光纤中的受激喇曼散射及泵浦脉冲和斯托克斯脉冲的分离

本文报道在单模光纤中的受激喇曼散射的实验结果,用条纹相机测量了泵浦脉冲和喇曼斯托克斯脉冲时间上的相对延迟;结果表明,受激喇曼散射的喇曼斯托克斯脉冲大约在距光纤输入端一个分离距离的位置上形成。     

双折射光纤受激喇曼散射的研究

本文详细地研究了双折射光纤的受激喇曼散射.观测到9级斯托克斯受激喇曼谱.文中讨论和测试了阈值和频移与泵浦光偏振方向间的关系;当泵浦光偏振方向与光纤椭圆核的长轴或短轴平行时的传输损耗.并根据测得的阈值在理论上计算了各级斯托克斯线的喇曼增益系数.     

鉴别CS2介质受激喇曼散射和受激布里渊散射阈值的微小差异的实…

本文提出一个测试ＣＳ２介质受激喇曼散射和受激布里渊散射阈值的微小差异的实验方法，并成功地获得阈值稍低的受激喇曼散射，而抑制了受激布里渊散射。     

注入锁定准分子激光泵浦下氢受激喇曼散射的气压特性

本文研究了注入锁定氟化氪准分子激光泵浦下氢受激喇曼散射的特性。三阶斯托克斯光最大转换效率的氢气压力低于相应的二阶斯托克斯光最大转换效率的氢气压力。通过测量斯托克斯光的光场分布,讨论了上述现象产生的原因。     

高压氢激发态之间的受激喇曼散射

本文采用非稳腔输出的XeCl准分子激光,首次观察到高压氢高激发态之间的受激喇曼散射,并讨论了它们产生的条件.     

金属蒸气受激喇曼散射的原子基态抽空效应

将受激Raman散射原子基态及终态粒子数变化的速率方程与聚焦的泵浦光束及喇曼光束功率变化的微分方程组联立并进行数值求解;研究了金属蒸气受激Raman散射过程中基态粒子数的抽空现象及其对Raman能量转换过程的影响。     

LDS751染料的受激喇曼散射

报道了用532nm激光抽运LDS751染料产生720—780nm可调谐染料激光输出的同时,观察到喇曼频移为102和45cm-1的反斯托克斯线,前者谱线较强,后者较弱.与这两条强线对应的斯托克斯线未能观察到.另外,还观察到喇曼频移为34cm-1的一级和二级斯托克斯线与反斯托克斯线 关键词： LDS751染料 受激喇曼散射 喇曼位移 斯托克斯线 反斯托克斯线     

氢和甲烷混合气体的受激喇曼散射

使用调Q Nd~(3+):YAG激光的二次谐波(532nm)作为泵浦源,探讨了氢和甲烷混合气体的受激喇曼散射效应。利用光学光谱分析仪(OSA)监测,在不同比例的混合气体中,观测到氢和甲烷各自的SRS谱线以及两种气体的联合谱线,[m,n,=0,|±1,±2,…];观察到斯托克斯和反斯托克斯的谱线频移。实验表明两种气体的混合使得氢和甲烷的受激喇曼散射过程发生了竞争和耦合。     

反向泵浦的受激喇曼光声光谱

报道一种改进的受激喇曼光声光谱实验方法 (PhotoacousticRamanSpectroscopy ,PARS) ,该方法的主要特点是将两束激光以反向传播的方式重合 ,从而不仅克服了通常的实验方法 (两束激光通过双色镜片重合 )在测量小喇曼位移方面的限制 ,也使实验的操作更加简单 .在实验中 ,以CH4 分子为研究对象 ,一束波长为 5 3 2 .1nm的激光作为泵浦光 ,另一束可调谐激光作为探测光 (Stokes光 ) ,两束光相向作用于光声池内 ,在 62 5～ 64 2nm和 5 73～ 5 89nm得到了CH4 分子ν1 、ν2 和ν3模的PARS光谱 ,其结果与前人利用自发喇曼散射技术 (ORS)一致 ,其中喇曼活性较弱且喇曼位移较小的ν2 模的PARS光谱是新得到的     

H2的振动及转动受激喇曼散射研究

本文研究了不同泵浦光偏振态及氢气气压时,氢的振动及转动受激喇曼散射的竞争效应.在5atm的氢喇曼池中,以波长为532nm的椭偏激光为泵浦源,当椭圆的压缩系数为tg26°～tg32°时,获得了60多条Q(1)和S(1)混合谱线.并在低压氢及线偏或准线偏光泵浦条件下,观察到迄今尚未见报道的受激R(1)喇曼谱线.     

碰撞对受激Raman散射的影响

从动力学方程出发，引入有效碰撞，讨论了碰撞对受激Raman散射线性增长率的影响.结果表 明，碰撞阻尼和Landau阻尼使得受激Raman散射线性增长率有了实质性的下降，受激Raman散 射只能发生在电子温度和电子密度平面的一个有限区域.现在的理论模型能够解释受激Raman 散射光谱上存在的“缝”(gap)现象. 关键词： 受激Raman散射 碰撞阻尼 线性增长率     

同时辐射六种可见波长的CW-氦氖激光器的稳频及其输出的650nmCW氦氖受激Raman辐射

在中国计量科学研究院研制的612激光管上,利用反射率为99.95%宽带激光反射镜,得到同时辐射六种波长的连续振荡,其波长为:611.8,629.8,632.8,635.1,640.1和650um,测量了它们的物理参数,验证了650nm为氦氖Raman激光.对六种波长在简易装置上进行了稳频,各条激光谱线的频率稳定性优于10~(-10),利用锁模技术,各条激光谱线的频率稳定性可达10~(-12).     

The stimulated Raman scattering competition between solute and solvent in Rhodamine B solution

The competition between the stimulated resonance Raman scattering(SRRS) of Rhodamine B(RhB) and the stimulated Raman scattering(SRS) of ethanol(C2H5OH) is observed at the RhB in C2H5OH solution.For different concentrations of the solution,the peak wavelengths of the SRRS,the amplified spontaneous emission(ASE),the fluorescence and the absorption of RhB are different.The SRRS of RhB and the SRS of C2H5OH are simultaneously generated when the concentration of the solution is 10 5 mol/L and the energy of the excitation laser is 20.4 mJ.Otherwise,only either the SRRS of RhB or the SRS of C2H5OH is generated.The SRRS can be amplified by the ASE gain when the SRRS is near the peak of the ASE,and the peak wavelength of the SRRS coincides with the wavelength of the maximal intensity ASE.     

The stimulated Raman scattering competition between solute and solvent in Rhodamine B solution

The competition between the stimulated resonance Raman scattering (SRRS) of Rhodamine B (RhB) and the stimulated Raman scattering (SRS) of ethanol (C₂H₅OH) is observed at the RhB in C₂H₅OH solution. For different concentrations of the solution, the peak wavelengths of the SRRS, the amplified spontaneous emission (ASE), the fluorescence and the absorption of RhB are different. The SRRS of RhB and the SRS of C₂H₅OH are simultaneously generated when the concentration of the solution is 10^-5 mol/L and the energy of the excitation laser is 20.4 mJ. Otherwise, only either the SRRS of RhB or the SRS of C₂H₅OH is generated. The SRRS can be amplified by the ASE gain when the SRRS is near the peak of the ASE, and the peak wavelength of the SRRS coincides with the wavelength of the maximal intensity ASE.     

Effects of Landau damping and collision on stimulated Raman scattering with various phase-space distributions

Stimulated Raman scattering (SRS) is one of the main instabilities affecting success of fusion ignition. Here, we study the relationship between Raman growth and Landau damping with various distribution functions combining the analytic formulas and Vlasov simulations. The Landau damping obtained by Vlasov-Poisson simulation and Raman growth rate obtained by Vlasov-Maxwell simulation are anti-correlated, which is consistent with our theoretical analysis quantitatively. Maxwellian distribution, flattened distribution, and bi-Maxwellian distribution are studied in detail, which represent three typical stages of SRS. We also demonstrate the effects of plateau width, hot-electron fraction, hot-to-cold electron temperature ratio, and collisional damping on the Landau damping and growth rate. They gives us a deep understanding of SRS and possible ways to mitigate SRS through manipulating distribution functions to a high Landau damping regime.     

水的衰减系数及有效增益长度对受激布里渊散射输出能量的影响

本文从理论和实验上分析了水的衰减系数及有效增益长度对受激布里渊散射(SBS)输出能量的影响。实验结果表明,衰减系数越小,SBS输出能量越高。由于脉宽压缩效应,当入射光能量足够高并且有效增益长度相对较长时,SBS易获得高能量而形成极高的峰值功率。一旦这种峰值功率超过受激拉曼散射(SRS)或者二阶SBS阈值,SBS就会作为一个新的激发源去激发SRS或者二阶SBS,从而消耗掉部分SBS的能量,所以会出现后向有效增益长度越长,SBS的输出能量越低的现象。 关键词： 受激布里渊散射 衰减系数 有效增益长度 脉宽压缩     

同轴正交偏振双脉冲序列受激布里渊散射抽运放大的实现方法

利用受激布里渊散射放大时抽运光与种子光可以有一时间延迟的特性,设计了一个同轴传播正交偏振双脉冲序列的偏振控制装置,使同轴传播的两个正交偏振脉冲光束在放大时具有相同的偏振态,从而实现了两束光的抽运放大.     

Coherent anti‐Stokes Raman scattering in Raman lasers and Raman wavelength converters

In this paper recent research progress on the use of Coherent Anti‐Stokes Raman Scattering (CARS) in Raman lasers and Raman wavelength converters is reviewed. The latest insights in the physical nature and behavior of CARS are addressed, and the recent performance breakthroughs in CARS‐based Raman wavelength conversion are discussed. Based on the new findings regarding the behavior of CARS, a physical explanation for apparent inconsistencies in various experimental observations of Raman wavelength conversion is provided. To conclude it is shown that these recent insights also pave the way to the development of a novel CARS‐based mechanism for reducing the heat dissipation in Raman lasers.     

亚10 fs激光脉冲产生中的受激拉曼散射与四波混频效应

自行搭建的自锁模钛宝石激光器工作在下稳区的上边界附近,采用熔融石英棱镜对在激光器谐振腔的腔内和腔外同时进行群速度色散补偿.随着腔内棱镜对提供色散补偿的变化,输出激光脉冲的频谱会突然展宽至664—840nm,其空间模式也由基横模变化至衍射环状结构,这是受激拉曼散射和四波混频效应导致锁模激光脉冲频谱进一步展宽的结果.在此状态下自锁模钛宝石激光器可实现670—865nm范围的波长调谐.如此宽的频谱为钛宝石激光器产生亚10fs激光脉冲提供了必要的条件. 关键词： 飞秒激光脉冲 受激拉曼散射 四波混频 群速度色散     

Effect of water temperature on pulse duration and energy of stimulated Brillouin scattering

The water temperature has a strong effect on the kinematic viscosity, which is inversely proportional to the phonon lifetime and the gain coefficient. The higher the temperature is, the smaller the kinematic viscosity is, and the larger the phonon lifetime is. At a low pump power and a short focal length, we can derive a single-peak stimulated Brillouin scattering (SBS) pulse. The duration of this single-peak SBS pulse depends mainly on the phonon lifetime of water. With the increase of the water temperature, the duration of such a single-peak SBS pulse will become longer, and the SBS energy will become higher for the gain coefficient, which is related to the phonon lifetime. Therefore, varying the medium temperature can lead to the changes of SBS pulse duration and SBS energy.