Spectrum evolutions of spontaneous and pump-depleted stimulated Brillouin scatterings in liquid media  

作　　者：高玮 吕志伟 何伟明 哈斯乌力吉 张赞 

机构地区：[1]Institute of Opto-Electronics, Harbin Institute of Technology [2]Department of Applied Physics, Harbin University of Science and Technology

出　　处：《Chinese Physics B》2008年第10期3765-3770,共6页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant No 60778019);the Program of Excellent Teamin Harbin Institute of Technology, China;the Program of Science and Technology of Education the Bureau of Heilongjiang Province, China (Grant No 11521048)

摘　　要：A theoretical model for calculating spontaneous and stimulated Brillouin scattering（SBS） spectra is described. An empirical formula for the Stokes output spectral linewidth, a function of spontaneous Brillouin linewidth and the exponential gain coefficient, is obtained by the calculated data fitting. The formula holds true for two cases involving pump undepletion and depletion. The lineshape change from spontaneous to highly pump-depleted SBS spectra is also investigated. The result shows that for the pump power below the SBS threshold, the Stokes output spectral lincshape evolves from Lorentzian to approximately Gaussian as the pump power increases. For the pump power near or beyond the threshold, the SBS spectrum is in the form of a steady Gaussian profile, and the spectral linewidth comes to a certain value about 7 times narrower than the spontaneous one. The theoretical results are experimentally demonstrated by using several common liquid media.A theoretical model for calculating spontaneous and stimulated Brillouin scattering（SBS） spectra is described. An empirical formula for the Stokes output spectral linewidth, a function of spontaneous Brillouin linewidth and the exponential gain coefficient, is obtained by the calculated data fitting. The formula holds true for two cases involving pump undepletion and depletion. The lineshape change from spontaneous to highly pump-depleted SBS spectra is also investigated. The result shows that for the pump power below the SBS threshold, the Stokes output spectral lincshape evolves from Lorentzian to approximately Gaussian as the pump power increases. For the pump power near or beyond the threshold, the SBS spectrum is in the form of a steady Gaussian profile, and the spectral linewidth comes to a certain value about 7 times narrower than the spontaneous one. The theoretical results are experimentally demonstrated by using several common liquid media.

关 键 词：Brillouin scattering spectrum evolution LINEWIDTH LINESHAPE 

分 类 号：O437.2[机械工程—光学工程]