共查询到20条相似文献,搜索用时 93 毫秒
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A new method for measuring the threshold of stimulated Brillouin scattering (SBS) based on the generation location of a Stokes beam is proposed for the first time to our knowledge. The length of the medium cell is selected to be longer than the free gain length of pump pulses in the Brillouin medium. The reflected light from a certain mirror in front of the medium cell is chosen as the reference beam, and the SBS threshold is measured by the "jump" of the delay between the Stokes beam and the reference beam. An 8-ns Q-switched single-longitudinal-mode pulse is used as the pump and the typical SBS medium FC-72 is selected as the nonlinear medium in our experiment. The SBS threshold intensity is measured to be 173-178 mW/cm 2 , which is consistent with existing results measured with the transmitted energy limiting method. 相似文献
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提出了一种可以满足大能量高峰值功率受激布里渊散射(SBS)相位共轭镜要求的独立双池结构,这种结构用在双程激光放大光路中可以补偿单程放大光路产生的动态和静态相位畸变.在7.1 J的入射能量下,最终得到了大于13 J的能量输出.相位共轭镜的能量反射率大于65%,相位共轭保真度达到90%,并且比较了以0°平面反射镜和以SBS相位共轭镜为腔镜的双程激光放大的输出结果,结果表明使用了SBS相位共轭镜之后,即使在大能量抽运的条件下也能得到很好的近场和远场保真度.
关键词:
受激布里渊散射
相位共轭镜
双程放大激光器
保真度 相似文献
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Investigation on high-power load ability of stimulated Brillouin scattering phase conjugating mirror
Y. L. Wang Z. W. Lu Y. Li P. Wu Z. X. Zheng W. M. He 《Applied physics. B, Lasers and optics》2010,98(2-3):391-395
The factors that affect the performance of stimulated Brillouin scattering phase conjugating mirror (SBS-PCM) in high-power condition are demonstrated. In high-power condition, the reflectivity is limited by both the SBS medium and the PCM configuration. FC-72 is found to be the best SBS liquid medium for its very high optical breakdown threshold and very low absorption coefficient by comparing several media. As FC-72 is chosen, the impurity of the liquid is the most remarkable factor which affects the reflectivity of PCM. The Millipore membrane filters with aperture of 0.22 μm was used to clean the liquid, and the reflectivity was evidently increased. Among the parameters of the SBS-PCM, the focal length of lens is one of the most important parameters related to the load ability. In the condition of the input laser of 1 J and 10 Hz, the appropriate focal length is proved to be 50 cm. As lens is chosen, the rotating wedge plate (RWP) is used to decrease the effects of optical breakdown and thermal effects in the condition of high power and stable reflectivity is achieved. Synthetically considering all the factors of medium and configuration, an energy reflectivity of 82% is achieved when the input energy is 0.94 J and the repetition rate is at 10 Hz. 相似文献
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A lidar system based on stimulated Brillouin scattering 总被引:2,自引:0,他引:2
J. Shi G. Li W. Gong J. Bai Y. Huang Y. Liu S. Li D. Liu 《Applied physics. B, Lasers and optics》2007,86(1):177-179
The effect of stimulated Brillouin scattering in remote sensing of the ocean is investigated. It shows that by means of stimulated Brillouin scattering the signal-to-noise ratio of Brillouin lidar can be increased greatly by about 50 times, and its depth resolution can be improved to 1/8 of that with spontaneous Brillouin scattering. PACS 42.68.Wt; 42.79.Qx; 42.65.Es 相似文献
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Marek Roman 《Optics Communications》1982,43(5):333-336
The laser beam intensity changes, due to time resolved stimulated Brillouin scattering, were studied analytically using perturbation approach. It was shown, that the derived expressions enables a qualitative understanding of the previously reported results of the experimental as well as numeric investigations. 相似文献
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从介质化学结构与吸收系数的关系入手,寻找出系列吸收系数小,适合作为放大池介质的新介质,例如四氯乙烯(C2Cl4),1,3-六氯丁二烯(C4Cl6)和六氟化苯(C6F6)等,并计算或测量了入射光波长为1.064μm时的新介质受激布里渊散射(SBS)参数.在双池SBS系统的放大池中分别选用C2Cl4和C4Cl6,振荡池中均选用光学击穿阈值高,并且布里渊频移与C2Cl4和C4Cl6的布里渊频移非常接近的乙醇(C2H5OH),并利用Nd:YAG调Q激光器研究了该系统的性能.实验结果表明,该系统具有高负载能力,高相位共轭保真度和高能量反射率稳定度等性能.
关键词:
受激布里渊散射
双池SBS系统
新介质 相似文献
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基于非线性光学耦合波方程组建立了聚焦泵浦条件下熔石英玻璃材料中SBS过程的物理模型并编制了相应的数值求解程序,研究了SBS介质内激光场的时空发展特征,从而试图揭示SBS介质的内在破坏机制并寻求相应的加固措施.通过数值模拟程序研究了焦点处激光功率密度以及SBS反射率与激光能量的依赖关系,发现SBS对介质内的激光场具有"限幅"作用,即在注入能量大幅度提升的情况下,内部的激光场强度只有较小的增加,这种机制使大能量的固体介质PCM成为可能.分析激光脉宽以及耦合透镜焦距等参数对SBS过程的影响发现,精细选择系统参数,在熔石英玻璃材料中有可能无损伤地实现高效的SBS过程. 相似文献
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从非线性光学的耦合波理论出发,结合流体力学的连续性方程,建立了光学元件中窄带泵浦的横向受激布里渊散射的二维理论模型,并在此基础上,利用数值模拟考察泵浦光带宽增加对受激散射过程的影响。研究表明:在一定的条件下,当泵浦光带宽略大于布里渊线宽时,受激散射过程的Stokes增益将显著降低;带宽越大,Stokes增益降低得越多;当带宽大于20GHz时,可以抑制横向受激布里渊散射带来的不良影响。另外,当带宽一定时,调制频率的改变也会影响受激散射过程,可以通过数值模拟确定最佳的调制频率。 相似文献
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We re-examine behavior of the material response in stimulated Brillouin scattering and from this revise its theoretical formalism. We show that the response out of exact Brillouin resonance splits into two processes: one is the induction of a moving density grating, propagation characteristics of which follow these of the beat pattern of pump and Stokes fields, and the other is the induction of an acoustic wave, frequency of which coincides with that of the beat pattern but which propagates at the acoustic velocity in the medium. The resulting equations for the response amplitudes are solved analytically in several representative cases. 相似文献
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实验研究发现抽运功率密度(或抽运能量)的波动引起的受激布里渊散射(SBS)反射率的不稳定程度受实验参数(抽运能量、介质气压和透镜焦距)的影响.当抽运能量、介质气压和透镜焦距这三个参数同时满足下列条件时可以获得稳定的输出:抽运能量超过5倍的SBS阈值,介质气压在16×105Pa和透镜焦距在15—50cm的范围内;同时还发现当改变实验参数时SBS反射率与稳定性的变化规律完全一致,反射率越高稳定性越好.通过理论分析得到 SBS反射率的相对稳定度实际上是受GIL因子的影响,理论计算与实验符合得很好.
关键词:
KrF激光
受激布里渊散射
反射率
稳定度 相似文献
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把雪崩电离模型引入受激布里渊散射模型中,数值模拟了无光学击穿和有光学击穿时受激布里渊散射能量反射率随输入光功率密度的变化规律.实验上选取净化和未净化的CCl4作为散射介质,在Nd:YAG调Q激光系统中进行了验证,理论与实验符合得很好.结果表明:当无光学击穿时,随着输入光功率密度的增大,能量反射率先是非线性增大,然后缓慢增大趋于饱和;而当有光学击穿时,随着输入光功率密度的增大,能量反射率先是非线性增大,达到最高值之后开始下降,最终趋于零.无光学击穿时的能量反射率及其稳定度明显高于有光学击穿时的情况.
关键词:
受激布里渊散射
光学击穿
雪崩电离 相似文献