Brillouin amplification is a new method to obtain high power hundred-picosecond laser pulses for shock ignition. The laser pulse＇s intensity can be amplified to 10 GW/cm^2 through this method. In order to determine t...Brillouin amplification is a new method to obtain high power hundred-picosecond laser pulses for shock ignition. The laser pulse＇s intensity can be amplified to 10 GW/cm^2 through this method. In order to determine the near-field quality, the relationship between the Brillouin amplification gain and the B integral in the stimulated Brillouin scattering（SBS） energy transfer process was studied, and numerical simulations and calculations were carried out to explain the process. For achieving an output intensity of 10 GW/cm^2 under the condition that the effect of small–scale self-focusing is insignificant in the Brillouin amplification, the influence of the configuration parameters on the Brillouin amplification and the B integral was investigated. The results showed that the 10 GW/cm^2 high power output can be obtained by optimizing the intensities of the pump and Stokes light and choosing an appropriate SBS medium.展开更多
Distributed optical fiber sensors have been widely used to monitor temperature, strain, vibration, and so on. Specifically, the sensors based on Brillouin scattering have been studied extensively to measure the strain...Distributed optical fiber sensors have been widely used to monitor temperature, strain, vibration, and so on. Specifically, the sensors based on Brillouin scattering have been studied extensively to measure the strain or temperature along an oDtical fiber.展开更多
The impacts of Brillouin pump depletion and nonlinear amplification in coded long-range Brillouin optical time-domain analysis （BOTDA） based on distributed Brillouin amplification （DBA） were studied. The error of ...The impacts of Brillouin pump depletion and nonlinear amplification in coded long-range Brillouin optical time-domain analysis （BOTDA） based on distributed Brillouin amplification （DBA） were studied. The error of Brillouin frequency shift （BFS） due to Brillouin pump depletion was compared for DBA-BOTDA using non-cyclic and cyclic coding. For non-cyclic coding, significant over- and under-shoots of BFS were found in the range with larger BFS variation, such as hot spot. The impact of Brillouin pump depletion can be reduced considerably by cyclic coding. Furthermore, to compensate the BFS error due to nonlinear amplification, a simple and effective log linearization was oroDosed and demonstrated.展开更多
The strong-coupling mode,called the"quasimode",is excited by stimulated Brillouin scattering(SBS)in high-intensity laser-plasma interactions.Also SBS of the quasimode competes with SBS of the fast mode(or sl...The strong-coupling mode,called the"quasimode",is excited by stimulated Brillouin scattering(SBS)in high-intensity laser-plasma interactions.Also SBS of the quasimode competes with SBS of the fast mode(or slow mode)in multiion species plasmas,thus leading to a low-frequency burst behavior of SBS reflectivity.Competition between the quasimode and the ion-acoustic wave(IAW)is an important saturation mechanism of SBS in high-intensity laser-plasma interactions.These results give a clear explanation of the low-frequency periodic burst behavior of SBS and should be considered as a saturation mechanism of SBS in high-intensity laser-plasma interactions.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61378007 and 61138005)the Fundamental Research Funds for the Central Universities,China(Grant No.HIT.IBRSEM.A.201409)
文摘Brillouin amplification is a new method to obtain high power hundred-picosecond laser pulses for shock ignition. The laser pulse＇s intensity can be amplified to 10 GW/cm^2 through this method. In order to determine the near-field quality, the relationship between the Brillouin amplification gain and the B integral in the stimulated Brillouin scattering（SBS） energy transfer process was studied, and numerical simulations and calculations were carried out to explain the process. For achieving an output intensity of 10 GW/cm^2 under the condition that the effect of small–scale self-focusing is insignificant in the Brillouin amplification, the influence of the configuration parameters on the Brillouin amplification and the B integral was investigated. The results showed that the 10 GW/cm^2 high power output can be obtained by optimizing the intensities of the pump and Stokes light and choosing an appropriate SBS medium.
基金supported by the National Natural Science Foundation of China(Nos.61377089 and 61527819)the International Science&Technology Cooperation Program of China(No.2014DFA50870)the Natural Science Foundation of Shanxi(Nos.2015011049 and201601D021069)
文摘Distributed optical fiber sensors have been widely used to monitor temperature, strain, vibration, and so on. Specifically, the sensors based on Brillouin scattering have been studied extensively to measure the strain or temperature along an oDtical fiber.
基金supported by the National Natural Science Foundation of China(NSFC)(No.61205079)the Scientific Research Fund of Sichuan Provincial Education Department(No.18ZA0401)the Open Experimental Programs of Sichuan Normal University(No.KFSY2017083)
文摘The impacts of Brillouin pump depletion and nonlinear amplification in coded long-range Brillouin optical time-domain analysis （BOTDA） based on distributed Brillouin amplification （DBA） were studied. The error of Brillouin frequency shift （BFS） due to Brillouin pump depletion was compared for DBA-BOTDA using non-cyclic and cyclic coding. For non-cyclic coding, significant over- and under-shoots of BFS were found in the range with larger BFS variation, such as hot spot. The impact of Brillouin pump depletion can be reduced considerably by cyclic coding. Furthermore, to compensate the BFS error due to nonlinear amplification, a simple and effective log linearization was oroDosed and demonstrated.
基金supported by the National Natural Science Foundation of China(Nos.11875091,11575035,11875093,11475030 and 11435011)National Postdoctoral Program for Innovative Talents(No.BX20180055)+1 种基金China Postdoctoral Science Foundation(No.2018M641274)Science Challenge Project(No.TZ2016005).
文摘The strong-coupling mode,called the"quasimode",is excited by stimulated Brillouin scattering(SBS)in high-intensity laser-plasma interactions.Also SBS of the quasimode competes with SBS of the fast mode(or slow mode)in multiion species plasmas,thus leading to a low-frequency burst behavior of SBS reflectivity.Competition between the quasimode and the ion-acoustic wave(IAW)is an important saturation mechanism of SBS in high-intensity laser-plasma interactions.These results give a clear explanation of the low-frequency periodic burst behavior of SBS and should be considered as a saturation mechanism of SBS in high-intensity laser-plasma interactions.
