Study on parameters and performances of SBS medium C_4Cl_6
The stimulated Brillouin scattering(SBS) medium hexachlorobuta-1,3-diene(C_4Cl_6) with little absorption coefficient is studied in terms of the absorption theory of medium to the light.Through basic physical parameters,the SBS parameters of C_4Cl_6 with the incident beam wavelength of 1 064 nm are determined.The absorption coefficient is 0.003 cm~(-1),the phonon lifetime is 0.25 ns and the gain coefficient is 4.9 cm·GW~(1).Whereas the Brillouin frequency is inversely proportional to the incident beam wavelength and the phonon is proportional to its square,the gain coefficient is wavelength-independent.In the single-cell SBS system pumped by Nd:YAG Q-switched laser,the SBS performances of C_4Cl_6 are studied.The results show that the saturation energy reflectivity of C_4Cl_6 is above 55%,well exceeding that of H_2O.As to the SBS pulse,the width is broader than that of H_2O and the rise time is shorter than that of CS_2.The characteristics of small absorption coefficient and short phonon lifetime,making C_4Cl_6 suitable for the amplifier medium,will be of importance in optimizing the choice of SBS medium and improving the SBS system performance.