KTP-OPO）系统,实现了人眼安全1．57μm信号光振荡输出。通过分析Cr^4＋：YAG被动调Q特性,在保证单脉冲输出的情况下,讨论了OPO腔长变化对系统输出激光脉冲能量、发散角和脉宽的影响。结果表明,随着OPO腔长的增加,单脉冲输出能量、光束发散角减少,而脉冲宽度增加。     

助航激光器设计

简单介绍了助航激光器的构成,谐振腔的设计思想及谐振腔采用变反镜非稳腔之后对激光光束质量的改进及对远场发散角的压缩。     

利用双光学参量振荡器结构输出4.3μm激光方案

鉴于中红外激光的重要应用价值,提出了分别用2.1 μm和2.7 μm激光泵浦ZnGeO2(ZGP)光学参数振荡器(OPO),采用不同相位匹配方式输出4.3 μm的激光方案,计算并比较了匹配角、走离角、有效非线性系数、泵浦光的允许线宽、允许发散角、参量输出光的线宽以及ZGP对泵浦光的吸收系数等,确定最佳方案为利用1.06...     

角锥棱镜腔Cr4+:YAG被动调Q内腔式光参量振荡器

通过对角锥棱镜腔实现KTPⅡ类非临界相位匹配光参量振荡的理论分析,发现腔内存在特殊偏振方位角的本征模式,其满足Ⅱ类非临界相位匹配条件。实验上不但实现了该腔的Cr4 ∶YAG被动调Q内腔式光参量振荡器(OPO)运转,而且得到了优于平-平腔的转换效率,改善了信号光的稳定性。分析了Cr4 ∶YAG初始透过率和腔内功率密度的关系,实验获得不同Cr4 ∶YAG初始透过率、抽运能量和信号光能量的关系曲线。通过腔内功率密度的优化,电光效率高达0.25%,设计出结构紧凑、小型高效的工程实用光参量振荡器器件,抽运能量阈值为4.7 J,输出能量为11.8 mJ,脉宽为6.9 ns,发散角为7 mrad,能量稳定性为5%。     

Multimode pumping of optical parametric oscillators

Calculations suggest that optical parametric oscillators (OPO's) can be efficiently pumped using multimode, divergent pump sources. The influence of pump beam divergence and mode structure upon OPO performance is measured for both noncritical phase-matching, and OPO's with walkoff. Multimode OPO pumping is shown to be efficient, provided appropriate nonlinear crystals and OPO cavities are employed; the nonlinear crystal must have sufficient angular acceptance to tolerate a divergent pump; the OPO cavity must support modes that match the divergence and spatial intensity characteristics of the pump, For low-order pump modes, the OPO can be made to match the mode of the pump. Higher order pump modes reduce the OPO efficiency, and cause a saturation of efficiency with increasing pump power. The efficiency is degraded in a similar fashion in the presence of walkoff. Multimode pumping is more difficult in longer OPO cavities due to increased buildup time of higher order OPO modes     

紧凑型1.57μmOPO激光器

设计了紧凑型1.57μmOPO激光器,以满足工程化的需要。分别采用两种非稳腔腔型的1.57μmOPO激光器,同样为Cr4+:YAG被动调Q,在7J的电能量输入下,得到输出能量6mJ、发散角3.0mrad和输出能量4mJ、发散角为3.0mrad的两种高光束质量的1.57μm人眼安全激光输出。以极其简单的结构克服了OPO激光器光束质量不好的困难。     

脉冲LD泵浦千赫兹1.57 μm全固态激光器

采用非稳腔光参量振荡（OPO）研制了千赫兹重复频率人眼安全波段全固态激光器。激光器采用电光调Q方式、脉冲激光二极管（LD）侧面泵浦Nd:YAG激光晶体实现了高光束质量的1.064m基频激光。光参量振荡部分采用Ⅱ类非临界相位匹配KTP晶体,为了获得较好的光束质量,OPO谐振腔采用平凸非稳定谐振腔结构,实现了千赫兹重频、窄脉冲1.57m波段激光输出。在脉冲激光二极管泵浦电流为125 A、电光调Q重复频率为1 kHz时,1.57m激光输出最大平均功率达到了4.67 W,激光脉冲宽度为4.3 ns,功率不稳定度为3%,激光泵浦阈值约为45 A。     

Copper vapor laser unstable resonator oscillator and oscillator-amplifier characteristics

We have studied the properties of copper vapor lasers configured as oscillators with unstable resonator optics and as power amplifiers. With the unstable resonator, a 26-fold reduction in the oscillator beam divergence has been achieved over the value observed with stable optics without any power degradation. Time-dependent beam divergence effects in the unstable resonator have also been measured and explained. Small-signal gain, saturation fluence, and available stored energy density parameters have also been measured in oscillator amplifier experiments for both the 510.6 and 578.2 nm transitions as a function of the copper number density. These results quantify the maximum power per unit length available from these devices and furthermore, demonstrate efficient extraction of power from copper vapor lasers operated as amplifiers.     

Single longitudinal mode operation of the electron-beam-pumped semiconductor laser

The influence of the external and internal resonator parameters on the laser emission spectral and spatial characteristics has been investigated. Single longitudinal mode operation of the electron-beam-pumped visible semiconductor laser with an external resonator has been observed. A single-mode peak power of 0.8 W and beam divergence of less than 3° were achieved.     

加固型人眼安全OPO激光器的设计

考虑到军用激光器对可靠性的特殊要求,设计了一种加固型的内腔式人眼安全OPO激光器。采用双定向棱镜折叠谐振腔、Cr4+:YAG被动调Q晶体、Ce-Nd:YAG激光棒、非临界相位匹配KTP光参量振荡晶体,获得5.3mJ/pulse1.57μmOPO激光输出,脉冲宽度约为6ns,发散角约为5mrad,重复频率为3Hz,连续工作时间为1min,且输出能量和光轴指向稳定的结果。该激光器具有结构紧凑、可靠性高的特点。     

Application of a telescopic resonator to high-power chemicaloxygen-iodine lasers

The application of an intraresonator telescope to high-power chemical oxygen-iodine lasers to decrease the output beam divergence is analyzed and demonstrated. A theoretical formula based on the ABCD matrix theory is developed to analyze the characteristics of the telescopic resonator. Calculations are carried out using Galilean type telescopes with magnification factors in the range of two to four, and our high-power chemical oxygen-iodine laser as an analysis model. By locating the telescope at a proper position on the optical axis, the overall telescopic resonator can be conveniently tailored to the hardware of this model laser in a way that the beam divergence and the resonator stability can be improved simultaneously. Experiments are carried out for one of the conditions used in the calculations. Measured divergence angles are in excellent agreement with the theoretical values     

含热透镜多元件谐振腔的动态工作特性

由于光泵浦热效应,高功率固体激光器的输出参数如光束远场发散角、输出功率等会发生变化。本文使用g-参数等价腔详细研究了各种类型稳定腔、临界腔的动态工作特性,例如g-参数图上工作点的运动规律、临界光焦度、临界g参数以及光斑半径、远场发散角等。文中还对理论的实验验证和应用进行了讨论。