高功率二极管泵浦固体激光谐振腔的进展和分析

对近年来用于高功率二极管泵浦固体激光器的新型光腔，如棒成象非稳腔，近共心非稳腔，折迭腔以及ＳＢＳ相位共轭ＭＯＰＡ系统等进行了深入的分析，并对实现高功率输出和高光束质量的相关技术作了讨论。     

非稳腔激光器激光感应损伤的测量

1.非稳腔图1示出稳定腔和非稳腔的典型反射镜结构。在稳定腔中光是接近光轴传播,并由透明端反射镜耦合输出,在非稳腔中,光路是分散的,能量通过高反射的端反射镜经几次反射之后耦合输出。     

离轴非稳腔导引光多光束干涉与远场图样研究

研究光腔内导引光的往返振荡物理过程与传播特性有助于理解、判断光腔的准直失调状态。离轴非稳腔作为一种兼具高提取效率与高光束质量的混合非稳腔,调腔导引光在离轴非稳腔中的振荡物理过程研究鲜有报道。通过理论计算与实验研究了导引光在离轴非稳腔内的多光束干涉过程及其远场传播特征,在实验中搭建了离轴非稳腔（X方向为平凹稳定腔,Y方向为共焦非稳腔）导引光研究装置,通过凹球面镜小孔注入波长为632.8 nm的基模高斯光束,开展了光腔准直与导引光远场图样研究,实验结果与计算结果吻合较好。计算与实验结果表明：离轴非稳腔的干涉图样与传统共焦非稳腔/稳定腔不同,调腔导引光在腔镜小孔注入处出现椭圆“水滴”状干涉图样,该图样亮度较高,可以用于判断光腔的准直状态。输出导引光的远场光斑在Y方向上是不同振荡阶次的亮核光斑,其中高阶次亮核光斑可用于指示红外激光的远场光斑位置。     

非稳腔-稳腔混合腔失调特性理论研究

非稳腔-稳腔混合腔的失调特性得到了理论上的研究.当调节混合腔的输出耦合镜几何参数改变时,通过Fox-Li数值迭代法计算其基横模的损耗来研究腔的失调特性.发现混合腔在稳腔方向上不易失调;混合腔的不稳定主要来自于非稳腔方向,且主要来自于输出耦合镜在非稳腔平面内的转动,或者垂直于光轴的平移;偏轴非稳腔要比对称非稳腔稳定.利用混合腔中非稳腔方向易失调的特性,可以设计调Q方案.在正支共焦偏轴非稳腔-稳腔混合腔中应用声光调制器在非稳腔平面内实现声光调Q的可行性,得到了理论的证明.     

高功率固体激光谐振腔研究的进展

基于我们的工作和体会，对高功率固体激光腔研究的某些新进展，包括自成像和自滤波非稳腔，共轴和离轴非稳腔，折迭和离轴棱镜腔，非轴对称像散腔，可变反射率镜腔和渐变位相镜腔等作了详细评述和分析。最后，对实现高功率和高光束质量输出的物理思想和技术原理作了总结，并指出了可能的应用。     

凸-ARR非稳腔中Cr~(4+)∶YAG调Q激光器的研究

在带抗共振环 (Anti resonantRing ,ARR)的非稳腔Nd∶YAG激光器中 ,采用Cr4+ ∶YAG作为被动调 Q 元件 ,获得单脉冲能量 >85mJ,脉宽 40ns和能量起伏 0 4%的高能量、高稳定调Q激光脉冲。同时对平 凸非稳腔和平 平介稳腔进行实验比较 ,并对腔型和实验结果进行了初步分析。     

非稳腔的热稳定性分析

本文以非稳腔的放大率为特征量,讨论了非稳腔的热稳问题,求出了非稳腔热稳条件的解析解。     

用混合型非稳腔改善准分子激光的输出特性

通过远场光束质量测量,比较了稳定腔、平行平面腔和混合型非稳腔的输出特性。实验结果表明对于高增益的准分子激光,采用部份透射镜作耦合输出的混合型非稳腔可以使准分子激光的发散角减小到毫弧度量级。     

百瓦级环形非稳腔板条激光器腔内校正

提出一种环形非稳腔结构,该结构将传统驻波非稳腔腔内的非共轭像差校正转换为共轭像差校正。搭建了百瓦级环形非稳腔Nd:YAG板条激光器,采用59单元自适应光学系统对腔内像差进行校正。利用980 nm参考光束和Shack-Hartmann波前传感器测量腔内像差,采用加权最小二乘法复原波前像差,最后用倾斜镜和变形镜进行校正。最终在低抽运功率下将输出功率从105.8 W提高到113.1 W,光束质量β因子从6.98优化到2.33。该研究为环形非稳腔应用于高功率固体激光器并获取高输出光束质量提供了一种技术途径。     

凸-ARR非稳腔中Cr4+:YAG调Q激光器的研究*

在带抗共振环(Anti-resonant Ring,ARR)的非稳腔Nd:YAG激光器中,采用C,+:YAG作为被动调Q元件,获得单脉冲能量>85 mJ,脉宽40ns和能量起伏0.4%的高能量、高稳定调Q激光脉冲.同时对平-凸非稳腔和平-平介稳腔进行实验比较,并对腔型和实验结果进行了初步分析.     

A comparative study of D2O oscillators emitting at 385 µm

The generation of single-mode pulses of far-infrared (FIR) radiation of duration up to 700 ns at 385 μm has been achieved using a confocal unstable resonator with D2O as an active medium. Future volumetric scaling to the power levels necessary for measuring ion temperature in tokamak plasmas by Thomson scattering appears encouraging. A comparison between the performance of the unstable resonator and two hemispherical resonators is reported.     

Mode control and performance studies of a pulsed unstable resonator HF/DF laser

In this paper we consider the design of unstable resonators for use on pulsed HF/DF chemical lasers. The limits on the resonator magnification, as set by mode-growth time requirements and parasitic oscillation, are evaluated and the predictions compared with experimental results obtained using a fast pumped transverse discharge HF laser. A detailed experimental study of the laser performance with a 2.2 magnification unstable resonator has been carried out for both HF and DF operation and optimum operating conditions for energy and peak power extraction defined. Time resolved studies of the multiline HF and DF laser emission spectra are reported. The system described should prove useful in experiments which require a high intensity focused beam.     

Time resolved beam divergence from a copper vapor laser withunstable resonator

The temporal evolution of the far-field intensity distribution (and hence beam divergence) for the output of a CVL operating with both on-axis and off-axis unstable resonators is investigated in detail. The CVL output pulse consists of several temporally resolved components, where each successive component has lower divergence approaching the diffraction limit. A comprehensive model for the divergence of each temporal component from a CVL operating with a variety of unstable resonators is presented. In this model the resonator controls the output divergence by imposing geometric constraints on the propagation of spontaneous emission on repeated round-trips through the unstable resonator equivalent lensguide. Effects of resonator asymmetry and radial gain variations on the far-field intensity distribution (and hence divergence) are evaluated. Experimental measurements of the temporal evolution of output divergence from a CVL operating with both on-axis and off-axis unstable resonators and for a variety of excitation conditions are also presented. For CVL operation at high pulse repetition frequency the ASE at the start of the laser pulse has an annular profile. This annular gain distribution is found to modify the output far-field intensity distribution of the earlier temporal components of the laser pulse. For on-axis unstable resonators these components are found to have annular far-field intensity distributions, whereas for off-axis unstable resonators they have greatly reduced but anisotropic divergence     

基于Visual Basic的激光谐振腔数据库的建立

使用可视化程序设计软件Visual Basic,建立了与激光谐振腔设计软件MatLaser相对应的谐振腔数据库MatLaser Data Base。数据库以稳定驻波腔、稳定行波腔、非稳驻波腔、非稳行波腔、相位共厄腔、光束传输为大类,以激光波长、工作物质、输出功率、激光器工作状态、作者和参考文献等为小类,同时将原文献中谐...     

分析光学谐振腔的矩阵方法(1)

本文总结了将矩阵方法用于研究光腔问题的一些新的进展情况。证明了在普遍情况下描述光腔主要特征的光束参数、失调灵敏度等都能表示为ABCD矩阵元或光腔g参数的形式。对一些典型的光腔,例如含热透镜的望远镜腔(TRTL)、交叉棱镜腔(CPR)、相位共轭腔(PCR)和共焦型多元件非稳腔(CMUR)等作了详细的分析和讨论。     

射频激励扩散冷却平板CO2激光器谐振腔的分析

对适于平板结构射频激励扩散冷却CO2激光器的稳定-非稳混合谐振腔进行了理论分析。给出了腔参数与模参数之间的关系,为这种腔的设计提供了理论依据。研究表明:该谐振腔不仅能有效提取激活区的能量,且可输出单光束偏心椭圆像散光束,获得较高质量的激光。     

腔内扰动对虚共焦腔模式的影响及Zernike像差拟合

为实现高功率或高能激光器输出良好的光束质量和能量,分析了腔内像差扰动对非稳腔模式的影响,采用数值迭代法理论计算了腔内倾斜扰动对无源虚共焦非稳腔输出模式强度和相位分布的影响,并采用Zernike模式法对光束相位进行了像差拟合分解,得到了前35阶像差系数,通过进一步计算得到点扩散函数和环围能量曲线等,从而全面了解输出光束质量.结果表明,对小菲涅耳数虚共焦型非稳腔,腔内倾斜扰动不仅带来输出光强分布的不均匀性,且对相位分布有明显的影响,使相位中的一些高阶Zernike像差如A3,A7和A10等增大.计算结果对研究高能激光器腔内像差校正有一定参考意义.     

An experimental study of unstable confocal CO2resonators

The results of an experimental study to determine the spatial properties of unstable confocal resonator modes and their influence upon both the fractional output coupling and the far-field angular divergence are presented. The radial intensity distributions of the lowest order circulating mode within CO2unstable resonators and the corresponding near- and far-field patterns have been measured. The radial profiles exhibit a significantly nonuniform intensity distribution consistent with the results of recent theoretical analysis. The far-field intensity distribution as well as the fractional output coupling have been investigated for a number of unstable confocal resonator geometries. For modes contained within the uniform-gain region of the laser tube, the experimental results are in excellent agreement with Siegman's unstable resonator analysis.