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基于暗脉冲的布里渊时域分析仪系统中泵浦光和探测光的功率较高,相互作用强烈,严重限制了系统的有效传感距离。而现有的系统众多采用利用多段具有不同布里渊散射频率的光纤相互连接延长传感距离的方法,降低每段光纤上的受激布里渊散射效应,延长有效传感距离,但这种方案会增加的系统的复杂度,影响实际应用.本文提出一种简单的暗脉冲光布里渊时域分析仪的结构,可在满足高空间分辨率的条件下,有效的延长系统的传感距离,取代通常的利用多段具有不同布里渊散射频率的光纤相互连接延长传感距离的方法.利用基于光抑制载波的技术,产生具有两个边带的斯托克斯光.斯托克斯光的两个边带和泵浦光相互作用,同时激发布里渊散射增益和衰减效应,在接收端利用两者接收信号的差,可抵消原有暗脉冲泵浦信号中准连续光对传感距离的影响,从而有效地延长系统的传感距离,并利用数值仿真的方法验证了此方法的有效性. 相似文献
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受激拉曼散射和热效应会限制光纤激光器功率的提高。利用高功率光纤激光器的速率方程和热传导方程,理论研究了双端泵浦和分布泵浦下双包层光纤激光器的受激拉曼散射和热效应,得到了光纤中的泵浦光、激光和斯托克斯光的功率分布,光纤激光器的输出特性以及光纤中的温度分布。分析表明,当泵浦功率增大到一定值时,光纤激光器中出现SRS,一部分激光功率会转移给斯托克斯光,影响激光功率进一步提高;与双端泵浦方式相比,分布泵浦下光纤激光器的斜率效率和最大输出功率相差不大,但是,光纤中的温度分布被有效地降低,因此,分布泵浦方式更为有效。 相似文献
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受激拉曼散射和热效应会限制光纤激光器功率的提高。利用高功率光纤激光器的速率方程和热传导方程,理论研究了双端泵浦和分布泵浦下双包层光纤激光器的受激拉曼散射和热效应,得到了光纤中的泵浦光、激光和斯托克斯光的功率分布,光纤激光器的输出特性以及光纤中的温度分布。分析表明,当泵浦功率增大到一定值时,光纤激光器中出现SRS,一部分激光功率会转移给斯托克斯光,影响激光功率进一步提高;与双端泵浦方式相比,分布泵浦下光纤激光器的斜率效率和最大输出功率相差不大,但是,光纤中的温度分布被有效地降低,因此,分布泵浦方式更为有效。 相似文献
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注入锁定准分子激光泵浦下氢受激喇曼散射的气压特性 总被引:2,自引:1,他引:1
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。 相似文献
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报道了一种基于空芯光子晶体光纤中氢气受激拉曼散射的新型1.7μm光纤激光光源。建立了仅包含泵浦光和一阶斯托克斯光的简单稳态耦合波方程,并进行了仿真计算。采用自制的1550 nm纳秒脉冲光纤放大器,泵浦一段长约3 m、充高压氢气的商用空芯光子晶体光纤,利用氢气分子的转动受激拉曼散射实现了1705 nm斯托克斯波的有效转换。气压为1.2 MPa时,最大平均输出功率约0.5 W(单脉冲能量约为2.5μJ),最大光光转换效率约为32%(相对总的泵浦功率)。研究结果为实现高功率1.7μm波段近红外激光输出提供了一条有效的新途径。 相似文献
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V. Pyragaite A. Stabinis R. Butkus R. Antipenkov A. Varanavi?ius 《Optics Communications》2010,283(6):1144-1151
We present simple analytical solutions of coupled wave equations describing chirped pulse parametric amplification under pump depletion. The evolution of the duration and spectrum of amplified pulses in OPA pumped by Gaussian and supergaussian pulses has been investigated both numerically and analytically. Also, the dependence of the energy conversion efficiency from pump to signal was determined for a range of parameter values, and an optimum ratio of signal and pump pulse durations was evaluated. 相似文献
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通过研究光参量啁啾脉冲放大过程转换效率随泵浦光啁啾参数的变化,以及信号光和泵浦光波长的对应关系,确立了信号光和泵浦光同步时实现线性啁啾匹配的方法。以磷酸二氢钾作为非线性晶体,研究了信号光和泵浦光之间的线性啁啾匹配和时间同步抖动对光参量啁啾脉冲放大后信号光脉冲波形和转换效率的影响。结果表明:在时间同步的情况下,线性啁啾匹配时的信号光脉冲波形很对称,转换效率也较高;在同步抖动程度一定的情况下,不同泵浦光啁啾参数时,信号光的增益及放大后的脉冲波形差异较大;在线性啁啾匹配程度一定时,信号光和泵浦光时间同步抖动越严重,放大信号光的脉冲波形变化越大,信号光增益越小,且转换效率也越低。 相似文献
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Wu Zhao-Hui Wei Xiao-Feng Zuo Yan-Lei Liu Lan-Qin Zhang Zhi-Meng Li Min Zhou Yu-Liang Su Jing-Qin 《中国物理 B》2015,24(1):14211-014211
Chirped wideband pump and seed pulses are usually considered for backward Raman amplification(BRA)in plasmas to achieve an extremely high-power laser pulse.However,current theoretical models only contain either a chirped pump or a chirped seed.In this paper,modified three-wave coupling equations are proposed for the BRA in the plasmas with both chirped wideband pump and seed.The simulation results can more precisely describe the experiments,such as the Princeton University experiment.The optimized chirp and bandwidth are determined based on the simulation to enhance the output intensity and efficiency. 相似文献
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Starting from the Maxwell‘s equation,and using the resonant-dipole equation together with the multilevel rate equations which take the effects of energy relaxation into consideration,we have derived a more realistic numerical model of the chirped pulse amplification for an ultra-broad band width laser amplifier.Numerical simulations of this model show that both the intensity profile and the energy fluence of the amplified chirped pulse are closely connected with the two relaxation effects:the relaxation of the thermalization among the components of the laser multiplets and the depletion of the lower laser level.The results are valuable for the design of ultra-broad bandwidth chirped pulse amplification lasers. 相似文献
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对发散光束抽运的光参量啁啾脉冲放大器的增益带宽进行了系统的理论研究.采用空间傅里叶变换和四阶Runge-Kutta算法,分别模拟了非衍射极限情况下的高斯光束和空间频谱为矩形的发散光束作为抽运光时的增益曲线.结果表明:不管是在可见光或是在近红外光谱区,用发散光束均可以明显地改善光参量啁啾脉冲放大系统的增益带宽.选取合适的发散角和抽运光强,可以获得高增益、宽谱带的信号光输出.
关键词:
光参量啁啾脉冲放大
增益带宽
发散角
高斯光束 相似文献
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CHEN Jianping LI Ruxin ZENG Zhinan WANG Xingtao & XU Zhizhan . Shanghai Institute of Optics Fine Mechanics Shanghai China . Beijing Aeronautical Technology Research Center Beijing China 《中国科学G辑(英文版)》2004,47(4):416-423
Equations of state (EOS) of matter at Mbar pressure are fundamental to numerous applications such as in astrophysics[1], plasma physics[2], inertial confinement fusion[3—6], and other related fields. Laser directly and indirectly induced shock wave compression of materials is an effective way to access these material states. Many recent experiments have been devoted to the study of laser driven shock waves and their use in the EOS measurement of strongly compressed materials[7]. It is well… 相似文献
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A theoretical and numerical investigation of small-signal Raman backscattering from a chirped pump pulse in plasma shows that an ultrashort probe pulse will grow superradiantly, i.e., with an amplitude that scales with the propagation length while contracting self-similarly. These features are commonly associated with the nonlinear stages of Raman amplification in the pump depletion and Compton regimes. We show that the superradiant scaling results in very broad-bandwidth amplification due to gain distributed in frequency as well as spatially. Since different frequencies excite the plasma at different positions, wave breaking is avoided, and prepulses and pedestals are substantially suppressed. Linear chirped pulse amplification in plasma could provide a very broad-bandwidth alternative to solid state laser amplifiers, potentially usable for optical pulses a few cycles in duration. 相似文献